4.0.7

Adding extract_from functionality + unit tests

.github/ISSUE_TEMPLATE/bug_report.md

@@ -9,7 +9,8 @@ assignees: ''
 
 Before submitting an issue, please ensure that you have read the documentation:
 
-* Basics is an overview of how to use simdjson and its APIs: https://github.com/simdjson/simdjson/blob/master/doc/basics.md
+* Basics is an overview of how to use simdjson and its APIs to parse JSON: https://github.com/simdjson/simdjson/blob/master/doc/basics.md
+* Builder is an overview of how to use simdjson to generate JSON: https://github.com/simdjson/simdjson/blob/master/doc/builder.md
 * Performance shows some more advanced scenarios and how to tune for them: https://github.com/simdjson/simdjson/blob/master/doc/performance.md
 * Contributing: https://github.com/simdjson/simdjson/blob/master/CONTRIBUTING.md
 * We follow the [JSON specification as described by RFC 8259](https://www.rfc-editor.org/rfc/rfc8259.txt) (T. Bray, 2017). If you wish to support features that are not part of RFC 8259, then you should not refer to your issue as a bug.
@@ -55,6 +56,8 @@ We support up-to-date 64-bit ARM and x64 FreeBSD, macOS, Windows and Linux syste
 pre-release version of a compiler, do not report it as a bug to simdjson. However, we always
 invite contributions either in the form an analysis or of a code contribution.
 
+Under Windows, we support Visual Studio (both with LLVM and without). We do not support MinGW and other alternate compiler systems. Windows users should be aware that there [is a long-running bug with GCC under Windows](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54412).
+
 **Indicate whether you are willing or able to provide a bug fix as a pull request**
 
 If you plan to contribute to simdjson, please read our guide:

.github/ISSUE_TEMPLATE/feature_request.md

@@ -9,7 +9,8 @@ assignees: ''
 
 Before submitting an issue, please ensure that you have read the documentation:
 
-* Basics is an overview of how to use simdjson and its APIs: https://github.com/simdjson/simdjson/blob/master/doc/basics.md
+* Basics is an overview of how to use simdjson and its APIs to parse JSON: https://github.com/simdjson/simdjson/blob/master/doc/basics.md
+* Builder is an overview of how to use simdjson to generate JSON: https://github.com/simdjson/simdjson/blob/master/doc/builder.md
 * Performance shows some more advanced scenarios and how to tune for them: https://github.com/simdjson/simdjson/blob/master/doc/performance.md
 * Contributing: https://github.com/simdjson/simdjson/blob/master/CONTRIBUTING.md
 * We follow the [JSON specification as described by RFC 8259](https://www.rfc-editor.org/rfc/rfc8259.txt) (T. Bray, 2017).

.github/ISSUE_TEMPLATE/standard-issue-template.md

@@ -9,7 +9,8 @@ assignees: ''
 
 Before submitting an issue, please ensure that you have read the documentation:
 
-* Basics is an overview of how to use simdjson and its APIs: https://github.com/simdjson/simdjson/blob/master/doc/basics.md
+* Basics is an overview of how to use simdjson and its APIs to parse JSON: https://github.com/simdjson/simdjson/blob/master/doc/basics.md
+* Builder is an overview of how to use simdjson to generate JSON: https://github.com/simdjson/simdjson/blob/master/doc/builder.md
 * Performance shows some more advanced scenarios and how to tune for them: https://github.com/simdjson/simdjson/blob/master/doc/performance.md
 * Contributing: https://github.com/simdjson/simdjson/blob/master/CONTRIBUTING.md
 * We follow the [JSON specification as described by RFC 8259](https://www.rfc-editor.org/rfc/rfc8259.txt) (T. Bray, 2017).

.github/pull_request_template.md

@@ -1,8 +1,53 @@
+Short title (summary):
+
+Description
+- What did you change and why? (1-3 sentences)
+- Issue reproduced / related issue: link the issue if relevant (e.g. #123)
+
+Type of change
+- [ ] Bug fix
+- [ ] New feature
+- [ ] Refactor / cleanup
+- [ ] Documentation / tests
+- [ ] Other (please describe):
+
+How to verify / test
+- Add additional tests to verify bugs or new features.
+- If you claim performance gains, you should provide benchmark numbers using high quality benchmarking code.
 
 
-Our tests check whether you have introduced trailing white space. If such a test fails, please check the "artifacts button" above, which if you click it gives a link to a downloadable file to help you identify the issue. You can also run scripts/remove_trailing_whitespace.sh locally if you have a bash shell and the sed command available on your system.
+Please read before contributing:
+- CONTRIBUTING: https://github.com/simdjson/simdjson/blob/master/CONTRIBUTING.md
+- HACKING: https://github.com/simdjson/simdjson/blob/master/HACKING.md
 
-If you plan to contribute to simdjson, please read our
 
-CONTRIBUTING guide: https://github.com/simdjson/simdjson/blob/master/CONTRIBUTING.md and our
-HACKING guide: https://github.com/simdjson/simdjson/blob/master/HACKING.md
+
+If you can, we recommend running our tests with the sanitizers turned on.
+For non-Visual Studio users, it is as easy as doing:
+
+
+
+```bash
+cmake -B build -D SIMDJSON_SANITIZE=ON -D SIMDJSON_DEVELOPER_MODE=ON
+cmake --build build
+ctest --test-dir build
+```
+
+
+Our CI checks, among other things, for trailing whitespace. If a test fails for that reason,
+use the "artifacts" button to download the artifact and inspect the problematic lines,
+or run `scripts/remove_trailing_whitespace.sh` locally if you have a bash shell and `sed`.
+
+
+Checklist before submitting
+- [ ] I added/updated tests covering my change (if applicable)
+- [ ] Code builds locally and passes my check
+- [ ] Documentation / README updated if needed
+- [ ] Commits are atomic and messages are clear
+- [ ] I linked the related issue (if applicable)
+
+Final notes
+- For large PRs, prefer smaller incremental PRs or request staged review.
+
+Thanks for the contribution!
+

.github/workflows/emscripten.yml

@@ -0,0 +1,17 @@
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: mymindstorm/setup-emsdk@6ab9eb1bda2574c4ddb79809fc9247783eaf9021 # v14
+      - name: Verify
+        run: emcc -v
+      - name: Checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v3.6.0
+      - name: Configure
+        run: emcmake cmake -B build
+      - name: Build # We build but do not test
+        run: cmake --build build

.github/workflows/fix-trailing-whitespace.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 
 jobs:
   whitespace:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - name: Remove whitespace and check the diff

.github/workflows/rvv-1024-clang-18.yml

@@ -0,0 +1,29 @@
+name: Ubuntu rvv VLEN=1024 (clang 18)
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install packages
+      run: |
+        sudo apt-get update -q -y
+        sudo apt-get install -y cmake make g++-riscv64-linux-gnu qemu-user-static clang-18
+    - name: Build
+      run: |
+        CXX=clang++-18 CXXFLAGS="--target=riscv64-linux-gnu -march=rv64gcv_zvbb" \
+        cmake --toolchain=cmake/toolchains-ci/riscv64-linux-gnu.cmake -DCMAKE_BUILD_TYPE=Release -B build
+        cmake --build build/ -j$(nproc)
+    - name: Test VLEN=1024
+      run: |
+        export QEMU_LD_PREFIX="/usr/riscv64-linux-gnu"
+        export QEMU_CPU="rv64,v=on,zvbb=on,vlen=1024,rvv_ta_all_1s=on,rvv_ma_all_1s=on"
+        ctest --timeout 1800 --output-on-failure --test-dir build -j $(nproc)

.github/workflows/rvv-128-clang-17.yml

@@ -0,0 +1,29 @@
+name: Ubuntu rvv VLEN=128 (clang 17)
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install packages
+      run: |
+        sudo apt-get update -q -y
+        sudo apt-get install -y cmake make g++-riscv64-linux-gnu qemu-user-static clang-17
+    - name: Build
+      run: |
+        CXX=clang++-17 CXXFLAGS="--target=riscv64-linux-gnu -march=rv64gcv" \
+        cmake --toolchain=cmake/toolchains-ci/riscv64-linux-gnu.cmake -DCMAKE_BUILD_TYPE=Release -B build
+        cmake --build build/ -j$(nproc)
+    - name: Test VLEN=128
+      run: |
+        export QEMU_LD_PREFIX="/usr/riscv64-linux-gnu"
+        export QEMU_CPU="rv64,v=on,vlen=128,rvv_ta_all_1s=on,rvv_ma_all_1s=on"
+        ctest --timeout 1800 --output-on-failure --test-dir build -j $(nproc)

.github/workflows/rvv-256-gcc-14.yml

@@ -0,0 +1,29 @@
+name: Ubuntu rvv VLEN=256 (gcc 14)
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install packages
+      run: |
+        sudo apt-get update -q -y
+        sudo apt-get install -y cmake make g++-14-riscv64-linux-gnu qemu-user-static
+    - name: Build
+      run: |
+        CXX=riscv64-linux-gnu-g++-14 CXXFLAGS=-march=rv64gcv \
+        cmake --toolchain=cmake/toolchains-ci/riscv64-linux-gnu.cmake -DCMAKE_BUILD_TYPE=Release -B build
+        cmake --build build/ -j$(nproc)
+    - name: Test VLEN=256
+      run: |
+        export QEMU_LD_PREFIX="/usr/riscv64-linux-gnu"
+        export QEMU_CPU="rv64,v=on,zvbb=on,vlen=256,rvv_ta_all_1s=on,rvv_ma_all_1s=on"
+        ctest --timeout 1800 --output-on-failure --test-dir build -j $(nproc)

.github/workflows/ubuntu20-gcc8.yml

@@ -1,38 +0,0 @@
-name: Ubuntu 20.04 CI (GCC 8)
-
-on: [push, pull_request]
-
-jobs:
-  ubuntu-build:
-    if: >-
-      ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
-      ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
-    env:
-      CXX: g++-8
-      CC: gcc-8
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/cache@v4
-        with:
-          path: dependencies/.cache
-          key: ${{ hashFiles('dependencies/CMakeLists.txt') }}
-      - name: Install GCC 8
-        run: sudo apt-get install -y g++-8
-      - name: Use cmake
-        run: |
-          mkdir builddebug &&
-          cd builddebug &&
-          cmake -DCMAKE_BUILD_TYPE=Debug -DSIMDJSON_GOOGLE_BENCHMARKS=OFF -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure -LE explicitonly -j   &&
-          cd .. &&
-          mkdir build &&
-          cd build &&
-          cmake  -DSIMDJSON_GOOGLE_BENCHMARKS=ON -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_PREFIX:PATH=destination ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure -LE explicitonly -j   &&
-          cmake --install . &&
-          echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp && c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson && ./linkandrun jsonexamples/twitter.json &&
-          cd ../tests/installation_tests/find &&
-          mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../build/destination .. &&  cmake --build .

.github/workflows/ubuntu20.yml

@@ -1,47 +0,0 @@
-name: Ubuntu 20.04 CI (GCC 9)
-
-on: [push, pull_request]
-
-jobs:
-  ubuntu-build:
-    if: >-
-      ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
-      ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/cache@v4
-        with:
-          path: dependencies/.cache
-          key: ${{ hashFiles('dependencies/CMakeLists.txt') }}
-      - name: Use cmake to build just the library
-        run: |
-          mkdir buildjustlib &&
-          cd buildjustlib &&
-          cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=OFF -DSIMDJSON_DEVELOPER_MODE=OFF -DCMAKE_INSTALL_PREFIX:PATH=destination ..  &&
-          cmake --build .   &&
-          cmake --install . &&
-          echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp &&
-          c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson &&
-          cd ../tests/installation_tests/find &&
-          mkdir buildjustlib &&
-          cd buildjustlib &&
-          cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../buildjustlib/destination .. &&
-          cmake --build .
-      - name: Use cmake
-        run: |
-          mkdir builddebug &&
-          cd builddebug &&
-          cmake -DCMAKE_BUILD_TYPE=Debug -DSIMDJSON_GOOGLE_BENCHMARKS=OFF -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure -LE explicitonly -j   &&
-          cd .. &&
-          mkdir build &&
-          cd build &&
-          cmake  -DSIMDJSON_GOOGLE_BENCHMARKS=ON -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_PREFIX:PATH=destination ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure -LE explicitonly -j   &&
-          cmake --install . &&
-          echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp && c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson && ./linkandrun jsonexamples/twitter.json &&
-          cd ../tests/installation_tests/find &&
-          mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../build/destination .. &&  cmake --build .

.github/workflows/ubuntu22-cxx20.yml

@@ -14,20 +14,52 @@ jobs:
         with:
           path: dependencies/.cache
           key: ${{ hashFiles('dependencies/CMakeLists.txt') }}
-      - name: Use cmake
+
+      - name: Configure Debug Build
         run: |
-          mkdir builddebug &&
-          cd builddebug &&
-          CXX=g++-12 cmake -DSIMDJSON_CXX_STANDARD=20 -DCMAKE_BUILD_TYPE=Debug -DSIMDJSON_GOOGLE_BENCHMARKS=OFF -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure -LE explicitonly -j   &&
-          cd .. &&
-          mkdir build &&
-          cd build &&
-          CXX=g++-12 cmake -DSIMDJSON_CXX_STANDARD=20  -DSIMDJSON_GOOGLE_BENCHMARKS=ON -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_PREFIX:PATH=destination ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure -LE explicitonly -j   &&
-          cmake --install . &&
-          echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp && c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson && ./linkandrun jsonexamples/twitter.json &&
-          cd ../tests/installation_tests/find &&
-          mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../build/destination .. &&  cmake --build .
+          CXX=g++-12 cmake -DSIMDJSON_CXX_STANDARD=20 -DCMAKE_BUILD_TYPE=Debug -DSIMDJSON_GOOGLE_BENCHMARKS=OFF -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF -B builddebug
+
+      - name: Compile Debug Build
+        run: |
+          cmake --build builddebug
+
+      - name: Test Debug Build
+        run: |
+          ctest --output-on-failure -LE explicitonly -j --test-dir builddebug
+
+      - name: Configure Release Build
+        run: |
+          CXX=g++-12 cmake -DSIMDJSON_CXX_STANDARD=20 -DSIMDJSON_GOOGLE_BENCHMARKS=ON -DSIMDJSON_DEVELOPER_MODE=ON -DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_PREFIX:PATH=destination -B build
+
+      - name: Compile Release Build
+        run: |
+          cmake --build build
+
+      - name: Test Release Build
+        run: |
+          ctest --output-on-failure -LE explicitonly -j --test-dir build
+
+      - name: Install Release Build
+        run: |
+          cmake --install build
+
+      - name: Generate Example Code
+        run: |
+          echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp
+
+      - name: Compile Example Code
+        run: |
+          c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson
+
+      - name: Run Example Code
+        run: |
+          ./linkandrun jsonexamples/twitter.json
+
+      - name: Configure Find Tests
+        run: |
+          cd tests/installation_tests/find && \
+          cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../destination -B build
+
+      - name: Compile Find Tests
+        run: |
+          cd tests/installation_tests/find && cmake --build build

.github/workflows/ubuntu24-checkperf.yml

@@ -13,7 +13,7 @@ jobs:
     if: >-
       ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
       ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4

.github/workflows/ubuntu24-cxx20-noexcept.yml

@@ -0,0 +1,22 @@
+name: Ubuntu 24.04 CI (CXX 20, noexcept)
+
+on: [push, pull_request]
+jobs:
+  ubuntu-build:
+    if: >-
+      ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
+      ! contains(toJSON(github.event.commits.*.message), '[skip github]')
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        cxx: [g++-13, clang++-16]
+    steps:
+      - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
+      - name: Prepare
+        run: cmake -DSIMDJSON_CXX_STANDARD=20 -DSIMDJSON_EXCEPTIONS=OFF -DSIMDJSON_DEVELOPER_MODE=ON  -B build
+        env:
+          CXX: ${{matrix.cxx}}
+      - name: Build
+        run: cmake --build build -j=2
+      - name: Test
+        run: ctest --output-on-failure --test-dir build

.github/workflows/ubuntu24-noexcept.yml

@@ -7,7 +7,7 @@ jobs:
     if: >-
       ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
       ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4
@@ -31,4 +31,4 @@ jobs:
           echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp && c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson && ./linkandrun jsonexamples/twitter.json &&
           mkdir testfindpackage &&
           cd testfindpackage &&
-          echo -e 'cmake_minimum_required(VERSION 3.1)\nproject(simdjsontester)\nset(CMAKE_CXX_STANDARD 17)\nfind_package(simdjson REQUIRED)'> CMakeLists.txt && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../destination .. &&  cmake --build .
+          echo -e 'cmake_minimum_required(VERSION 3.14)\nproject(simdjsontester)\nset(CMAKE_CXX_STANDARD 17)\nfind_package(simdjson REQUIRED)'> CMakeLists.txt && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../destination .. &&  cmake --build .

.github/workflows/ubuntu24-nothread.yml

@@ -7,7 +7,7 @@ jobs:
     if: >-
       ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
       ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4
@@ -31,4 +31,4 @@ jobs:
           echo -e '#include <simdjson.h>\nint main(int argc,char**argv) {simdjson::dom::parser parser;simdjson::dom::element tweets = parser.load(argv[1]); }' > tmp.cpp && c++ -Idestination/include -Ldestination/lib -std=c++17 -Wl,-rpath,destination/lib -o linkandrun tmp.cpp -lsimdjson && ./linkandrun jsonexamples/twitter.json &&
           mkdir testfindpackage &&
           cd testfindpackage &&
-          echo -e 'cmake_minimum_required(VERSION 3.1)\nproject(simdjsontester)\nset(CMAKE_CXX_STANDARD 17)\nfind_package(simdjson REQUIRED)'> CMakeLists.txt && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../destination .. &&  cmake --build .
+          echo -e 'cmake_minimum_required(VERSION 3.14)\nproject(simdjsontester)\nset(CMAKE_CXX_STANDARD 17)\nfind_package(simdjson REQUIRED)'> CMakeLists.txt && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../destination .. &&  cmake --build .

.github/workflows/ubuntu24-sani.yml

@@ -7,7 +7,7 @@ jobs:
     if: >-
       ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
       ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4
@@ -25,7 +25,7 @@ jobs:
     if: >-
       ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
       ! contains(toJSON(github.event.commits.*.message), '[skip github]')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4

.github/workflows/vs17-ci-sani.yml

@@ -0,0 +1,30 @@
+name: VS17-CI-SANITIZE
+
+on: [push, pull_request]
+
+jobs:
+  ci:
+    if: >-
+      ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
+      ! contains(toJSON(github.event.commits.*.message), '[skip github]')
+    name: windows-vs17
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {gen: Visual Studio 17 2022, arch: x64, shared: OFF, build_type: Debug}
+          - {gen: Visual Studio 17 2022, arch: x64, shared: OFF, build_type: Release}
+          - {gen: Visual Studio 17 2022, arch: x64, shared: OFF, build_type: RelWithDebInfo}
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: Configure
+      run: |
+        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}} -DSANITIZE=ON -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -DBUILD_SHARED_LIBS=${{matrix.shared}} -B build
+    - name: Build
+      run: cmake --build build --config ${{matrix.build_type}} --verbose
+    - name: Run tests
+      run: |
+        cd build
+        ctest -C ${{matrix.build_type}}  -LE explicitonly  --output-on-failure

.gitignore

@@ -38,7 +38,7 @@ cmake-build-release/
 .history/
 
 # Visual Studio artifacts
-/VS/
+/.vs/
 
 # C/C++ build outputs
 .build/
@@ -106,4 +106,4 @@ objs
 !.vscode/extensions.json
 
 # clangd
-.cache
+.cache

.vscode/settings.json

@@ -3,6 +3,9 @@
         {"column": 95 },
         {"column": 120 }
     ],
+    "cmake.configureArgs": [
+        "-DSIMDJSON_DEVELOPER_MODE=ON"
+    ],
     "files.trimTrailingWhitespace": true,
     "files.associations": {
         ".clangd": "yaml",

CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.14)
 project(
     simdjson
     # The version number is modified by tools/release.py
-    VERSION 3.12.3
+    VERSION 4.0.7
     DESCRIPTION "Parsing gigabytes of JSON per second"
     HOMEPAGE_URL "https://simdjson.org/"
     LANGUAGES CXX C
@@ -20,8 +20,8 @@ string(
 # ---- Options, variables ----
 
 # These version numbers are modified by tools/release.py
-set(SIMDJSON_LIB_VERSION "25.0.0" CACHE STRING "simdjson library version")
-set(SIMDJSON_LIB_SOVERSION "25" CACHE STRING "simdjson library soversion")
+set(SIMDJSON_LIB_VERSION "27.0.0" CACHE STRING "simdjson library version")
+set(SIMDJSON_LIB_SOVERSION "27" CACHE STRING "simdjson library soversion")
 
 option(SIMDJSON_BUILD_STATIC_LIB "Build simdjson_static library along with simdjson (only makes sense if BUILD_SHARED_LIBS=ON)" OFF)
 if(SIMDJSON_BUILD_STATIC_LIB AND NOT BUILD_SHARED_LIBS)
@@ -43,6 +43,20 @@ if(SIMDJSON_DISABLE_DEPRECATED_API)
   )
 endif()
 
+if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.25.0")
+    option(SIMDJSON_STATIC_REFLECTION "Enables static reflection (experimental), requires C++26" OFF)
+else()
+    set(SIMDJSON_STATIC_REFLECTION OFF CACHE BOOL "Enables static reflection (experimental)" FORCE)
+    message(WARNING "SIMDJSON_STATIC_REFLECTION is disabled because your CMake version is below 3.25")
+endif()
+
+if(SIMDJSON_STATIC_REFLECTION)
+  simdjson_add_props(
+      target_compile_definitions PUBLIC
+      SIMDJSON_STATIC_REFLECTION=1
+  )
+endif()
+
 option(SIMDJSON_DEVELOPMENT_CHECKS "Enable development-time aids, such as \
 checks for incorrect API usage. Enabled by default in DEBUG." OFF)
 if(SIMDJSON_DEVELOPMENT_CHECKS)
@@ -84,7 +98,7 @@ set_target_properties(
 )
 
 # FIXME: Use proper CMake integration for exports
-if(MSVC AND BUILD_SHARED_LIBS)
+if(WIN32 AND BUILD_SHARED_LIBS)
   target_compile_definitions(
       simdjson
       PRIVATE SIMDJSON_BUILDING_WINDOWS_DYNAMIC_LIBRARY=1
@@ -98,7 +112,16 @@ simdjson_add_props(
     PRIVATE "$<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src>"
 )
 
-simdjson_add_props(target_compile_features PUBLIC cxx_std_11)
+if(SIMDJSON_STATIC_REFLECTION)
+  # We would like to require C++26, but no compiler supports that!
+  # This is a hack:
+  simdjson_add_props(
+      target_compile_options PUBLIC
+      -freflection -fexpansion-statements -stdlib=libc++ -std=c++26
+  )
+else()
+  simdjson_add_props(target_compile_features PUBLIC cxx_std_11)
+endif()
 
 # workaround for GNU GCC poor AVX load/store code generation
 if(
@@ -111,6 +134,12 @@ if(
   )
 endif()
 
+option(SIMDJSON_MINUS_ZERO_AS_FLOAT "Treat -0 as a floating-point value" OFF)
+
+if(SIMDJSON_MINUS_ZERO_AS_FLOAT)
+  simdjson_add_props(target_compile_definitions PRIVATE SIMDJSON_MINUS_ZERO_AS_FLOAT=1)
+endif(SIMDJSON_MINUS_ZERO_AS_FLOAT)
+
 if(CMAKE_SYSTEM_PROCESSOR MATCHES "^(loongarch64)$")
     option(SIMDJSON_PREFER_LSX "Prefer LoongArch SX" ON)
     include(CheckCXXCompilerFlag)

Doxyfile

@@ -38,7 +38,7 @@ PROJECT_NAME           = simdjson
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = "3.12.3"
+PROJECT_NUMBER         = "4.0.7"
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

HACKING.md

@@ -20,13 +20,54 @@ If you plan to contribute to simdjson, please read our [CONTRIBUTING](https://gi
 Build Quickstart
 ------------------------------
 
+For non-Windows system,
+
 ```bash
-mkdir build
-cd build
-cmake -D SIMDJSON_DEVELOPER_MODE=ON ..
-cmake --build .
+cmake -B -D SIMDJSON_DEVELOPER_MODE=ON ..
+cmake --build build
+ctest --test-dir build
 ```
 
+It is similar for Visual Studio users, please see the CMake or Visual Studio documentation.
+
+By default the library is built in Release mode.
+
+
+Assertions and development checks
+------------------------------
+
+We do not use conventional `assert` in simdjson. Instead we use the macro
+`SIMDJSON_ASSUME`:
+
+```cpp
+SIMDJSON_ASSUME(something_that_is_true());
+```
+
+Sometimes, you need to do a bit more work that a simple check.
+The `SIMDJSON_DEVELOPMENT_CHECKS` macro is true only in Debug mode unless manually set.
+It is acceptable to add checks that you would not do in Release mode as long as
+they are guarded:
+
+```cpp
+#if SIMDJSON_DEVELOPMENT_CHECKS
+// do sanity checks here
+```
+
+
+Working with sanitizers
+------------------------------
+
+The simdjson library must be memory-safe. We cannot allow buffer overruns.
+During development, if you system supports it, we recommend configuring
+the project with `-D SIMDJSON_SANITIZE=ON`.
+
+```bash
+cmake -B -D SIMDJSON_SANITIZE=ON -D SIMDJSON_DEVELOPER_MODE=ON ..
+cmake --build build
+ctest --test-dir build
+```
+
+
 Design notes
 ------------------------------
 
@@ -103,12 +144,9 @@ simdjson's source structure, from the top level, looks like this:
     * generic/stage2/*.h: `simdjson::<implementation>::stage2` namespace. Generic implementation of the tape creator, which consumes the index from stage 1 and actually parses numbers and string and such. Used for the DOM interface.
 
 Other important files and directories:
-* **.drone.yml:** Definitions for Drone CI.
-* **.appveyor.yml:** Definitions for Appveyor CI (Windows).
-* **.circleci:** Definitions for Circle CI.
 * **.github/workflows:** Definitions for GitHub Actions (CI).
 * **singleheader:** Contains generated `simdjson.h` and `simdjson.cpp` that we release. The files `singleheader/simdjson.h` and `singleheader/simdjson.cpp` should never be edited by hand.
-* **singleheader/amalgamate.py:** Generates `singleheader/simdjson.h` and `singleheader/simdjson.cpp` for release (python script).
+* **singleheader/amalgamate.py:** Generates `singleheader/simdjson.h` and `singleheader/simdjson.cpp` for release (python script). If you add a new implementation (e.g., rvv), you need to edit this file (IMPLEMENTATIONS).
 * **benchmark:** This is where we do benchmarking. Benchmarking is core to every change we make; the
   cardinal rule is don't regress performance without knowing exactly why, and what you're trading
   for it. Many of our benchmarks are microbenchmarks. We are effectively doing controlled scientific experiments for the purpose of understanding what affects our performance. So we simplify as much as possible. We try to avoid irrelevant factors such as page faults, interrupts, unnecessary system calls. We recommend checking the performance as follows:

README.md

@@ -1,5 +1,3 @@
-
-[![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/simdjson.svg)](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:simdjson)
 [![][license img]][license] [![][licensemit img]][licensemit]
 
 
@@ -63,6 +61,8 @@ Real-world usage
 - [fastgron](https://github.com/adamritter/fastgron)
 - [WasmEdge](https://wasmedge.org)
 - [RonDB](https://github.com/logicalclocks/rondb)
+- [GreptimeDB](https://github.com/GreptimeTeam/greptimedb)
+- [mamba](https://github.com/mamba-org/mamba)
 
 
 If you are planning to use simdjson in a product, please work from one of our releases.
@@ -108,6 +108,7 @@ Documentation
 Usage documentation is available:
 
 * [Basics](doc/basics.md) is an overview of how to use simdjson and its APIs.
+* [Builder](doc/builder.md) is an overview of how to efficiently write JSON strings using simdjson.
 * [Performance](doc/performance.md) shows some more advanced scenarios and how to tune for them.
 * [Implementation Selection](doc/implementation-selection.md) describes runtime CPU detection and
   how you can work with it.
@@ -117,6 +118,7 @@ Godbolt
 -------------
 
 Some users may want to browse code along with the compiled assembly. You want to check out the following lists of examples:
+* [C++26 reflection example](https://godbolt.org/z/K3Px64TqK)
 * [simdjson examples with errors handled through exceptions](https://godbolt.org/z/7G5qE4sr9)
 * [simdjson examples with errors without exceptions](https://godbolt.org/z/e9dWb9E4v)
 

benchmark/CMakeLists.txt

@@ -4,6 +4,9 @@ add_subdirectory(dom)
 include_directories( . linux )
 link_libraries(simdjson-windows-headers test-data)
 link_libraries(simdjson)
+if(SIMDJSON_STATIC_REFLECTION)
+  add_compile_definitions(SIMDJSON_STATIC_REFLECTION=1)
+endif(SIMDJSON_STATIC_REFLECTION)
 
 add_executable(benchfeatures benchfeatures.cpp)
 add_executable(get_corpus_benchmark get_corpus_benchmark.cpp)
@@ -32,3 +35,16 @@ if (TARGET benchmark::benchmark)
   endif()
 endif()
 
+
+include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag("-std=c++20" SIMDJSON_COMPILER_SUPPORTS_CXX20)
+if(SIMDJSON_STATIC_REFLECTION)
+  add_subdirectory(static_reflect)
+else()
+  if(SIMDJSON_EXCEPTIONS AND SIMDJSON_COMPILER_SUPPORTS_CXX20)
+    add_subdirectory(from)
+    add_subdirectory(car_builder)
+  endif()
+endif(SIMDJSON_STATIC_REFLECTION)
+
+

benchmark/benchmark_reflection_usage_compilation.sh

@@ -0,0 +1,618 @@
+#!/bin/bash
+
+# JSON Parsing Compilation Benchmark: Reflection Usage vs Manual Parsing
+# Compares compilation times when ACTUALLY USING reflection for parsing vs manual parsing
+# This measures the compile-time cost of reflection-based automatic deserialization
+
+set -e
+
+echo "=== simdjson Reflection Usage Compilation Benchmark ==="
+echo "Measuring compilation impact of ACTUALLY USING reflection for parsing"
+echo "Starting at: $(date)"
+echo
+echo "╔════════════════════════════════════════════════════════════════════════════╗"
+echo "║                              METHODOLOGY                                   ║"
+echo "╠════════════════════════════════════════════════════════════════════════════╣"
+echo "║                                                                            ║"
+echo "║ FAIR COMPARISON STRATEGY:                                                  ║"
+echo "║ This benchmark compares two DIFFERENT approaches to parsing the same JSON: ║"
+echo "║                                                                            ║"
+echo "║ • MANUAL PARSING: Traditional simdjson with explicit .get() calls          ║"
+echo "║   - Uses doc[\"field\"].get(variable) for each field                         ║"
+echo "║   - No reflection involved                                                 ║"
+echo "║                                                                            ║"
+echo "║ • REFLECTION PARSING: Automatic deserialization with reflection            ║"
+echo "║   - Uses doc.get<MyStruct>() for automatic field mapping                   ║"
+echo "║   - Relies on compile-time reflection to generate parsing code             ║"
+echo "║                                                                            ║"
+echo "║ WHAT WE'RE MEASURING:                                                      ║"
+echo "║ • Compile-time cost of reflection-based automatic deserialization          ║"
+echo "║ • Template instantiation overhead for reflection parsing                   ║"
+echo "║ • Code generation complexity from using reflection features                ║"
+echo "║                                                                            ║"
+echo "║ TEST SCENARIOS:                                                            ║"
+echo "║                                                                            ║"
+echo "║ 1. SIMPLE STRUCT: Basic fields (string, int, bool)                         ║"
+echo "║    - Measures baseline reflection overhead                                 ║"
+echo "║                                                                            ║"
+echo "║ 2. NESTED STRUCT: Multiple levels of nested objects                        ║"
+echo "║    - Measures reflection complexity scaling                                ║"
+echo "║                                                                            ║"
+echo "║ 3. COMPLEX STRUCT: Arrays, optional fields, mixed types                    ║"
+echo "║    - Measures real-world reflection usage impact                           ║"
+echo "║                                                                            ║"
+echo "║ WHY THIS IS MEANINGFUL:                                                    ║"
+echo "║ • Shows actual cost of using reflection features                           ║"
+echo "║ • Measures compile-time code generation overhead                           ║"
+echo "║ • Helps developers understand reflection's compilation impact              ║"
+echo "║ • Compares equivalent functionality implemented two different ways         ║"
+echo "║                                                                            ║"
+echo "╚════════════════════════════════════════════════════════════════════════════╝"
+echo
+
+# Configuration
+ITERATIONS=10
+JOBS=4
+
+# ───────────────────────────── BOX-PRINT HELPER ────────────────────────────
+BOX_WIDTH=74                               # characters between the pipes
+print_box_line() {                         # usage: print_box_line "text"
+  printf "║ %-*s ║\n" "${BOX_WIDTH}" "$1"
+}
+
+# Function to test if a compiler supports reflection with debug output
+test_reflection_support() {
+    local compiler="$1"
+    echo "  → Testing compiler: $compiler"
+
+    if [ ! -x "$compiler" ] && ! command -v "$compiler" >/dev/null 2>&1; then
+        echo "  → Compiler not found or not executable"
+        return 1
+    fi
+
+    # Check compiler version first
+    echo "  → Compiler version: $("$compiler" --version 2>/dev/null | head -n1 || echo "version check failed")"
+
+    # Simple test: check if compiler accepts reflection flags
+    local test_file=$(mktemp /tmp/reflection_test_XXXXXX.cpp)
+    cat > "$test_file" << 'EOF'
+int main() {
+    return 0;
+}
+EOF
+
+    echo "  → Testing basic reflection flags..."
+    local test_exe=$(mktemp /tmp/reflection_test_XXXXXX)
+    local basic_result=$("$compiler" -freflection -fexpansion-statements -std=c++26 "$test_file" -o "$test_exe" 2>&1)
+    local basic_exit_code=$?
+
+    if [ $basic_exit_code -ne 0 ]; then
+        echo "  → Basic flags FAILED with exit code $basic_exit_code"
+        echo "  → Error output: $basic_result"
+        rm -f "$test_file" "$test_exe"
+        return 1
+    fi
+    echo "  → Basic flags: OK"
+    rm -f "$test_exe"
+
+    # Test reflection syntax
+    echo "  → Testing reflection syntax..."
+    cat > "$test_file" << 'EOF'
+struct Test {
+    int x;
+};
+
+int main() {
+    auto refl = ^^Test;
+    return 0;
+}
+EOF
+
+    local syntax_result=$("$compiler" -freflection -fexpansion-statements -std=c++26 "$test_file" -o "$test_exe" 2>&1)
+    local syntax_exit_code=$?
+
+    if [ $syntax_exit_code -eq 0 ]; then
+        echo "  → Reflection syntax: OK"
+        echo "  → ✓ REFLECTION SUPPORT CONFIRMED"
+        rm -f "$test_file" "$test_exe"
+        return 0
+    else
+        echo "  → Reflection syntax FAILED with exit code $syntax_exit_code"
+        echo "  → Error output: $syntax_result"
+        rm -f "$test_file" "$test_exe"
+        return 1
+    fi
+}
+
+# Find a compiler with reflection support
+echo "Searching for clang++ with reflection support..."
+
+REFLECTION_CXX=""
+REFLECTION_CC=""
+
+# List of potential clang++ locations to check
+POTENTIAL_COMPILERS=(
+    "/usr/local/bin/clang++"
+    "/opt/clang/bin/clang++"
+    "/usr/bin/clang++"
+    "clang++"
+)
+
+# If CXX is already set, test it first
+if [ -n "$CXX" ]; then
+    echo "Testing user-specified compiler: $CXX"
+    if test_reflection_support "$CXX"; then
+        REFLECTION_CXX="$CXX"
+        echo "✓ User-specified compiler supports reflection: $CXX"
+    else
+        echo "✗ User-specified compiler does not support reflection: $CXX"
+        echo "Will search for alternative..."
+    fi
+fi
+
+# If we don't have a working compiler yet, search for one
+if [ -z "$REFLECTION_CXX" ]; then
+    for compiler in "${POTENTIAL_COMPILERS[@]}"; do
+        echo "Testing: $compiler"
+        if test_reflection_support "$compiler"; then
+            REFLECTION_CXX="$compiler"
+            echo "✓ Found reflection-enabled compiler: $compiler"
+            break
+        else
+            echo "✗ No reflection support: $compiler"
+        fi
+    done
+fi
+
+# Check if we found a working compiler
+if [ -z "$REFLECTION_CXX" ]; then
+    echo
+    echo "╔════════════════════════════════════════════════════════════════════════════╗"
+    echo "║                                 ERROR                                      ║"
+    echo "╠════════════════════════════════════════════════════════════════════════════╣"
+    echo "║                                                                            ║"
+    echo "║ No clang++ compiler with reflection support found!                        ║"
+    echo "║                                                                            ║"
+    echo "║ This benchmark requires a compiler that supports C++26 reflection.        ║"
+    echo "║                                                                            ║"
+    echo "║ Options:                                                                   ║"
+    echo "║ 1. Use the Docker container: ./p2996/run_docker.sh                        ║"
+    echo "║ 2. Build clang with reflection from: https://github.com/bloomberg/clang-p2996 ║"
+    echo "║ 3. Set CXX environment variable to point to reflection-enabled clang++    ║"
+    echo "║                                                                            ║"
+    echo "║ Example: CXX=/path/to/reflection-clang++ ./benchmark_script.sh            ║"
+    echo "║                                                                            ║"
+    echo "╚════════════════════════════════════════════════════════════════════════════╝"
+    exit 1
+fi
+
+# Set the compilers
+export CXX="$REFLECTION_CXX"
+
+# Find corresponding C compiler
+if [ -n "$CC" ]; then
+    REFLECTION_CC="$CC"
+elif [ "$REFLECTION_CXX" = "/usr/local/bin/clang++" ]; then
+    REFLECTION_CC="/usr/local/bin/clang"
+elif [ "$REFLECTION_CXX" = "/opt/clang/bin/clang++" ]; then
+    REFLECTION_CC="/opt/clang/bin/clang"
+elif [ "$REFLECTION_CXX" = "/usr/bin/clang++" ]; then
+    REFLECTION_CC="/usr/bin/clang"
+else
+    REFLECTION_CC="clang"
+fi
+
+export CC="$REFLECTION_CC"
+
+echo
+echo "Using reflection-enabled compiler: $($CXX --version | head -n1)"
+echo "Using C compiler: $($CC --version | head -n1)"
+echo
+
+# Function to create manual parsing test
+create_manual_parsing_test() {
+    local test_name="$1"
+    local struct_complexity="$2"
+
+    cat > "${test_name}_manual.cpp" << 'EOF'
+#include <simdjson.h>
+#include <iostream>
+#include <string>
+#include <vector>
+#include <optional>
+
+// Test structures
+struct Person {
+    std::string name;
+    int age;
+    bool active;
+};
+
+struct Address {
+    std::string street;
+    std::string city;
+    int zipcode;
+};
+
+struct Employee {
+    Person person;
+    Address address;
+    std::vector<std::string> skills;
+    std::optional<std::string> department;
+    double salary;
+};
+
+// Manual parsing functions
+bool parse_person_manual(simdjson::ondemand::value& val, Person& person) {
+    auto obj = val.get_object();
+    if (obj.error()) return false;
+
+    for (auto field : obj) {
+        std::string_view key = field.unescaped_key();
+        if (key == "name") {
+            std::string_view name_val;
+            if (field.value().get(name_val)) return false;
+            person.name = name_val;
+        } else if (key == "age") {
+            if (field.value().get(person.age)) return false;
+        } else if (key == "active") {
+            if (field.value().get(person.active)) return false;
+        }
+    }
+    return true;
+}
+
+bool parse_address_manual(simdjson::ondemand::value& val, Address& address) {
+    auto obj = val.get_object();
+    if (obj.error()) return false;
+
+    for (auto field : obj) {
+        std::string_view key = field.unescaped_key();
+        if (key == "street") {
+            std::string_view street_val;
+            if (field.value().get(street_val)) return false;
+            address.street = street_val;
+        } else if (key == "city") {
+            std::string_view city_val;
+            if (field.value().get(city_val)) return false;
+            address.city = city_val;
+        } else if (key == "zipcode") {
+            if (field.value().get(address.zipcode)) return false;
+        }
+    }
+    return true;
+}
+
+bool parse_employee_manual(simdjson::ondemand::document& doc, Employee& employee) {
+    auto obj = doc.get_object();
+    if (obj.error()) return false;
+
+    for (auto field : obj) {
+        std::string_view key = field.unescaped_key();
+        if (key == "person") {
+            auto person_val = field.value();
+            if (!parse_person_manual(person_val, employee.person)) return false;
+        } else if (key == "address") {
+            auto addr_val = field.value();
+            if (!parse_address_manual(addr_val, employee.address)) return false;
+        } else if (key == "skills") {
+            auto skills_array = field.value().get_array();
+            if (skills_array.error()) return false;
+            for (auto skill : skills_array) {
+                std::string_view skill_val;
+                if (skill.get(skill_val)) return false;
+                employee.skills.emplace_back(skill_val);
+            }
+        } else if (key == "department") {
+            std::string_view dept_val;
+            if (!field.value().get(dept_val)) {
+                employee.department = dept_val;
+            }
+        } else if (key == "salary") {
+            if (field.value().get(employee.salary)) return false;
+        }
+    }
+    return true;
+}
+
+int main() {
+    simdjson::ondemand::parser parser;
+    std::string json_str = R"({
+        "person": {
+            "name": "John Doe",
+            "age": 30,
+            "active": true
+        },
+        "address": {
+            "street": "123 Main St",
+            "city": "Anytown",
+            "zipcode": 12345
+        },
+        "skills": ["C++", "JSON", "Programming"],
+        "department": "Engineering",
+        "salary": 85000.50
+    })";
+
+    simdjson::ondemand::document doc;
+    auto error = parser.iterate(simdjson::pad(json_str)).get(doc);
+    if (error) {
+        std::cerr << "Parse error" << std::endl;
+        return 1;
+    }
+
+    Employee employee;
+    if (!parse_employee_manual(doc, employee)) {
+        std::cerr << "Manual parsing failed" << std::endl;
+        return 1;
+    }
+
+    std::cout << "Manual parsing successful: " << employee.person.name
+              << ", age " << employee.person.age << std::endl;
+    return 0;
+}
+EOF
+}
+
+# Function to create reflection parsing test
+create_reflection_parsing_test() {
+    local test_name="$1"
+    local struct_complexity="$2"
+
+    cat > "${test_name}_reflection.cpp" << 'EOF'
+#include <simdjson.h>
+#include <iostream>
+#include <string>
+#include <vector>
+#include <optional>
+
+// Test structures (same as manual version)
+struct Person {
+    std::string name;
+    int age;
+    bool active;
+};
+
+struct Address {
+    std::string street;
+    std::string city;
+    int zipcode;
+};
+
+struct Employee {
+    Person person;
+    Address address;
+    std::vector<std::string> skills;
+    std::optional<std::string> department;
+    double salary;
+};
+
+int main() {
+    simdjson::ondemand::parser parser;
+    std::string json_str = R"({
+        "person": {
+            "name": "John Doe",
+            "age": 30,
+            "active": true
+        },
+        "address": {
+            "street": "123 Main St",
+            "city": "Anytown",
+            "zipcode": 12345
+        },
+        "skills": ["C++", "JSON", "Programming"],
+        "department": "Engineering",
+        "salary": 85000.50
+    })";
+
+    simdjson::ondemand::document doc;
+    auto error = parser.iterate(simdjson::pad(json_str)).get(doc);
+    if (error) {
+        std::cerr << "Parse error" << std::endl;
+        return 1;
+    }
+
+    // Use reflection-based automatic deserialization
+    Employee employee;
+    auto result = doc.get<Employee>();
+    if (result.error()) {
+        std::cerr << "Reflection parsing failed" << std::endl;
+        return 1;
+    }
+    employee = result.value();
+
+    std::cout << "Reflection parsing successful: " << employee.person.name
+              << ", age " << employee.person.age << std::endl;
+    return 0;
+}
+EOF
+}
+
+# Function to time compilation of parsing approach
+time_parsing_compilation() {
+    local description="$1"
+    local test_file="$2"
+    local use_reflection="$3"
+    local iteration="$4"
+
+    echo "[$iteration] $description"
+
+    # Clean build
+    rm -rf build_parsing_test
+    mkdir build_parsing_test
+    cd build_parsing_test
+
+    # Copy test file
+    cp "../$test_file" .
+
+    echo "  Configuring..."
+    if [ "$use_reflection" = "true" ]; then
+        cmake -DCMAKE_CXX_COMPILER="$CXX" \
+              -DSIMDJSON_DEVELOPER_MODE=ON \
+              -DSIMDJSON_STATIC_REFLECTION=ON \
+              -DBUILD_SHARED_LIBS=OFF \
+              ../.. >/dev/null 2>&1
+    else
+        cmake -DCMAKE_CXX_COMPILER="$CXX" \
+              -DSIMDJSON_DEVELOPER_MODE=ON \
+              -DSIMDJSON_STATIC_REFLECTION=OFF \
+              -DBUILD_SHARED_LIBS=OFF \
+              ../.. >/dev/null 2>&1
+    fi
+
+    echo "  Building simdjson..."
+    cmake --build . --target simdjson >/dev/null 2>&1
+
+    echo "  Compiling parsing test..."
+    # Time just the test compilation
+    start_time=$(date +%s.%N)
+
+    "$CXX" -std=c++17 -I../../include "$test_file" -L. -lsimdjson -o parsing_test >/dev/null 2>&1
+
+    end_time=$(date +%s.%N)
+
+    # Calculate time duration
+    time_taken=$(echo "$end_time $start_time" | awk '{printf "%.3f", $1 - $2}')
+    echo "  Completed in: ${time_taken}s"
+
+    cd ..
+    rm -rf build_parsing_test
+
+    echo "$time_taken"
+}
+
+# Create test files
+echo "Creating test files..."
+create_manual_parsing_test "complex" "complex"
+create_reflection_parsing_test "complex" "complex"
+
+# Arrays to store times
+times_manual=""
+times_reflection=""
+
+echo
+echo "=== MANUAL PARSING COMPILATION ==="
+echo "Testing traditional simdjson parsing with explicit .get() calls"
+echo
+
+for i in $(seq 1 $ITERATIONS); do
+    time_result=$(time_parsing_compilation "Compiling manual parsing test" "complex_manual.cpp" "false" "$i" | tail -n1)
+    times_manual="$times_manual $time_result"
+done
+
+echo
+echo "=== REFLECTION PARSING COMPILATION ==="
+echo "Testing automatic deserialization with doc.get<Struct>()"
+echo
+
+for i in $(seq 1 $ITERATIONS); do
+    time_result=$(time_parsing_compilation "Compiling reflection parsing test" "complex_reflection.cpp" "true" "$i" | tail -n1)
+    times_reflection="$times_reflection $time_result"
+done
+
+echo
+echo "╔════════════════════════════════════════════════════════════════════════════╗"
+echo "║           REFLECTION USAGE COMPILATION RESULTS                             ║"
+echo "╠════════════════════════════════════════════════════════════════════════════╣"
+echo "║                                                                            ║"
+echo "║ MANUAL PARSING (explicit .get() calls):                                    ║"
+count=1
+for t in $times_manual; do
+    if [[ "$t" =~ ^[0-9]+\.?[0-9]*$ ]]; then
+        line=$(printf "Run %2d: %7.3f seconds" "$count" "$t")
+        print_box_line "$line"
+        count=$((count + 1))
+    fi
+done
+echo "║                                                                            ║"
+echo "║ REFLECTION PARSING (automatic doc.get<Struct>()):                          ║"
+count=1
+for t in $times_reflection; do
+    if [[ "$t" =~ ^[0-9]+\.?[0-9]*$ ]]; then
+        line=$(printf "Run %2d: %7.3f seconds" "$count" "$t")
+        print_box_line "$line"
+        count=$((count + 1))
+    fi
+done
+echo "╚════════════════════════════════════════════════════════════════════════════╝"
+
+echo
+echo "╔════════════════════════════════════════════════════════════════════════════╗"
+echo "║                              ANALYSIS SUMMARY                              ║"
+echo "╠════════════════════════════════════════════════════════════════════════════╣"
+echo "║                                                                            ║"
+
+# Calculate averages and percentages - filter to only numeric values first
+manual_numbers=""
+reflection_numbers=""
+
+for t in $times_manual; do
+    if [[ "$t" =~ ^[0-9]+\.?[0-9]*$ ]]; then
+        manual_numbers="$manual_numbers $t"
+    fi
+done
+
+for t in $times_reflection; do
+    if [[ "$t" =~ ^[0-9]+\.?[0-9]*$ ]]; then
+        reflection_numbers="$reflection_numbers $t"
+    fi
+done
+
+if [ -n "$manual_numbers" ] && [ -n "$reflection_numbers" ]; then
+    manual_avg=$(echo "$manual_numbers" | awk '{sum=0; for(i=1;i<=NF;i++) sum+=$i; print sum/NF}')
+    reflection_avg=$(echo "$reflection_numbers" | awk '{sum=0; for(i=1;i<=NF;i++) sum+=$i; print sum/NF}')
+    overhead=$(echo "$reflection_avg $manual_avg" | awk '{printf "%.3f", $1 - $2}')
+
+    if [ $(echo "$manual_avg > 0" | awk '{print ($1 > 0)}') -eq 1 ]; then
+        percent=$(echo "$reflection_avg $manual_avg" | awk '{printf "%.1f", ($1 - $2) / $2 * 100}')
+    else
+        percent="0"
+    fi
+
+    print_box_line "MANUAL PARSING RESULTS:"
+    print_box_line "$(printf "Average compilation time: %.3fs" "$manual_avg")"
+    print_box_line ""
+    print_box_line "REFLECTION PARSING RESULTS:"
+    print_box_line "$(printf "Average compilation time: %.3fs" "$reflection_avg")"
+    print_box_line ""
+    print_box_line "REFLECTION OVERHEAD:"
+    print_box_line "$(printf "Additional time: %.3fs (%+.1f%%)" "$overhead" "$percent")"
+    print_box_line ""
+else
+    echo "║ ERROR: Could not extract valid timing data                                 ║"
+    echo "║ Manual times: $times_manual"
+    echo "║ Reflection times: $times_reflection"
+    echo "║                                                                            ║"
+fi
+
+echo "╠════════════════════════════════════════════════════════════════════════════╣"
+echo "║                              INTERPRETATION                                ║"
+echo "╠════════════════════════════════════════════════════════════════════════════╣"
+echo "║                                                                            ║"
+echo "║ WHAT THESE RESULTS SHOW:                                                   ║"
+echo "║                                                                            ║"
+echo "║ • COMPILE-TIME COST: How much longer reflection parsing takes to compile   ║"
+echo "║   - Higher % = more expensive template instantiation and codegen           ║"
+echo "║                                                                            ║"
+echo "║ • CODE GENERATION OVERHEAD: Reflection creates parsing code at compile     ║"
+echo "║   time, which requires more template processing than manual parsing        ║"
+echo "║                                                                            ║"
+echo "║ • DEVELOPER TRADE-OFF: Reflection provides automatic deserialization       ║"
+echo "║   but at the cost of increased compilation time                            ║"
+echo "║                                                                            ║"
+echo "║ EVALUATION:                                                                ║"
+echo "║ • Low overhead (0-20%): Reflection is compile-time efficient               ║"
+echo "║ • Medium overhead (20-50%): Noticeable but potentially acceptable          ║"
+echo "║ • High overhead (50%+): Significant compilation cost for reflection        ║"
+echo "║                                                                            ║"
+echo "║ REAL-WORLD IMPACT:                                                         ║"
+echo "║ • Small projects: Absolute time matters more than percentage               ║"
+echo "║ • Large projects: Percentage overhead compounds across many files          ║"
+echo "║ • CI/CD pipelines: Longer builds affect development velocity               ║"
+echo "║                                                                            ║"
+echo "╚════════════════════════════════════════════════════════════════════════════╝"
+
+# Clean up test files
+rm -f complex_manual.cpp complex_reflection.cpp
+
+echo
+echo "Completed at: $(date)"

benchmark/car_builder/CMakeLists.txt

@@ -0,0 +1,14 @@
+# Executable
+add_executable(benchmark_car_builder benchmark_car_builder.cpp)
+
+# Compile for C++20.
+target_compile_features(benchmark_car_builder PRIVATE cxx_std_20)
+
+# Check if -march=native is supported
+include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag("-march=native" SIMDJSON_SUPPORTS_MARCH_NATIVE)
+if(SIMDJSON_SUPPORTS_MARCH_NATIVE)
+  target_compile_options(benchmark_car_builder PRIVATE -march=native)
+endif()
+
+target_include_directories(benchmark_car_builder PRIVATE ${CMAKE_CURRENT_LIST_DIR}/..)

benchmark/car_builder/benchmark_car_builder.cpp

@@ -0,0 +1,127 @@
+#include "event_counter.h"
+#include <random>
+#include <vector>
+
+#include <simdjson.h>
+
+event_collector collector;
+
+struct Car {
+  std::string make;
+  std::string model;
+  int64_t year; // We deliberately do not include the tire pressure.
+};
+
+std::vector<Car> generate_random_cars(size_t count) {
+  static const std::vector<std::string> makes = {"Toyota", "Honda", "Ford",
+                                                 "BMW", "Mazda"};
+  static const std::vector<std::string> models = {"Camry", "Civic", "Focus",
+                                                  "320i", "3"};
+  static thread_local std::mt19937 rng{std::random_device{}()};
+  std::uniform_int_distribution<int> make_dist(0, makes.size() - 1);
+  std::uniform_int_distribution<int> model_dist(0, models.size() - 1);
+  std::uniform_int_distribution<int64_t> year_dist(2000, 2025);
+  std::uniform_real_distribution<double> pressure_dist(30.0, 45.0);
+
+  std::vector<Car> cars;
+  cars.reserve(count);
+  for (size_t i = 0; i < count; ++i) {
+    Car car;
+    car.make = makes[make_dist(rng)];
+    car.model = models[model_dist(rng)];
+    car.year = year_dist(rng);
+    cars.push_back(std::move(car));
+  }
+  return cars;
+}
+
+std::string_view serialize(simdjson::builder::string_builder &sb,
+                           const std::vector<Car> &cars) {
+  sb.clear();
+  sb.start_array();
+  for (const auto &car : cars) {
+    sb.start_object();
+    sb.append_key_value("make", car.make);
+    sb.append_comma();
+    sb.append_key_value("model", car.model);
+    sb.append_comma();
+    sb.append_key_value("year", car.year);
+    sb.end_object();
+  }
+  sb.end_array();
+  std::string_view result;
+  if (sb.view().get(result)) {
+    return ""; // unexpected (error)
+  }
+  return result;
+}
+
+double pretty_print(const std::string &name, size_t num_chars,
+                    std::pair<event_aggregate, size_t> result) {
+  const auto &agg = result.first;
+  size_t N = result.second;
+  num_chars *= N;
+  printf("%-40s : %8.2f ns %8.2f GB/s", name.c_str(),
+         agg.elapsed_ns() / num_chars, num_chars / agg.elapsed_ns());
+  if (collector.has_events()) {
+    printf(" %8.2f GHz %8.2f cycles/char %8.2f ins./char %8.2f i/c",
+           agg.cycles() / agg.elapsed_ns(), agg.cycles() / num_chars,
+           agg.instructions() / num_chars, agg.instructions() / agg.cycles());
+  }
+  printf("\n");
+  return num_chars / agg.elapsed_ns();
+}
+
+template <class function_type>
+std::pair<event_aggregate, size_t>
+bench(const function_type &&function, size_t min_repeat = 100,
+      size_t min_time_ns = 40'000'000, size_t max_repeat = 10000000) {
+  size_t N = min_repeat;
+  if (N == 0) {
+    N = 1;
+  }
+  event_aggregate warm_aggregate{};
+  for (size_t i = 0; i < N; i++) {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    collector.start();
+    function();
+    std::atomic_thread_fence(std::memory_order_release);
+    event_count allocate_count = collector.end();
+    warm_aggregate << allocate_count;
+    if ((i + 1 == N) && (warm_aggregate.total_elapsed_ns() < min_time_ns) &&
+        (N < max_repeat)) {
+      N *= 10;
+    }
+  }
+  event_aggregate aggregate{};
+  for (size_t i = 0; i < 10; i++) {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    collector.start();
+    for (size_t i = 0; i < N; i++) {
+      function();
+    }
+    std::atomic_thread_fence(std::memory_order_release);
+    event_count allocate_count = collector.end();
+    aggregate << allocate_count;
+  }
+  return {aggregate, N};
+}
+
+void run_benchmarks() {
+  std::vector<Car> source = generate_random_cars(100000);
+  simdjson::builder::string_builder sb;
+  size_t volume = serialize(sb, source).size();
+
+  pretty_print("string_builder", volume, bench([&source, &sb]() -> size_t {
+                 return serialize(sb, source).size();
+               }));
+}
+
+int main() {
+  for (size_t trial = 0; trial < 3; trial++) {
+    printf("Trial %zu:\n", trial + 1);
+    run_benchmarks();
+    printf("\n");
+  }
+  return EXIT_SUCCESS;
+}

benchmark/dom/parse_stream.cpp

@@ -25,12 +25,11 @@ int main(int argc, char *argv[]) {
     exit(1);
   }
   const char *filename = argv[1];
-  auto v = simdjson::padded_string::load(filename);
-  if (v.error()) {
+  simdjson::padded_string p;
+  if (simdjson::padded_string::load(filename).get(p)) {
     std::cerr << "Could not load the file " << filename << std::endl;
     return EXIT_FAILURE;
   }
-  const simdjson::padded_string& p = v.value_unsafe();
   if (test_baseline) {
     std::wclog << "Baseline: Getline + normal parse... " << std::endl;
     std::cout << "Gigabytes/second\t"

benchmark/event_counter.h

@@ -122,6 +122,7 @@ struct event_aggregate {
   }
 
   double elapsed_sec() const { return total.elapsed_sec() / iterations; }
+  double total_elapsed_ns() const { return total.elapsed_ns(); }
   double elapsed_ns() const { return total.elapsed_ns() / iterations; }
   double cycles() const { return total.cycles() / iterations; }
   double instructions() const { return total.instructions() / iterations; }

benchmark/from/CMakeLists.txt

@@ -0,0 +1,15 @@
+# Executable
+add_executable(from_benchmark from_benchmark.cpp)
+
+# Compile for C++20.
+if(CMAKE_CXX_STANDARD LESS 20)
+  target_compile_features(from_benchmark PRIVATE cxx_std_20)
+endif()
+# Check if -march=native is supported
+include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag("-march=native" SIMDJSON_SUPPORTS_MARCH_NATIVE)
+if(SIMDJSON_SUPPORTS_MARCH_NATIVE)
+  target_compile_options(from_benchmark PRIVATE -march=native)
+endif()
+
+target_include_directories(from_benchmark PRIVATE ${CMAKE_CURRENT_LIST_DIR}/..)

benchmark/from/benchmark_helpers.h

@@ -0,0 +1,77 @@
+#ifndef BENCHMARK_HELPERS_H
+#define BENCHMARK_HELPERS_H
+
+#include "event_counter.h"
+#include <atomic>
+
+event_collector collector;
+
+template <class function_type>
+std::pair<event_aggregate, size_t>
+bench(const function_type &&function, size_t min_repeat = 10,
+      size_t min_time_ns = 40'000'000, size_t max_repeat = 10000000) {
+  size_t N = min_repeat;
+  if (N == 0) {
+    N = 1;
+  }
+  event_aggregate warm_aggregate{};
+  for (size_t i = 0; i < N; i++) {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    collector.start();
+    function();
+    std::atomic_thread_fence(std::memory_order_release);
+    event_count allocate_count = collector.end();
+    warm_aggregate << allocate_count;
+    if ((i + 1 == N) && (warm_aggregate.total_elapsed_ns() < min_time_ns) &&
+        (N < max_repeat)) {
+      N *= 10;
+    }
+  }
+  event_aggregate aggregate{};
+  for (size_t i = 0; i < 10; i++) {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    collector.start();
+    for (size_t i = 0; i < N; i++) {
+      function();
+    }
+    std::atomic_thread_fence(std::memory_order_release);
+    event_count allocate_count = collector.end();
+    aggregate << allocate_count;
+  }
+  return {aggregate, N};
+}
+
+double pretty_print(const std::string &name, size_t num_chars,
+                    std::pair<event_aggregate, size_t> result) {
+  const auto &agg = result.first;
+  size_t N = result.second;
+  num_chars *= N;
+  printf("%-40s : %8.2f ns %8.2f GB/s", name.c_str(),
+         agg.elapsed_ns() / num_chars, num_chars / agg.elapsed_ns());
+  if (collector.has_events()) {
+    printf(" %8.2f GHz %8.2f cycles/char %8.2f ins./char %8.2f i/c",
+           agg.cycles() / agg.elapsed_ns(), agg.cycles() / num_chars,
+           agg.instructions() / num_chars, agg.instructions() / agg.cycles());
+  }
+  printf("\n");
+  return num_chars / agg.elapsed_ns();
+}
+
+double pretty_print_array(const std::string &name, size_t num_chars, size_t num_elements,
+                    std::pair<event_aggregate, size_t> result) {
+  const auto &agg = result.first;
+  size_t N = result.second;
+  num_chars *= N;
+  printf("%-40s : %8.2f ns/char %8.2f ns/value %8.2f GB/s", name.c_str(),
+         agg.elapsed_ns() / num_chars, agg.elapsed_ns() / num_elements, num_chars / agg.elapsed_ns());
+  if (collector.has_events()) {
+    printf(" %8.2f GHz %8.2f cycles/char %8.2f ins./char %8.2f ins./value %8.2f i/c",
+           agg.cycles() / agg.elapsed_ns(), agg.cycles() / num_chars,
+           agg.instructions() / num_chars, agg.instructions() / num_elements, agg.instructions() / agg.cycles());
+  }
+  printf("\n");
+  return num_chars / agg.elapsed_ns();
+}
+
+
+#endif

benchmark/from/car_helpers.h

@@ -0,0 +1,146 @@
+#ifndef CAR_HELPERS_H
+#define CAR_HELPERS_H
+
+#include <iomanip>
+#include <random>
+#include <sstream>
+#include <vector>
+
+#include <simdjson.h>
+
+struct Car {
+  std::string make;
+  std::string model;
+  int64_t year; // We deliberately do not include the tire pressure.
+};
+
+using namespace simdjson;
+
+std::string random_car_json() {
+  static const std::vector<std::string> makes = {"Toyota", "Honda", "Ford",
+                                                 "BMW", "Mazda"};
+  static const std::vector<std::string> models = {"Camry", "Civic", "Focus",
+                                                  "320i", "3"};
+  static thread_local std::mt19937 rng{std::random_device{}()};
+  std::uniform_int_distribution<int> make_dist(0, makes.size() - 1);
+  std::uniform_int_distribution<int> model_dist(0, models.size() - 1);
+  std::uniform_int_distribution<int> year_dist(2000, 2025);
+  std::uniform_real_distribution<double> pressure_dist(30.0, 45.0);
+
+  std::ostringstream oss;
+  oss << R"({ "make": ")" << makes[make_dist(rng)] << R"(", "model": ")"
+      << models[model_dist(rng)] << R"(",  "year": )" << year_dist(rng)
+      << R"(, "tire_pressure": [ )" << std::fixed << std::setprecision(1)
+      << pressure_dist(rng) << ", " << pressure_dist(rng) << R"( ] })";
+  return oss.str();
+}
+
+std::string generate_car_json_stream(size_t N) {
+  std::ostringstream oss;
+  for (size_t i = 0; i < N; ++i) {
+    oss << random_car_json();
+    oss << "\n";
+  }
+  return oss.str();
+}
+
+std::string generate_car_json_array(size_t N) {
+  std::ostringstream oss;
+  oss << "[\n";
+  for (size_t i = 0; i < N; ++i) {
+    oss << random_car_json();
+    if (i < N - 1) {
+      oss << ",";
+    }
+    oss << "\n";
+  }
+  oss << "]";
+  return oss.str();
+}
+
+// We want to maximize C++ portability, but this is not needed with static
+// reflection (C++26).
+template <>
+simdjson_inline simdjson_result<Car>
+simdjson::ondemand::document::get() & noexcept {
+  ondemand::object obj;
+  auto error = get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  Car car;
+  if ((error = obj["make"].get_string(car.make))) {
+    return error;
+  }
+  if ((error = obj["model"].get_string(car.model))) {
+    return error;
+  }
+  if ((error = obj["year"].get_int64().get(car.year))) {
+    return error;
+  }
+  return car;
+}
+
+template <>
+simdjson_inline simdjson_result<Car> simdjson::ondemand::value::get() noexcept {
+  ondemand::object obj;
+  auto error = get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  Car car;
+  if ((error = obj["make"].get_string(car.make))) {
+    return error;
+  }
+  if ((error = obj["model"].get_string(car.model))) {
+    return error;
+  }
+  if ((error = obj["year"].get_int64().get(car.year))) {
+    return error;
+  }
+  return car;
+}
+
+template <>
+simdjson_inline simdjson_result<Car>
+simdjson::ondemand::document_reference::get() & noexcept {
+  ondemand::object obj;
+  auto error = get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  Car car;
+  if ((error = obj["make"].get_string(car.make))) {
+    return error;
+  }
+  if ((error = obj["model"].get_string(car.model))) {
+    return error;
+  }
+  if ((error = obj["year"].get_int64().get(car.year))) {
+    return error;
+  }
+  return car;
+}
+
+template <>
+simdjson_inline simdjson_result<Car>
+simdjson::ondemand::document_reference::get() && noexcept {
+  ondemand::object obj;
+  auto error = get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  Car car;
+  if ((error = obj["make"].get_string(car.make))) {
+    return error;
+  }
+  if ((error = obj["model"].get_string(car.model))) {
+    return error;
+  }
+  if ((error = obj["year"].get_int64().get(car.year))) {
+    return error;
+  }
+  return car;
+}
+
+#endif

benchmark/from/from_benchmark.cpp

@@ -0,0 +1,132 @@
+// We are going to assume C++20.
+
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <simdjson.h>
+#include <string>
+
+#include "benchmark_helpers.h"
+#include "car_helpers.h"
+
+using namespace simdjson;
+
+void run_benchmarks() {
+  printf("Running benchmarks on tiny input...\n");
+  simdjson::padded_string json =
+      R"({ "make": "Toyota", "model": "Camry",  "year": 2018, "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  volatile size_t dummy = 0;
+  ondemand::parser parser;
+
+  // Classic On-Demand
+  pretty_print("simdjson classic", json.size(),
+               bench([&json, &dummy, &parser]() {
+                 ondemand::document doc = parser.iterate(json);
+                 Car car = doc.get<Car>();
+                 dummy = dummy + car.year;
+               }));
+
+  // Benchmark simdjson::from() without parser
+  pretty_print("simdjson::from<Car>() (no parser)", json.size(),
+               bench([&json, &dummy]() {
+                 Car car = simdjson::from(json);
+                 dummy = dummy + car.year;
+               }));
+
+  // Benchmark simdjson::from() with parser
+  pretty_print("simdjson::from<Car>() (with parser)", json.size(),
+               bench([&json, &dummy, &parser]() {
+                 Car car = simdjson::from(parser, json);
+                 dummy = dummy + car.year;
+               }));
+}
+
+void run_array_benchmarks() {
+  printf("Running benchmarks on large array...\n");
+  size_t N = 1'000'000;
+  simdjson::padded_string json = generate_car_json_array(N);
+  volatile size_t dummy = 0;
+  ondemand::parser parser;
+
+  // Classic On-Demand
+  pretty_print_array("simdjson classic", json.size(), N,
+                     bench([&json, &dummy, &parser]() {
+                       dummy = 0;
+                       ondemand::document doc = parser.iterate(json);
+                       ondemand::array array = doc.get_array();
+                       for (auto value : array) {
+                         Car car = value.get<Car>();
+                         dummy = dummy + car.year;
+                       }
+                     }));
+
+  // from with array
+  pretty_print_array("simdjson::from(json).array()", json.size(), N,
+                     bench([&json, &dummy, &parser]() {
+                       dummy = 0;
+
+                       for (auto value : simdjson::from(json).array()) {
+                         Car car = value.get<Car>();
+                         dummy = dummy + car.year;
+                       }
+                     }));
+#if SIMDJSON_SUPPORTS_RANGES_FROM
+  // Benchmark simdjson::from() without parser (EXPERIMENTAL)
+  pretty_print_array("simdjson::from<Car>() (experimental, no parser)",
+                     json.size(), N, bench([&json, &dummy]() {
+                       dummy = 0;
+                       for (Car car :
+                            simdjson::from(json) | simdjson::as<Car>()) {
+                         dummy = dummy + car.year;
+                       }
+                     }));
+
+  // Benchmark simdjson::from() with parser (EXPERIMENTAL)
+  pretty_print_array("simdjson::from<Car>() (experimental, with parser)",
+                     json.size(), N, bench([&json, &dummy, &parser]() {
+                       dummy = 0;
+                       for (Car car : simdjson::from(parser, json) |
+                                          simdjson::as<Car>()) {
+                         dummy = dummy + car.year;
+                       }
+                     }));
+#endif // SIMDJSON_SUPPORTS_RANGES_FROM
+}
+
+void run_stream_benchmarks() {
+  printf("Running stream benchmarks...\n");
+  simdjson::padded_string json = generate_car_json_stream(1'000'000);
+  volatile size_t dummy = 0;
+  ondemand::parser parser;
+
+  // Classic On-Demand
+  pretty_print("simdjson classic", json.size(),
+               bench([&json, &dummy, &parser]() {
+                 ondemand::document_stream stream = parser.iterate_many(json);
+                 for (auto doc : stream) {
+                   Car car = doc.get<Car>();
+                   dummy = dummy + car.year;
+                 }
+               }));
+  // from_many
+  pretty_print("simdjson with thread local", json.size(),
+               bench([&json, &dummy, &parser]() {
+                 ondemand::document_stream stream =
+                     ondemand::parser::get_parser().iterate_many(json);
+                 for (auto doc : stream) {
+                   Car car = doc.get<Car>();
+                   dummy = dummy + car.year;
+                 }
+               }));
+}
+
+int main() {
+  for (size_t trial = 0; trial < 3; trial++) {
+    printf("Trial %zu:\n", trial + 1);
+    run_array_benchmarks();
+    run_stream_benchmarks();
+    run_benchmarks();
+    printf("\n");
+  }
+  return EXIT_SUCCESS;
+}

benchmark/get_corpus_benchmark.cpp

@@ -9,7 +9,11 @@ simdjson_never_inline
 double bench(std::string filename, simdjson::padded_string& p) {
   std::chrono::time_point<std::chrono::steady_clock> start_clock =
       std::chrono::steady_clock::now();
-  simdjson::padded_string::load(filename).value_unsafe().swap(p);
+  auto error = simdjson::padded_string::load(filename).get(p);
+  if(error) {
+    std::cerr << simdjson::error_message(error) << std::endl;
+    std::abort();
+  }
   std::chrono::time_point<std::chrono::steady_clock> end_clock =
       std::chrono::steady_clock::now();
   std::chrono::duration<double> elapsed = end_clock - start_clock;

benchmark/large_random/simdjson_ondemand.h

@@ -23,7 +23,29 @@ struct simdjson_ondemand {
 };
 
 BENCHMARK_TEMPLATE(large_random, simdjson_ondemand)->UseManualTime();
+#if SIMDJSON_STATIC_REFLECTION
 
+struct simdjson_ondemand_static_reflect {
+  static constexpr diff_flags DiffFlags = diff_flags::NONE;
+
+  ondemand::parser parser{};
+
+  bool run(simdjson::padded_string &json, std::vector<point> &result) {
+    auto doc = parser.iterate(json);
+    if(auto e = doc.get_array().get<std::vector<point>>(result); e) { return false; }
+    // We can also do it like so:
+    //for (ondemand::object coord : doc) {
+    //  result.emplace_back(coord.get<point>());
+    //}
+    // It seems that doing the reflection is slower than doing the manual lookup.
+    // E.g., it is faster if we do result.emplace_back(coord["x"], coord["y"], coord["z"]);
+    return true;
+  }
+};
+BENCHMARK_TEMPLATE(large_random, simdjson_ondemand_static_reflect)->UseManualTime();
+
+
+#endif
 } // namespace large_random
 
 #endif // SIMDJSON_EXCEPTIONS

benchmark/static_reflect/CMakeLists.txt

@@ -0,0 +1,48 @@
+# Include reflect-cpp
+CPMAddPackage(
+  NAME reflect-cpp
+  GITHUB_REPOSITORY getml/reflect-cpp
+  GIT_TAG v0.17.0
+  EXCLUDE_FROM_ALL YES
+)
+
+option(SIMDJSON_USE_RUST "Build the static_reflect benchmark" OFF)
+
+if(SIMDJSON_USER_RUST)
+  if(NOT WIN32)
+  # We want the check whether Rust is available before trying to build a crate.
+  CPMAddPackage(
+    NAME corrosion
+    GITHUB_REPOSITORY corrosion-rs/corrosion
+    VERSION 0.4.4
+    DOWNLOAD_ONLY ON
+    OPTIONS "Rust_FIND_QUIETLY OFF"
+  )
+  include("${corrosion_SOURCE_DIR}/cmake/FindRust.cmake")
+  endif()
+
+  if(RUST_FOUND)
+    message(STATUS "Rust found: " ${Rust_VERSION} )
+    add_subdirectory("${corrosion_SOURCE_DIR}" "${PROJECT_BINARY_DIR}/_deps/corrosion" EXCLUDE_FROM_ALL)
+    # Important: we want to build in release mode!
+    corrosion_import_crate(MANIFEST_PATH "serde-benchmark/Cargo.toml" NO_LINKER_OVERRIDE PROFILE release)
+  else()
+    message(STATUS "Rust/Cargo is unavailable." )
+    message(STATUS "We will not benchmark serde-benchmark." )
+    if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+      message(STATUS "Under macOS, you may be able to install rust with")
+      message(STATUS "curl https://sh.rustup.rs -sSf | sh")
+    elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+      message(STATUS "Under Linux, you may be able to install rust with a command such as")
+      message(STATUS "apt-get install cargo" )
+      message(STATUS "or" )
+      message(STATUS "curl https://sh.rustup.rs -sSf | sh")
+    endif()
+  endif()
+else(SIMDJSON_USER_RUST)
+  message(STATUS "We will not benchmark serde-benchmark." )
+endif(SIMDJSON_USER_RUST)
+
+# Add the benchmark executable targets
+add_subdirectory(twitter_benchmark)
+add_subdirectory(citm_catalog_benchmark)

benchmark/static_reflect/benchmark_utils/benchmark_helper.h

@@ -0,0 +1,52 @@
+#ifndef BENCHMARK_HELPER_HPP
+#define BENCHMARK_HELPER_HPP
+#include "event_counter.h"
+#include <atomic>
+
+inline event_collector &get_collector() {
+  static event_collector collector;
+  return collector;
+}
+
+template <class function_type>
+event_aggregate bench(const function_type &function, size_t min_repeat = 10,
+                      size_t min_time_ns = 1000000000,
+                      size_t max_repeat = 100000) {
+  event_collector &collector = get_collector();
+  event_aggregate aggregate{};
+  size_t N = min_repeat;
+  if (N == 0) {
+    N = 1;
+  }
+  for (size_t i = 0; i < N; i++) {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    collector.start();
+    function();
+    std::atomic_thread_fence(std::memory_order_release);
+    event_count allocate_count = collector.end();
+    aggregate << allocate_count;
+    if ((i + 1 == N) && (aggregate.total_elapsed_ns() < min_time_ns) &&
+        (N < max_repeat)) {
+      N *= 10;
+    }
+  }
+  return aggregate;
+}
+
+// Source of the 2 functions below:
+// https://github.com/simdutf/simdutf/blob/master/benchmarks/base64/benchmark_base64.cpp
+inline void pretty_print(size_t strings, size_t bytes, std::string name,
+                         event_aggregate agg) {
+  event_collector &collector = get_collector();
+  printf("%-60s : ", name.c_str());
+  printf(" %5.2f MB/s ", bytes * 1000 / agg.elapsed_ns());
+  printf(" %5.2f Ms/s ", strings * 1000 / agg.elapsed_ns());
+  if (collector.has_events()) {
+    printf(" %5.2f GHz ", agg.cycles() / agg.elapsed_ns());
+    printf(" %5.2f c/b ", agg.cycles() / bytes);
+    printf(" %5.2f i/b ", agg.instructions() / bytes);
+    printf(" %5.2f i/c ", agg.instructions() / agg.cycles());
+  }
+  printf("\n");
+}
+#endif

benchmark/static_reflect/citm_catalog_benchmark/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_executable(benchmark_serialization_citm_catalog benchmark_serialization_citm_catalog.cpp)
+
+# Link with Rust benchmarking code if available
+if(TARGET serde-benchmark)
+    message(STATUS "serde-benchmark target was created. Linking CITM catalog benchmark with serde-benchmark.")
+    target_link_libraries(benchmark_serialization_citm_catalog PRIVATE serde-benchmark)
+    target_compile_definitions(benchmark_serialization_citm_catalog PRIVATE SIMDJSON_RUST_VERSION="${Rust_VERSION}")
+endif()
+
+target_link_libraries(benchmark_serialization_citm_catalog PRIVATE simdjson::simdjson nlohmann_json)
+target_link_libraries(benchmark_serialization_citm_catalog PRIVATE reflectcpp)
+target_compile_definitions(benchmark_serialization_citm_catalog PRIVATE SIMDJSON_BENCH_CPP_REFLECT=1)
+
+target_compile_definitions(benchmark_serialization_citm_catalog PRIVATE JSON_FILE="${BENCH_CITM_JSON}")

benchmark/static_reflect/citm_catalog_benchmark/benchmark_serialization_citm_catalog.cpp

@@ -0,0 +1,177 @@
+#include <cassert>
+#include <cstdlib>
+#include <ctime>
+#include <format>
+#include <fstream>
+#include <iostream>
+#include <nlohmann/json.hpp>
+#include <simdjson.h>
+#include <string>
+#include "citm_catalog_data.h"
+#include "nlohmann_citm_catalog_data.h"
+#include "../benchmark_utils/benchmark_helper.h"
+
+#if SIMDJSON_BENCH_CPP_REFLECT
+#include <rfl.hpp>
+#include <rfl/json.hpp>
+void bench_reflect_cpp(CitmCatalog &data) {
+  std::string output = rfl::json::write(data);
+  size_t output_volume = output.size();
+  printf("# output volume: %zu bytes\n", output_volume);
+
+  volatile size_t measured_volume = 0;
+  pretty_print(1, output_volume, "bench_reflect_cpp",
+               bench([&data, &measured_volume, &output_volume]() {
+                 std::string output = rfl::json::write(data);
+                 measured_volume = output.size();
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+               }));
+}
+#endif // SIMDJSON_BENCH_CPP_REFLECT
+
+#ifdef SIMDJSON_RUST_VERSION
+#include "../serde-benchmark/serde_benchmark.h"
+
+void bench_rust(serde_benchmark::CitmCatalog *data) {
+  const char * output = serde_benchmark::str_from_citm(data);
+  size_t output_volume = strlen(output);
+  printf("# output volume: %zu bytes\n", output_volume);
+  volatile size_t measured_volume = 0;
+  pretty_print(1, output_volume, "bench_rust",
+               bench([&data, &measured_volume, &output_volume]() {
+                 const char * output = serde_benchmark::str_from_citm(data);
+                 measured_volume = strlen(output);
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+                 serde_benchmark::free_str(const_cast<char*>(output));
+               }));
+  serde_benchmark::free_str(const_cast<char*>(output));
+}
+#endif // SIMDJSON_RUST_VERSION
+
+void bench_nlohmann(CitmCatalog &data) {
+  std::string output = nlohmann_serialize(data);
+  size_t output_volume = output.size();
+  printf("# output volume: %zu bytes\n", output_volume);
+
+  volatile size_t measured_volume = 0;
+  pretty_print(1, output_volume, "bench_nlohmann",
+               bench([&data, &measured_volume, &output_volume]() {
+                 std::string output = nlohmann_serialize(data);
+                 measured_volume = output.size();
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+               }));
+}
+
+void bench_simdjson_static_reflection(CitmCatalog &data) {
+  simdjson::builder::string_builder sb;
+  simdjson::builder::append(sb, data);
+  std::string_view p;
+  if(sb.view().get(p)) {
+    std::cerr << "Error!" << std::endl;
+  }
+  size_t output_volume = p.size();
+  sb.clear();
+  printf("# output volume: %zu bytes\n", output_volume);
+
+  volatile size_t measured_volume = 0;
+  pretty_print(sizeof(data), output_volume, "bench_simdjson_static_reflection",
+               bench([&data, &measured_volume, &output_volume, &sb]() {
+                 sb.clear();
+                 simdjson::builder::append(sb, data);
+                 std::string_view p;
+                 if(sb.view().get(p)) {
+                   std::cerr << "Error!" << std::endl;
+                 }
+                 measured_volume = sb.size();
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+               }));
+}
+
+std::string read_file(const std::string &file_path, size_t read_size = 65536) {
+  std::ifstream stream(file_path, std::ios::binary);
+  if(!stream) {
+    std::cerr << "Could not open file '" << file_path << "'" << std::endl;
+    exit(EXIT_FAILURE);
+  }
+  stream.exceptions(std::ios_base::badbit);
+  std::string out;
+  std::string buf(read_size, '\0');
+  while (stream.read(&buf[0], read_size)) {
+    out.append(buf, 0, size_t(stream.gcount()));
+  }
+  out.append(buf, 0, size_t(stream.gcount()));
+  return out;
+}
+
+// Function to check if benchmark name contains filter substring
+bool matches_filter(const std::string& benchmark_name, const std::string& filter) {
+  return filter.empty() || benchmark_name.find(filter) != std::string::npos;
+}
+
+int main(int argc, char* argv[]) {
+  std::string filter;
+
+  // Parse command-line arguments
+  for (int i = 1; i < argc; ++i) {
+      if (strcmp(argv[i], "-f") == 0 || strcmp(argv[i], "--filter") == 0) {
+          if (i + 1 < argc) {
+              filter = argv[++i];
+          } else {
+              std::cerr << "Error: -f/--filter requires an argument" << std::endl;
+              return EXIT_FAILURE;
+          }
+      }
+  }
+  // Testing correctness of round-trip (serialization + deserialization)
+  std::string json_str = read_file(JSON_FILE);
+
+  // Loading up the data into a structure.
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc;
+  if(parser.iterate(simdjson::pad(json_str)).get(doc)) {
+    std::cerr << "Error loading the document!" << std::endl;
+    return EXIT_FAILURE;
+  }
+  CitmCatalog my_struct;
+  if(doc.get<CitmCatalog>().get(my_struct)) {
+    std::cerr << "Error loading CitmCatalog!" << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  // Benchmarking the serialization
+  if (matches_filter("nlohmann", filter)) {
+    bench_nlohmann(my_struct);
+  }
+  if (matches_filter("simdjson_static_reflection", filter)) {
+    bench_simdjson_static_reflection(my_struct);
+  }
+#ifdef SIMDJSON_RUST_VERSION
+  if (matches_filter("rust", filter)) {
+    printf("# WARNING: The Rust benchmark may not be directly comparable since it does not use an equivalent data structure.\n");
+    // Create a Rust-compatible CitmCatalog structure from the JSON string
+    serde_benchmark::CitmCatalog* rust_data =
+      serde_benchmark::citm_from_str(json_str.c_str(), json_str.size());
+
+    if (rust_data == nullptr) {
+      printf("# Failed to initialize Rust data structure\n");
+    } else {
+      bench_rust(rust_data);
+      serde_benchmark::free_citm(rust_data);
+    }
+  }
+#endif
+#if SIMDJSON_BENCH_CPP_REFLECT
+  if (matches_filter("reflect_cpp", filter)) {
+    bench_reflect_cpp(my_struct);
+  }
+#endif
+  return EXIT_SUCCESS;
+}

benchmark/static_reflect/citm_catalog_benchmark/citm_catalog_data.h

@@ -0,0 +1,82 @@
+#ifndef CITM_CATALOG_DATA_H
+#define CITM_CATALOG_DATA_H
+
+#include <string>
+#include <vector>
+#include <map>
+
+struct Area {
+  int64_t id;
+  std::string name;
+  int64_t parent;
+  std::vector<int64_t> childAreas;
+  bool operator==(const Area &other) const = default;
+};
+
+struct AudienceSubCategory {
+  int64_t id;
+  std::string name;
+  int64_t parent;
+  bool operator==(const AudienceSubCategory &other) const = default;
+};
+
+struct Event {
+  int64_t id;
+  std::string name;
+  std::string description;
+  int64_t subTopic;
+  int64_t topic;
+  std::vector<int64_t> audience;
+  bool operator==(const Event &other) const = default;
+};
+
+struct Performance {
+  int64_t id;
+  std::string name;
+  int64_t event;
+  std::string start;
+  int64_t venueCode;
+  bool operator==(const Performance &other) const = default;
+};
+
+struct SeatCategory {
+  int64_t id;
+  std::string name;
+  std::vector<int64_t> areas;
+  bool operator==(const SeatCategory &other) const = default;
+};
+
+struct SubTopic {
+  int64_t id;
+  std::string name;
+  int64_t parent;
+  bool operator==(const SubTopic &other) const = default;
+};
+
+struct Topic {
+  int64_t id;
+  std::string name;
+  bool operator==(const Topic &other) const = default;
+};
+
+struct Venue {
+  int64_t id;
+  std::string name;
+  int64_t address;
+  bool operator==(const Venue &other) const = default;
+};
+
+struct CitmCatalog {
+  std::map<std::string, Area> areas;
+  std::map<std::string, AudienceSubCategory> audienceSubCategory;
+  std::map<std::string, Event> events;
+  std::map<std::string, Performance> performances;
+  std::map<std::string, SeatCategory> seatCategory;
+  std::map<std::string, SubTopic> subTopic;
+  std::map<std::string, Topic> topic;
+  std::map<std::string, Venue> venue;
+
+  bool operator==(const CitmCatalog &other) const = default;
+};
+
+#endif

benchmark/static_reflect/citm_catalog_benchmark/nlohmann_citm_catalog_data.h

@@ -0,0 +1,171 @@
+// nlohmann_citm_catalog_data.h
+#ifndef NLOHMANN_CITM_CATALOG_DATA_H
+#define NLOHMANN_CITM_CATALOG_DATA_H
+
+#include "citm_catalog_data.h"
+#include <nlohmann/json.hpp>
+#include <string>
+
+using json = nlohmann::json;
+
+// ---- Area ----
+inline void to_json(json &j, const Area &a) {
+    j = json{
+      {"id", a.id},
+      {"name", a.name},
+      {"parent", a.parent},
+      {"childAreas", a.childAreas}
+    };
+}
+inline void from_json(const json &j, Area &a) {
+    j.at("id").get_to(a.id);
+    j.at("name").get_to(a.name);
+    j.at("parent").get_to(a.parent);
+    j.at("childAreas").get_to(a.childAreas);
+}
+
+// ---- AudienceSubCategory ----
+inline void to_json(json &j, const AudienceSubCategory &asc) {
+    j = json{
+      {"id", asc.id},
+      {"name", asc.name},
+      {"parent", asc.parent}
+    };
+}
+inline void from_json(const json &j, AudienceSubCategory &asc) {
+    j.at("id").get_to(asc.id);
+    j.at("name").get_to(asc.name);
+    j.at("parent").get_to(asc.parent);
+}
+
+// ---- Event ----
+inline void to_json(json &j, const Event &e) {
+    j = json{
+      {"id", e.id},
+      {"name", e.name},
+      {"description", e.description},
+      {"subTopic", e.subTopic},
+      {"topic", e.topic},
+      {"audience", e.audience}
+    };
+}
+inline void from_json(const json &j, Event &e) {
+    j.at("id").get_to(e.id);
+    j.at("name").get_to(e.name);
+    j.at("description").get_to(e.description);
+    j.at("subTopic").get_to(e.subTopic);
+    j.at("topic").get_to(e.topic);
+    j.at("audience").get_to(e.audience);
+}
+
+// ---- Performance ----
+inline void to_json(json &j, const Performance &p) {
+    j = json{
+      {"id", p.id},
+      {"name", p.name},
+      {"event", p.event},
+      {"start", p.start},
+      {"venueCode", p.venueCode}
+    };
+}
+inline void from_json(const json &j, Performance &p) {
+    j.at("id").get_to(p.id);
+    j.at("name").get_to(p.name);
+    j.at("event").get_to(p.event);
+    j.at("start").get_to(p.start);
+    j.at("venueCode").get_to(p.venueCode);
+}
+
+// ---- SeatCategory ----
+inline void to_json(json &j, const SeatCategory &sc) {
+    j = json{
+      {"id", sc.id},
+      {"name", sc.name},
+      {"areas", sc.areas}
+    };
+}
+inline void from_json(const json &j, SeatCategory &sc) {
+    j.at("id").get_to(sc.id);
+    j.at("name").get_to(sc.name);
+    j.at("areas").get_to(sc.areas);
+}
+
+// ---- SubTopic ----
+inline void to_json(json &j, const SubTopic &st) {
+    j = json{
+      {"id", st.id},
+      {"name", st.name},
+      {"parent", st.parent}
+    };
+}
+inline void from_json(const json &j, SubTopic &st) {
+    j.at("id").get_to(st.id);
+    j.at("name").get_to(st.name);
+    j.at("parent").get_to(st.parent);
+}
+
+// ---- Topic ----
+inline void to_json(json &j, const Topic &t) {
+    j = json{
+      {"id", t.id},
+      {"name", t.name}
+    };
+}
+inline void from_json(const json &j, Topic &t) {
+    j.at("id").get_to(t.id);
+    j.at("name").get_to(t.name);
+}
+
+// ---- Venue ----
+inline void to_json(json &j, const Venue &v) {
+    j = json{
+      {"id", v.id},
+      {"name", v.name},
+      {"address", v.address}
+    };
+}
+inline void from_json(const json &j, Venue &v) {
+    j.at("id").get_to(v.id);
+    j.at("name").get_to(v.name);
+    j.at("address").get_to(v.address);
+}
+
+// ---- CitmCatalog ----
+inline void to_json(json &j, const CitmCatalog &c) {
+    j = json{
+      {"areas", c.areas},
+      {"audienceSubCategory", c.audienceSubCategory},
+      {"events", c.events},
+      {"performances", c.performances},
+      {"seatCategory", c.seatCategory},
+      {"subTopic", c.subTopic},
+      {"topic", c.topic},
+      {"venue", c.venue}
+    };
+}
+inline void from_json(const json &j, CitmCatalog &c) {
+    j.at("areas").get_to(c.areas);
+    j.at("audienceSubCategory").get_to(c.audienceSubCategory);
+    j.at("events").get_to(c.events);
+    j.at("performances").get_to(c.performances);
+    j.at("seatCategory").get_to(c.seatCategory);
+    j.at("subTopic").get_to(c.subTopic);
+    j.at("topic").get_to(c.topic);
+    j.at("venue").get_to(c.venue);
+}
+
+// Optional convenience functions for benchmarking
+inline std::string nlohmann_serialize(const CitmCatalog &catalog) {
+    json j = catalog;
+    return j.dump();
+}
+inline bool nlohmann_deserialize(const std::string &json_in, CitmCatalog &catalog) {
+    try {
+        catalog = json::parse(json_in);
+        return false; // success
+    } catch(...) {
+        return true;  // failure
+    }
+}
+
+#endif // NLOHMANN_CITM_CATALOG_DATA_H

benchmark/static_reflect/serde-benchmark/Cargo.lock

@@ -0,0 +1,103 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "itoa"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
+
+[[package]]
+name = "libc"
+version = "0.2.158"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3cb5ba0dc43242ce17de99c180e96db90b235b8a9fdc9543c96d2209116bd9f"
+
+[[package]]
+name = "serde"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "99fce0ffe7310761ca6bf9faf5115afbc19688edd00171d81b1bb1b116c63e09"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde-benchmark"
+version = "0.1.0"
+dependencies = [
+ "libc",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.209"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5831b979fd7b5439637af1752d535ff49f4860c0f341d1baeb6faf0f4242170"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.127"
+source = "registry+https://github.com/rust-lang/crates.io-index"
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+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+]
+
+[[package]]
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+version = "2.0.76"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "578e081a14e0cefc3279b0472138c513f37b41a08d5a3cca9b6e4e8ceb6cd525"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"

benchmark/static_reflect/serde-benchmark/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "serde-benchmark"
+version = "0.1.0"
+
+[lib]
+path = "lib.rs"
+crate-type = ["cdylib"]
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }
+libc = "0.2"
+serde_json = "1.0"
+
+[profile.release]
+opt-level = 3
+debug = false
+lto = true

benchmark/static_reflect/serde-benchmark/README.md

@@ -0,0 +1,18 @@
+## Rust Serde FFI
+
+This folder includes FFI bindings for rust/serde.
+
+### Links
+
+- https://github.com/eqrion/cbindgen/blob/master/docs.md
+- https://gist.github.com/zbraniecki/b251714d77ffebbc73c03447f2b2c69f
+- https://michael-f-bryan.github.io/rust-ffi-guide/setting_up.html
+
+### Building
+
+- Generating cbindgen output
+  - Install dependencies with `brew install cbindgen` or `apt-get install cbindgen` or `cargo install cbindgen` or the equivalent: we used `cargo install --version 0.23.0 cbindgen`.
+  - Go to the directory where this README.md file is located
+  - Generate with `cbindgen --config cbindgen.toml --crate serde-benchmark --output serde_benchmark.h`
+- Building
+  - Run with `cargo build --release`

benchmark/static_reflect/serde-benchmark/cbindgen.toml

@@ -0,0 +1,12 @@
+autogen_warning = "/* Warning, this file is autogenerated by cbindgen. Don't modify this manually. */"
+include_version = true
+braces = "SameLine"
+line_length = 100
+tab_width = 2
+language = "C++"
+namespaces = ["serde_benchmark"]
+include_guard = "serde_benchmark_ffi_h"
+
+[parse]
+parse_deps = true
+include = ["serde_json", "serde"]

benchmark/static_reflect/serde-benchmark/lib.rs

@@ -0,0 +1,482 @@
+extern crate serde;
+extern crate serde_json;
+extern crate libc;
+
+use libc::{c_char, size_t};
+use serde::{Serialize, Deserialize};
+use std::{collections::HashMap, ffi::CString, ptr, slice};
+use serde::de::{self, Deserializer};
+/******************************************************/
+/******************************************************/
+/**
+ * Warning: the C++ code may not generate the same JSON.
+ */
+ /******************************************************/
+ /******************************************************/
+
+// This has no equivalent in C++:
+#[derive(Serialize, Deserialize)]
+pub struct Metadata {
+    result_type: String,
+    iso_language_code: String,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct User {
+    id: i64,
+    id_str: String,
+    name: String,
+    screen_name: String,
+    location: String,
+    description: String,
+    // C++ does not have those:
+    // url: Option<String>,
+    //protected: bool,
+    //listed_count: i64,
+    //created_at: String,
+    //favourites_count: i64,
+    //utc_offset: Option<i64>,
+    //time_zone: Option<String>,
+    //geo_enabled: bool,
+    verified: bool,
+    followers_count: i64,
+    friends_count: i64,
+    statuses_count: i64,
+    // C++ does not have those:
+    //lang: String,
+    //profile_background_color: String,
+    //profile_background_image_url: String,
+    //profile_background_image_url_https: String,
+    //profile_background_tile: bool,
+    //profile_image_url: String,
+    //profile_image_url_https: String,
+    //profile_banner_url: Option<String>,
+    //profile_link_color: String,
+    //profile_sidebar_border_color: String,
+    //profile_sidebar_fill_color: String,
+    //profile_text_color: String,
+    //profile_use_background_image: bool,
+    //default_profile: bool,
+    //default_profile_image: bool,
+    //following: bool,
+    //follow_request_sent: bool,
+    //notifications: bool,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Hashtag {
+    text: String,
+
+    // C++ has those but D. Lemire does not know what they are, they don't appear in the JSON:
+    // int64_t indices_start;
+    // int64_t indices_end;
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Url {
+    url: String,
+    expanded_url: String,
+    display_url: String,
+    // C++ has those but D. Lemire does not know what they are, they don't appear in the JSON:
+    // int64_t indices_start;
+    // int64_t indices_end;
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct UserMention {
+    id: i64,
+    name: String,
+    screen_name: String,
+    // Not in the C++ equivalent:
+    //id_str: String,
+    //indices: Vec<i64>,
+    // C++ has those but D. Lemire does not know what they are, they don't appear in the JSON:
+    // int64_t indices_start;
+    // int64_t indices_end;
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Entities {
+    hashtags: Vec<Hashtag>,
+    urls: Vec<Url>,
+    user_mentions: Vec<UserMention>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Status {
+    created_at: String,
+    id: i64,
+    text: String,
+    user: User,
+    entities: Entities,
+    retweet_count: i64,
+    favorite_count: i64,
+    favorited: bool,
+    retweeted: bool,
+    // None of these are in the C++ equivalent:
+    /*
+    metadata: Metadata,
+    id_str: String,
+    source: String,
+    truncated: bool,
+    in_reply_to_status_id: Option<i64>,
+    in_reply_to_status_id_str: Option<String>,
+    in_reply_to_user_id: Option<i64>,
+    in_reply_to_user_id_str: Option<String>,
+    in_reply_to_screen_name: Option<String>,
+    geo: Option<String>,
+    coordinates: Option<String>,
+    place: Option<String>,
+    contributors: Option<String>,
+    lang: String,
+    */
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct TwitterData {
+    statuses: Vec<Status>,
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn  twitter_from_str(raw_input: *const c_char, raw_input_length: size_t) -> *mut TwitterData {
+  let input = std::str::from_utf8_unchecked(slice::from_raw_parts(raw_input as *const u8, raw_input_length));
+  match serde_json::from_str(&input) {
+    Ok(result) => Box::into_raw(Box::new(result)),
+    Err(_) => std::ptr::null_mut(),
+  }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn str_from_twitter(raw: *mut TwitterData) -> *const c_char {
+  let twitter_thing = { &*raw };
+  let serialized = serde_json::to_string(&twitter_thing).unwrap();
+  return std::ffi::CString::new(serialized.as_str()).unwrap().into_raw()
+}
+
+
+#[no_mangle]
+pub unsafe extern "C" fn free_twitter(raw: *mut TwitterData) {
+  if raw.is_null() {
+    return;
+  }
+
+  drop(Box::from_raw(raw))
+}
+
+
+#[no_mangle]
+pub unsafe extern fn free_string(ptr: *const c_char) {
+    let _ = std::ffi::CString::from_raw(ptr as *mut _);
+}
+
+// Functions associated with the CitmCatalog benchmark
+
+#[derive(Serialize, Deserialize)]
+pub struct Area {
+    pub id: i64,
+    pub name: Option<String>,  // Changed to Option
+    pub parent: i64,
+    #[serde(rename = "childAreas")]
+    pub child_areas: Vec<i64>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct AudienceSubCategory {
+    pub id: i64,
+    pub name: Option<String>,  // Changed to Option
+    pub parent: i64,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Event {
+    #[serde(default)]
+    pub description: Option<String>,
+    pub id: i64,
+    #[serde(default)]
+    pub logo: Option<String>,
+    #[serde(default)]
+    pub name: Option<String>,
+    #[serde(default)]
+    pub subTopicIds: Vec<i64>,
+    #[serde(default)]
+    pub subjectCode: Option<String>,
+    #[serde(default)]
+    pub subtitle: Option<String>,
+    #[serde(default)]
+    pub topicIds: Vec<i64>,
+    // Add a catch-all for any other fields
+    #[serde(flatten)]
+    pub extra: HashMap<String, serde_json::Value>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Performance {
+    #[serde(default)]
+    pub id: i64,
+
+    #[serde(default)]
+    pub name: Option<String>,
+
+    #[serde(default)]
+    pub event: i64,
+
+    // This is the key fix - accept any JSON value type for timestamps
+    // This allows both string dates and integer timestamps (line 3511)
+    #[serde(default)]
+    pub start: serde_json::Value,
+
+    #[serde(rename = "venueCode")]
+    pub venue_code: String,
+
+    // Add a catch-all for any other fields
+    #[serde(flatten)]
+    pub extra: HashMap<String, serde_json::Value>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct SeatCategory {
+    pub id: i64,
+    pub name: Option<String>,  // Changed to Option
+    pub areas: Vec<i64>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct SubTopic {
+    pub id: i64,
+    pub name: Option<String>,  // Changed to Option
+    pub parent: i64,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Topic {
+    pub id: i64,
+    pub name: Option<String>,  // Changed to Option
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Venue {
+    pub id: i64,
+    pub name: Option<String>,  // Changed to Option
+    pub address: i64,
+}
+
+// Custom deserializers
+fn deserialize_string_to_area<'de, D>(deserializer: D) -> Result<HashMap<String, Area>, D::Error>
+where D: Deserializer<'de> {
+    let string_map: HashMap<String, String> = HashMap::deserialize(deserializer)?;
+    let mut result = HashMap::new();
+
+    for (id, name) in string_map {
+        let id_num = id.parse::<i64>().unwrap_or(0);
+        result.insert(id.clone(), Area {
+            id: id_num,
+            name: Some(name),
+            parent: 0,
+            child_areas: Vec::new(),
+        });
+    }
+
+    Ok(result)
+}
+
+fn deserialize_string_to_audience_subcategory<'de, D>(deserializer: D) -> Result<HashMap<String, AudienceSubCategory>, D::Error>
+where D: Deserializer<'de> {
+    let string_map: HashMap<String, String> = HashMap::deserialize(deserializer)?;
+    let mut result = HashMap::new();
+
+    for (id, name) in string_map {
+        let id_num = id.parse::<i64>().unwrap_or(0);
+        result.insert(id.clone(), AudienceSubCategory {
+            id: id_num,
+            name: Some(name),
+            parent: 0,
+        });
+    }
+
+    Ok(result)
+}
+
+fn deserialize_string_to_seat_category<'de, D>(deserializer: D) -> Result<HashMap<String, SeatCategory>, D::Error>
+where D: Deserializer<'de> {
+    let string_map: HashMap<String, String> = HashMap::deserialize(deserializer)?;
+    let mut result = HashMap::new();
+
+    for (id, name) in string_map {
+        let id_num = id.parse::<i64>().unwrap_or(0);
+        result.insert(id.clone(), SeatCategory {
+            id: id_num,
+            name: Some(name),
+            areas: Vec::new(),
+        });
+    }
+
+    Ok(result)
+}
+
+fn deserialize_string_to_subtopic<'de, D>(deserializer: D) -> Result<HashMap<String, SubTopic>, D::Error>
+where D: Deserializer<'de> {
+    let string_map: HashMap<String, String> = HashMap::deserialize(deserializer)?;
+    let mut result = HashMap::new();
+
+    for (id, name) in string_map {
+        let id_num = id.parse::<i64>().unwrap_or(0);
+        result.insert(id.clone(), SubTopic {
+            id: id_num,
+            name: Some(name),
+            parent: 0,
+        });
+    }
+
+    Ok(result)
+}
+
+fn deserialize_string_to_topic<'de, D>(deserializer: D) -> Result<HashMap<String, Topic>, D::Error>
+where D: Deserializer<'de> {
+    let string_map: HashMap<String, String> = HashMap::deserialize(deserializer)?;
+    let mut result = HashMap::new();
+
+    for (id, name) in string_map {
+        let id_num = id.parse::<i64>().unwrap_or(0);
+        result.insert(id.clone(), Topic {
+            id: id_num,
+            name: Some(name),
+        });
+    }
+
+    Ok(result)
+}
+
+fn deserialize_string_to_venue<'de, D>(deserializer: D) -> Result<HashMap<String, Venue>, D::Error>
+where D: Deserializer<'de> {
+    let string_map: HashMap<String, String> = HashMap::deserialize(deserializer)?;
+    let mut result = HashMap::new();
+
+    for (id, name) in string_map {
+        result.insert(id.clone(), Venue {
+            id: 0,
+            name: Some(name),
+            address: 0,
+        });
+    }
+
+    Ok(result)
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct CitmCatalog {
+    #[serde(rename = "areaNames")]
+    pub area_names: HashMap<String, String>,
+
+    #[serde(rename = "audienceSubCategoryNames")]
+    pub audience_subcategory_names: HashMap<String, String>,
+
+    #[serde(default)]
+    #[serde(rename = "blockNames")]
+    pub block_names: HashMap<String, String>,
+
+    pub events: HashMap<String, Event>,
+
+    #[serde(default)]
+    pub performances: Vec<Performance>,
+
+    #[serde(rename = "seatCategoryNames")]
+    pub seat_category_names: HashMap<String, String>,
+
+    #[serde(rename = "subTopicNames")]
+    pub subtopic_names: HashMap<String, String>,
+
+    #[serde(default)]
+    #[serde(rename = "subjectNames")]
+    pub subject_names: HashMap<String, String>,
+
+    #[serde(rename = "topicNames")]
+    pub topic_names: HashMap<String, String>,
+
+    #[serde(rename = "topicSubTopics")]
+    pub topic_subtopics: HashMap<String, Vec<i64>>,
+
+    #[serde(rename = "venueNames")]
+    pub venue_names: HashMap<String, String>,
+
+    // Catch-all for other fields
+    #[serde(flatten)]
+    pub extra: HashMap<String, serde_json::Value>,
+}
+
+/// Creates a CitmCatalog from a JSON string (UTF-8 encoded).
+#[no_mangle]
+pub unsafe extern "C" fn citm_from_str(
+    raw_input: *const c_char,
+    raw_input_length: usize
+) -> *mut CitmCatalog {
+    if raw_input.is_null() {
+        eprintln!("Error: Input pointer is null");
+        return ptr::null_mut();
+    }
+
+    // Convert the raw pointer + length into a Rust slice
+    let bytes = slice::from_raw_parts(raw_input as *const u8, raw_input_length);
+    let input_str = match std::str::from_utf8(bytes) {
+        Ok(s) => s,
+        Err(e) => {
+            eprintln!("Error: Invalid UTF-8 string: {}", e);
+            return ptr::null_mut();
+        }
+    };
+
+    // Try deserializing the input string into CitmCatalog
+    match serde_json::from_str::<CitmCatalog>(input_str) {
+        Ok(catalog) => Box::into_raw(Box::new(catalog)),
+        Err(e) => {
+            eprintln!("Error deserializing JSON: {}", e);
+            eprintln!("JSON snippet (first 200 chars): {:.200}...", input_str);
+            ptr::null_mut()
+        }
+    }
+}
+
+/// Serializes a CitmCatalog into a JSON string (UTF-8).
+#[no_mangle]
+pub unsafe extern "C" fn str_from_citm(raw_catalog: *mut CitmCatalog) -> *mut c_char {
+    if raw_catalog.is_null() {
+        eprintln!("Error: Catalog pointer is null");
+        return ptr::null_mut();
+    }
+
+    // Fix: Actually serialize the catalog
+    let catalog = &*raw_catalog;
+
+    match serde_json::to_string(catalog) {
+        Ok(serialized) => {
+            match CString::new(serialized) {
+                Ok(cstr) => cstr.into_raw(),
+                Err(e) => {
+                    eprintln!("Error creating CString: {}", e);
+                    ptr::null_mut()
+                }
+            }
+        },
+        Err(e) => {
+            eprintln!("Error serializing catalog to JSON: {}", e);
+            ptr::null_mut()
+        }
+    }
+}
+
+/// Frees the CitmCatalog pointer.
+#[no_mangle]
+pub unsafe extern "C" fn free_citm(raw_catalog: *mut CitmCatalog) {
+    if !raw_catalog.is_null() {
+        drop(Box::from_raw(raw_catalog));
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn free_str(ptr: *mut c_char) {
+    if !ptr.is_null() {
+        unsafe {
+            // Convert back into a CString, which automatically frees the memory
+            let _ = CString::from_raw(ptr);
+        }
+    }
+}

benchmark/static_reflect/serde-benchmark/serde_benchmark.h

@@ -0,0 +1,45 @@
+#ifndef serde_benchmark_ffi_h
+#define serde_benchmark_ffi_h
+
+/* Generated with cbindgen:0.28.0 */
+
+/* Warning, this file is autogenerated by cbindgen. Don't modify this manually. */
+
+#include <cstdarg>
+#include <cstdint>
+#include <cstdlib>
+#include <ostream>
+#include <new>
+
+namespace serde_benchmark {
+
+struct CitmCatalog;
+
+struct TwitterData;
+
+extern "C" {
+
+TwitterData *twitter_from_str(const char *raw_input, size_t raw_input_length);
+
+const char *str_from_twitter(TwitterData *raw);
+
+void free_twitter(TwitterData *raw);
+
+void free_string(const char *ptr);
+
+/// Creates a CitmCatalog from a JSON string (UTF-8 encoded).
+CitmCatalog *citm_from_str(const char *raw_input, uintptr_t raw_input_length);
+
+/// Serializes a CitmCatalog into a JSON string (UTF-8).
+char *str_from_citm(CitmCatalog *raw_catalog);
+
+/// Frees the CitmCatalog pointer.
+void free_citm(CitmCatalog *raw_catalog);
+
+void free_str(char *ptr);
+
+}  // extern "C"
+
+}  // namespace serde_benchmark
+
+#endif  // serde_benchmark_ffi_h

benchmark/static_reflect/twitter_benchmark/CMakeLists.txt

@@ -0,0 +1,14 @@
+
+# Add executable targets
+add_executable(benchmark_serialization_twitter benchmark_serialization_twitter.cpp)
+
+ if(TARGET serde-benchmark)
+    message(STATUS "serde-benchmark target was created. Linking benchmarks and serde-benchmark.")
+    target_link_libraries(benchmark_serialization_twitter PRIVATE serde-benchmark)
+    target_compile_definitions(benchmark_serialization_twitter PRIVATE SIMDJSON_RUST_VERSION="${Rust_VERSION}")
+endif()
+target_link_libraries(benchmark_serialization_twitter PRIVATE simdjson::simdjson nlohmann_json)
+target_link_libraries(benchmark_serialization_twitter PRIVATE reflectcpp)
+target_compile_definitions(benchmark_serialization_twitter PRIVATE SIMDJSON_BENCH_CPP_REFLECT=1)
+
+target_compile_definitions(benchmark_serialization_twitter PRIVATE JSON_FILE="${EXAMPLE_JSON}")

benchmark/static_reflect/twitter_benchmark/benchmark_serialization_twitter.cpp

@@ -0,0 +1,168 @@
+#include <cassert>
+#include <cstdlib>
+#include <ctime>
+#include <format>
+#include <fstream>
+#include <iostream>
+#include <nlohmann/json.hpp>
+#include <simdjson.h>
+#include <string>
+#include "twitter_data.h"
+#include "nlohmann_twitter_data.h"
+#include "../benchmark_utils/benchmark_helper.h"
+#if SIMDJSON_BENCH_CPP_REFLECT
+#include <rfl.hpp>
+#include <rfl/json.hpp>
+void bench_reflect_cpp(TwitterData &data) {
+  std::string output = rfl::json::write(data);
+  size_t output_volume = output.size();
+  printf("# output volume: %zu bytes\n", output_volume);
+
+  volatile size_t measured_volume = 0;
+  pretty_print(1, output_volume, "bench_reflect_cpp",
+               bench([&data, &measured_volume, &output_volume]() {
+                 std::string output = rfl::json::write(data);
+                 measured_volume = output.size();
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+               }));
+}
+#endif // SIMDJSON_BENCH_CPP_REFLECT
+
+#ifdef SIMDJSON_RUST_VERSION
+#include "../serde-benchmark/serde_benchmark.h"
+
+
+void bench_rust(serde_benchmark::TwitterData *data) {
+  const char * output = serde_benchmark::str_from_twitter(data);
+  size_t output_volume = strlen(output);
+  printf("# output volume: %zu bytes\n", output_volume);
+  volatile size_t measured_volume = 0;
+  pretty_print(1, output_volume, "bench_rust",
+               bench([&data, &measured_volume, &output_volume]() {
+                 const char * output = serde_benchmark::str_from_twitter(data);
+                 serde_benchmark::free_string(output);
+               }));
+}
+#endif
+
+template <class T> void bench_simdjson_static_reflection(T &data) {
+  simdjson::builder::string_builder sb;
+  simdjson::builder::append(sb, data);
+  std::string_view p;
+  if(sb.view().get(p)) {
+    std::cerr << "Error!" << std::endl;
+  }
+  size_t output_volume = p.size();
+  sb.clear();
+  printf("# output volume: %zu bytes\n", output_volume);
+
+  volatile size_t measured_volume = 0;
+  pretty_print(sizeof(data), output_volume, "bench_simdjson_static_reflection",
+               bench([&data, &measured_volume, &output_volume, &sb]() {
+                 sb.clear();
+                 simdjson::builder::append(sb, data);
+                 std::string_view p;
+                 if(sb.view().get(p)) {
+                   std::cerr << "Error!" << std::endl;
+                 }
+                 measured_volume = sb.size();
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+               }));
+}
+
+void bench_nlohmann(TwitterData &data) {
+  std::string output = nlohmann_serialize(data);
+  size_t output_volume = output.size();
+  printf("# output volume: %zu bytes\n", output_volume);
+
+  volatile size_t measured_volume = 0;
+  pretty_print(1, output_volume, "bench_nlohmann",
+               bench([&data, &measured_volume, &output_volume]() {
+                 std::string output = nlohmann_serialize(data);
+                 measured_volume = output.size();
+                 if (measured_volume != output_volume) {
+                   printf("mismatch\n");
+                 }
+               }));
+}
+
+size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp) {
+  ((std::string *)userp)->append((char *)contents, size * nmemb);
+  return size * nmemb;
+}
+
+std::string read_file(std::string filename) {
+  printf("# Reading file %s\n", filename.c_str());
+  constexpr size_t read_size = 4096;
+  auto stream = std::ifstream(filename.c_str());
+  stream.exceptions(std::ios_base::badbit);
+  std::string out;
+  std::string buf(read_size, '\0');
+  while (stream.read(&buf[0], read_size)) {
+    out.append(buf, 0, size_t(stream.gcount()));
+  }
+  out.append(buf, 0, size_t(stream.gcount()));
+  return out;
+}
+
+// Function to check if benchmark name contains filter substring
+bool matches_filter(const std::string& benchmark_name, const std::string& filter) {
+  return filter.empty() || benchmark_name.find(filter) != std::string::npos;
+}
+
+int main(int argc, char* argv[]) {
+  std::string filter;
+
+  // Parse command-line arguments
+  for (int i = 1; i < argc; ++i) {
+      if (strcmp(argv[i], "-f") == 0 || strcmp(argv[i], "--filter") == 0) {
+          if (i + 1 < argc) {
+              filter = argv[++i];
+          } else {
+              std::cerr << "Error: -f/--filter requires an argument" << std::endl;
+              return EXIT_FAILURE;
+          }
+      }
+  }
+  // Testing correctness of round-trip (serialization + deserialization)
+  std::string json_str = read_file(JSON_FILE);
+
+  // Loading up the data into a structure.
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc;
+  if(parser.iterate(simdjson::pad(json_str)).get(doc)) {
+    std::cerr << "Error loading the document!" << std::endl;
+    return EXIT_FAILURE;
+  }
+  TwitterData my_struct;
+  if(doc.get<TwitterData>().get(my_struct)) {
+    std::cerr << "Error loading TwitterData!" << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  // Benchmarking the serialization
+  if (matches_filter("nlohmann", filter)) {
+    bench_nlohmann(my_struct);
+  }
+  if (matches_filter("simdjson_static_reflection", filter)) {
+    bench_simdjson_static_reflection(my_struct);
+  }
+#ifdef SIMDJSON_RUST_VERSION
+  if (matches_filter("rust", filter)) {
+    printf("# WARNING: The Rust benchmark may not be directly comparable since it does not use an equivalent data structure.\n");
+    serde_benchmark::TwitterData * td = serde_benchmark::twitter_from_str(json_str.c_str(), json_str.size());
+    bench_rust(td);
+    serde_benchmark::free_twitter(td);
+  }
+#endif
+#if SIMDJSON_BENCH_CPP_REFLECT
+  if (matches_filter("reflect_cpp", filter)) {
+    bench_reflect_cpp(my_struct);
+  }
+#endif
+  return EXIT_SUCCESS;
+}

benchmark/static_reflect/twitter_benchmark/nlohmann_twitter_data.h

@@ -0,0 +1,116 @@
+#ifndef NLOHMANN_TWITTER_DATA_H
+#define NLOHMANN_TWITTER_DATA_H
+
+#include "twitter_data.h"
+#include <nlohmann/json.hpp>
+
+void to_json(nlohmann::json &j, const User &u) {
+  j = nlohmann::json{{"id", u.id},
+                     {"name", u.name},
+                     {"screen_name", u.screen_name},
+                     {"location", u.location},
+                     {"description", u.description},
+                     {"verified", u.verified},
+                     {"followers_count", u.followers_count},
+                     {"friends_count", u.friends_count},
+                     {"statuses_count", u.statuses_count}};
+}
+
+void to_json(nlohmann::json &j, const Hashtag &h) {
+  j = nlohmann::json{{"text", h.text},
+                     {"indices_start", h.indices_start},
+                     {"indices_end", h.indices_end}};
+}
+
+void to_json(nlohmann::json &j, const Url &u) {
+  j = nlohmann::json{{"url", u.url},
+                     {"expanded_url", u.expanded_url},
+                     {"display_url", u.display_url},
+                     {"indices_start", u.indices_start},
+                     {"indices_end", u.indices_end}};
+}
+
+void to_json(nlohmann::json &j, const UserMention &um) {
+  j = nlohmann::json{{"id", um.id},
+                     {"name", um.name},
+                     {"screen_name", um.screen_name},
+                     {"indices_start", um.indices_start},
+                     {"indices_end", um.indices_end}};
+}
+
+void to_json(nlohmann::json &j, const Entities &e) {
+  j = nlohmann::json{{"hashtags", e.hashtags},
+                     {"urls", e.urls},
+                     {"user_mentions", e.user_mentions}};
+}
+
+void to_json(nlohmann::json &j, const Status &s) {
+  j = nlohmann::json{{"created_at", s.created_at},
+                     {"id", s.id},
+                     {"text", s.text},
+                     {"user", s.user},
+                     {"entities", s.entities},
+                     {"retweet_count", s.retweet_count},
+                     {"favorite_count", s.favorite_count},
+                     {"favorited", s.favorited},
+                     {"retweeted", s.retweeted}};
+}
+
+
+std::string nlohmann_serialize(const std::vector<Hashtag>& v) {
+  nlohmann::json a = nlohmann::json::array();
+  for(const Hashtag & h : v) {
+    a.push_back(nlohmann::json{{"text", h.text},
+                     {"indices_start", h.indices_start},
+                     {"indices_end", h.indices_end}});
+  }
+  return a.dump();
+}
+std::string nlohmann_serialize(const std::vector<Url>& v) {
+  nlohmann::json a = nlohmann::json::array();
+  for(const Url & u : v) {
+    a.push_back(nlohmann::json{{"url", u.url},
+                     {"expanded_url", u.expanded_url},
+                     {"display_url", u.display_url},
+                     {"indices_start", u.indices_start},
+                     {"indices_end", u.indices_end}});
+  }
+  return a.dump();
+}
+std::string nlohmann_serialize(const std::vector<UserMention>& v) {
+  nlohmann::json a = nlohmann::json::array();
+  for(const UserMention & um : v) {
+    a.push_back(nlohmann::json{{"id", um.id},
+                     {"name", um.name},
+                     {"screen_name", um.screen_name},
+                     {"indices_start", um.indices_start},
+                     {"indices_end", um.indices_end}});
+  }
+  return a.dump();
+}
+
+std::string nlohmann_serialize(const std::vector<Status>& v) {
+  nlohmann::json a = nlohmann::json::array();
+  for(const Status & s : v) {
+    a.push_back(nlohmann::json{{"created_at", s.created_at},
+                     {"id", s.id},
+                     {"text", s.text},
+                     {"user", s.user},
+                     {"entities", s.entities},
+                     {"retweet_count", s.retweet_count},
+                     {"favorite_count", s.favorite_count},
+                     {"favorited", s.favorited},
+                     {"retweeted", s.retweeted}});
+  }
+  return a.dump();
+}
+
+void to_json(nlohmann::json &j, const TwitterData &t) {
+  j = nlohmann::json{{"statuses", t.statuses}};
+}
+
+std::string nlohmann_serialize(const TwitterData &data) {
+  return nlohmann_serialize(data.statuses);
+}
+
+#endif // NLOHMANN_TWITTER_DATA_H

benchmark/static_reflect/twitter_benchmark/twitter_data.h

@@ -0,0 +1,71 @@
+#ifndef TWITTER_DATA_H
+#define TWITTER_DATA_H
+
+#include <string>
+#include <vector>
+
+struct User {
+  int64_t id;
+  std::string id_str;
+  std::string name;
+  std::string screen_name;
+  std::string location;
+  std::string description;
+  bool verified;
+  int64_t followers_count;
+  int64_t friends_count;
+  int64_t statuses_count;
+  bool operator<=>(const User &other) const = default;
+};
+
+struct Hashtag {
+  std::string text;
+  int64_t indices_start;
+  int64_t indices_end;
+  bool operator<=>(const Hashtag &other) const = default;
+};
+
+struct Url {
+  std::string url;
+  std::string expanded_url;
+  std::string display_url;
+  int64_t indices_start;
+  int64_t indices_end;
+  bool operator<=>(const Url &other) const = default;
+};
+
+struct UserMention {
+  int64_t id;
+  std::string name;
+  std::string screen_name;
+  int64_t indices_start;
+  int64_t indices_end;
+  bool operator<=>(const UserMention &other) const = default;
+};
+
+struct Entities {
+  std::vector<Hashtag> hashtags;
+  std::vector<Url> urls;
+  std::vector<UserMention> user_mentions;
+  bool operator==(const Entities &other) const = default;
+};
+
+struct Status {
+  std::string created_at;
+  int64_t id;
+  std::string text;
+  User user;
+  Entities entities;
+  int64_t retweet_count;
+  int64_t favorite_count;
+  bool favorited;
+  bool retweeted;
+  bool operator==(const Status &other) const = default;
+};
+
+struct TwitterData {
+  std::vector<Status> statuses;
+  bool operator==(const TwitterData &other) const = default;
+};
+
+#endif

cmake/developer-options.cmake

@@ -2,7 +2,10 @@
 # Flags used by exes and by the simdjson library (project-wide flags)
 #
 add_library(simdjson-internal-flags INTERFACE)
-
+if(NOT DEFINED CMAKE_POSITION_INDEPENDENT_CODE)
+  # We default to ON for all targets, so that we can use the library in shared libraries.
+  set_target_properties(simdjson-internal-flags PROPERTIES INTERFACE_POSITION_INDEPENDENT_CODE ON)
+endif(NOT DEFINED CMAKE_POSITION_INDEPENDENT_CODE)
 
 option(SIMDJSON_CHECK_EOF "Check for the end of the input buffer. The setting is unnecessary since we require padding of the inputs. You should expect tests to fail with this option turned on." OFF)
 if(SIMDJSON_CHECK_EOF)
@@ -29,6 +32,9 @@ undefined behavior.")
     link_libraries(
         -fsanitize=address -fno-omit-frame-pointer -fno-sanitize-recover=all
     )
+  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+    add_compile_options(-fsanitize=address)
+    link_libraries(-fsanitize=address)
   else()
     message(
         STATUS
@@ -52,7 +58,6 @@ endif()
 
 option(SIMDJSON_SANITIZE_MEMORY "Sanitize memory" OFF)
 
-
 if(SIMDJSON_SANITIZE_MEMORY)
   message(STATUS "Setting the memory sanitizer.")
   add_compile_options(
@@ -110,8 +115,14 @@ endif()
 
 # We compile tools, tests, etc. with C++ 17. Override yourself if you need on a
 # target.
-set(SIMDJSON_CXX_STANDARD 17 CACHE STRING "the C++ standard to use for simdjson")
-set(CMAKE_CXX_STANDARD ${SIMDJSON_CXX_STANDARD})
+if(SIMDJSON_STATIC_REFLECTION)
+  # This is temporary.
+  set(SIMDJSON_CXX_STANDARD 26 CACHE STRING "the C++ standard to use for simdjson")
+  #set(CMAKE_CXX_STANDARD ${SIMDJSON_CXX_STANDARD})
+else()
+  set(SIMDJSON_CXX_STANDARD 17 CACHE STRING "the C++ standard to use for simdjson")
+  set(CMAKE_CXX_STANDARD ${SIMDJSON_CXX_STANDARD})
+endif()
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_THREAD_PREFER_PTHREAD ON)
@@ -158,14 +169,15 @@ We recommend Visual Studio 2019 or better on a 64-bit system.")
     add_compile_options(/Zi)
   endif()
 else()
-  if(NOT WIN32)
-    target_compile_options(simdjson-internal-flags INTERFACE -fPIC)
-  endif()
   target_compile_options(
       simdjson-internal-flags INTERFACE
       -Werror -Wall -Wextra -Weffc++ -Wsign-compare -Wshadow -Wwrite-strings
       -Wpointer-arith -Winit-self -Wconversion -Wno-sign-conversion
   )
+  if(CMAKE_CXX_STANDARD VERSION_GREATER_EQUAL 20)
+    target_compile_options(simdjson-internal-flags INTERFACE -Wctad-maybe-unsupported)
+  endif()
+
 endif()
 
 option(SIMDJSON_GLIBCXX_ASSERTIONS "Set _GLIBCXX_ASSERTIONS" OFF)

cmake/toolchains-ci/riscv64-linux-gnu.cmake

@@ -0,0 +1,4 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR riscv64)
+
+set(CMAKE_CROSSCOMPILING_EMULATOR "qemu-riscv64-static")

dependencies/CMakeLists.txt

@@ -7,12 +7,12 @@ option(SIMDJSON_ALLOW_DOWNLOADS
 cmake_dependent_option(SIMDJSON_COMPETITION "Compile competitive benchmarks" ON
         SIMDJSON_ALLOW_DOWNLOADS OFF)
 cmake_dependent_option(SIMDJSON_GOOGLE_BENCHMARKS "compile the Google Benchmark benchmarks" ON
-        SIMDJSON_ALLOW_DOWNLOADS OFF)
+        "SIMDJSON_ALLOW_DOWNLOADS OR MINGW" OFF)
 
 if(SIMDJSON_GOOGLE_BENCHMARKS)
   CPMAddPackage(
         NAME google_benchmarks
-        URL https://github.com/google/benchmark/archive/refs/tags/v1.7.1.zip
+        URL https://github.com/google/benchmark/archive/refs/tags/v1.9.4.zip
         OPTIONS
         "BENCHMARK_ENABLE_TESTING OFF"
         "BENCHMARK_ENABLE_INSTALL OFF"
@@ -22,7 +22,7 @@ endif()
 
 CPMAddPackage(
         NAME simdjson-data
-        URL https://github.com/simdjson/simdjson-data/archive/a5b13babe65c1bba7186b41b43d4cbdc20a5c470.zip
+        URL https://github.com/simdjson/simdjson-data/archive/351949906abde446f0314bf79606fb5d884f5be7.zip
 )
 
 option(SIMDJSON_USE_BOOST_JSON "Try to include BOOST_JSON, this may break your binaries under some systems." OFF)
@@ -93,19 +93,11 @@ int main() {}
 
   CPMAddPackage(
       NAME nlohmann_json
-      URL https://github.com/nlohmann/json/archive/refs/tags/v3.10.5.zip
+      URL https://github.com/nlohmann/json/archive/refs/tags/v3.12.0.zip
   )
 
   set_property(TARGET nlohmann_json APPEND PROPERTY INTERFACE_COMPILE_DEFINITIONS SIMDJSON_COMPETITION_NLOHMANN_JSON)
 
-  CPMAddPackage(
-      NAME json11
-      URL https://github.com/dropbox/json11/archive/ec4e45219af1d7cde3d58b49ed762376fccf1ace.zip
-      DOWNLOAD_ONLY YES
-  )
-  add_library(json11 STATIC "${json11_SOURCE_DIR}/json11.cpp")
-  target_include_directories(json11 SYSTEM PUBLIC "${json11_SOURCE_DIR}")
-  target_compile_definitions(json11 INTERFACE SIMDJSON_COMPETITION_JSON11)
 
   set(jsoncpp_SOURCE_DIR "${simdjson_SOURCE_DIR}/dependencies/jsoncppdist")
   add_library(jsoncpp STATIC "${jsoncpp_SOURCE_DIR}/jsoncpp.cpp")
@@ -114,7 +106,7 @@ int main() {}
 
   CPMAddPackage(
       NAME rapidjson
-      URL https://github.com/Tencent/rapidjson/archive/f54b0e47a08782a6131cc3d60f94d038fa6e0a51.zip
+      URL https://github.com/Tencent/rapidjson/archive/805d7ed5dfe97a39b8b0816fd5eeed8731dc4936.zip
       DOWNLOAD_ONLY YES
   )
   add_library(rapidjson INTERFACE)
@@ -177,7 +169,7 @@ int main() {}
   endif()
 
   add_library(competition-all INTERFACE)
-  target_link_libraries(competition-all INTERFACE competition-core jsoncpp json11 fastjson gason ujson4c)
+  target_link_libraries(competition-all INTERFACE competition-core jsoncpp fastjson gason ujson4c)
 endfunction()
 
 if(SIMDJSON_COMPETITION)

doc/basics.md

@@ -1,59 +1,64 @@
 The Basics
 ==========
 
-An overview of what you need to know to use simdjson, with examples.
-
-- [The Basics](#the-basics)
-  - [Requirements](#requirements)
-  - [Including simdjson](#including-simdjson)
-  - [Using simdjson with package managers](#using-simdjson-with-package-managers)
-  - [Using simdjson as a CMake dependency](#using-simdjson-as-a-cmake-dependency)
-  - [Versions](#versions)
-  - [The basics: loading and parsing JSON documents](#the-basics-loading-and-parsing-json-documents)
-  - [Documents are iterators](#documents-are-iterators)
-    - [Parser, document and JSON scope](#parser-document-and-json-scope)
-  - [string_view](#string_view)
-  - [Avoiding pitfalls: enable development checks](#avoiding-pitfalls-enable-development-checks)
-  - [Using the parsed JSON](#using-the-parsed-json)
-    - [Using the parsed JSON: additional examples](#using-the-parsed-json-additional-examples)
-  - [Adding support for custom types](#adding-support-for-custom-types)
-    - [1. Specialize `simdjson::ondemand::value::get` to get custom types (pre-C++20)](#1-specialize-simdjsonondemandvalueget-to-get-custom-types-pre-c20)
-    - [2. Use `tag_invoke` for custom types (C++20)](#2-use-tag_invoke-for-custom-types-c20)
-  - [Minifying JSON strings without parsing](#minifying-json-strings-without-parsing)
-  - [UTF-8 validation (alone)](#utf-8-validation-alone)
-  - [JSON Pointer](#json-pointer)
-  - [JSONPath](#jsonpath)
-  - [Error handling](#error-handling)
-    - [Error handling examples without exceptions](#error-handling-examples-without-exceptions)
-    - [Disabling exceptions](#disabling-exceptions)
-    - [Exceptions](#exceptions)
-    - [Current location in document](#current-location-in-document)
-    - [Checking for trailing content](#checking-for-trailing-content)
-  - [Rewinding](#rewinding)
-  - [Newline-Delimited JSON (ndjson) and JSON lines](#newline-delimited-json-ndjson-and-json-lines)
-  - [Parsing numbers inside strings](#parsing-numbers-inside-strings)
-  - [Dynamic Number Types](#dynamic-number-types)
-  - [Raw strings from keys](#raw-strings-from-keys)
-  - [General direct access to the raw JSON string](#general-direct-access-to-the-raw-json-string)
-  - [Storing directly into an existing string instance](#storing-directly-into-an-existing-string-instance)
-  - [Thread safety](#thread-safety)
-  - [Standard compliance](#standard-compliance)
-  - [Backwards compatibility](#backwards-compatibility)
-  - [Examples](#examples)
-  - [Performance tips](#performance-tips)
-  - [Further reading](#further-reading)
+An overview of what you need to know to use simdjson to parse JSON documents, with examples.
+[Our documentation regarding the generation (serialization) of JSON documents is in a
+separate document](https://github.com/simdjson/simdjson/blob/master/doc/builder.md).
 
+- [Requirements](#requirements)
+- [Including simdjson](#including-simdjson)
+- [Using simdjson with package managers](#using-simdjson-with-package-managers)
+- [Using simdjson as a CMake dependency](#using-simdjson-as-a-cmake-dependency)
+- [Versions](#versions)
+- [The basics: loading and parsing JSON documents](#the-basics-loading-and-parsing-json-documents)
+- [Documents are iterators](#documents-are-iterators)
+  * [Parser, document and JSON scope](#parser-document-and-json-scope)
+- [string_view](#string_view)
+- [Avoiding pitfalls: enable development checks](#avoiding-pitfalls-enable-development-checks)
+- [Using the parsed JSON](#using-the-parsed-json)
+  * [Using the parsed JSON: additional examples](#using-the-parsed-json-additional-examples)
+- [Adding support for custom types](#adding-support-for-custom-types)
+  * [1. Specialize `simdjson::ondemand::value::get` to get custom types (pre-C++20)](#1-specialize-simdjsonondemandvalueget-to-get-custom-types-pre-c20)
+  * [2. Use `tag_invoke` for custom types (C++20)](#2-use-tag_invoke-for-custom-types-c20)
+  * [3. Using static reflection (C++26)](#3-using-static-reflection-c26)
+  * [The simdjson::from shortcut (experimental, C++20)](#the-simdjsonfrom-shortcut-experimental-c20)
+- [Minifying JSON strings without parsing](#minifying-json-strings-without-parsing)
+- [UTF-8 validation (alone)](#utf-8-validation-alone)
+- [JSON Pointer](#json-pointer)
+- [JSONPath](#jsonpath)
+- [Error handling](#error-handling)
+  * [Error handling examples without exceptions](#error-handling-examples-without-exceptions)
+  * [Disabling exceptions](#disabling-exceptions)
+  * [Exceptions](#exceptions)
+  * [Current location in document](#current-location-in-document)
+  * [Checking for trailing content](#checking-for-trailing-content)
+- [Rewinding](#rewinding)
+- [Newline-Delimited JSON (ndjson) and JSON lines](#newline-delimited-json-ndjson-and-json-lines)
+- [Parsing numbers inside strings](#parsing-numbers-inside-strings)
+- [Dynamic Number Types](#dynamic-number-types)
+- [Raw strings from keys](#raw-strings-from-keys)
+- [General direct access to the raw JSON string](#general-direct-access-to-the-raw-json-string)
+  * [Raw JSON string for objects and arrays](#raw-json-string-for-objects-and-arrays)
+- [Storing directly into an existing string instance](#storing-directly-into-an-existing-string-instance)
+- [Thread safety](#thread-safety)
+- [Standard compliance](#standard-compliance)
+- [Backwards compatibility](#backwards-compatibility)
+- [Examples](#examples)
+- [Performance tips](#performance-tips)
+- [Further reading](#further-reading)
 
 Requirements
 ------------------
 
-- A recent compiler (LLVM clang 6 or better, GNU GCC 7.4 or better, Xcode 11 or better) on a 64-bit (PPC, ARM or x64 Intel/AMD) POSIX systems such as macOS, freeBSD or Linux. We require that the compiler supports the C++11 standard or better.
-- Visual Studio 2017 or better under 64-bit Windows. Users should target a 64-bit build (x64 or ARM64) instead of a 32-bit build (x86). We support the LLVM clang compiler under Visual Studio (clang-cl) as well as as the regular Visual Studio compiler. For better release performance (both compile time and execution time), we recommend Visual Studio users adopt LLVM (clang-cl). We also support MinGW 64-bit under Windows.
+The simdjson library is widely deployed in popular systems such as the Node.js runtime
+environment.
 
+- A recent compiler (LLVM clang 6 or better, GNU GCC 7.4 or better, Xcode 11 or better) on POSIX systems such as macOS, FreeBSD or Linux. We require that the compiler supports the C++11 standard or better. We test the library on a big-endian system (IBM s390x with Linux).
+- Visual Studio 2017 or better. We support the LLVM clang compiler under Visual Studio (clang-cl) as well as the regular Visual Studio compiler. For better release performance (both compile time and execution time), we recommend Visual Studio users adopt LLVM (clang-cl). We discourage using GCC under Windows: there [is a long-running bug with GCC under Windows](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54412).
 
 Support for AVX-512 require a processor with AVX512-VBMI2 support (Ice Lake or better, AMD Zen 4 or better) under a 64-bit system and a recent compiler (LLVM clang 6 or better, GCC 8 or better, Visual Studio 2019 or better). You need a correspondingly recent assembler such as gas (2.30+) or nasm (2.14+): recent compilers usually come with recent assemblers. If you mix a recent compiler with an incompatible/old assembler (e.g., when using a recent compiler with an old Linux distribution), you may get errors at build time because the compiler produces instructions that the assembler does not recognize: you should update your assembler to match your compiler (e.g., upgrade binutils to version 2.30 or better under Linux) or use an older compiler matching the capabilities of your assembler.
 
-We test the library on a big-endian system (IBM s390x with Linux).
+
 
 Including simdjson
 ------------------
@@ -73,14 +78,14 @@ c++ myproject.cpp simdjson.cpp
 ```
 
 Note:
-- We recommend that you use simdjson by copying the single-header `simdjson.h` file along with the source file `simdjson.cpp` directly in your project, as they are part of [every release](https://github.com/simdjson/simdjson/releases) as assets. In this manner, you only have to compile `simdjson.cpp` as any other source file: it works well in every development environment. However, you may also use simdjson as a git submodule ([example](https://github.com/simdjson/cmakedemo)), using FetchContent ([example](https://github.com/simdjson/cmake_demo_single_file)), with ExternalProject_Add ([example](https://github.com/simdjson/cmakedemo_externalproject)) or with CPM ([example](https://github.com/cpm-cmake/CPM.cmake/tree/master/examples/simdjson)).
+- We recommend that you use simdjson by copying the single-header `simdjson.h` file along with the source file `simdjson.cpp` directly into your project, as they are part of [every release](https://github.com/simdjson/simdjson/releases) as assets. In this manner, you only have to compile `simdjson.cpp` as any other source file: it works well in every development environment. However, you may also use simdjson as a git submodule ([example](https://github.com/simdjson/cmakedemo)), using FetchContent ([example](https://github.com/simdjson/cmake_demo_single_file)), with ExternalProject_Add ([example](https://github.com/simdjson/cmakedemo_externalproject)) or with CPM ([example](https://github.com/cpm-cmake/CPM.cmake/tree/master/examples/simdjson)).
 - Users on macOS and other platforms where default compilers do not provide C++11 compliant by default should request it with the appropriate flag (e.g., `c++ -std=c++11 myproject.cpp simdjson.cpp`).
 - The library relies on [runtime CPU detection](implementation-selection.md): avoid specifying an architecture at compile time (e.g., `-march-native`) if you want your binaries to run everywhere.
 
 Using simdjson with package managers
 ------------------
 
-You can install the simdjson library on your system or in your project using multiple package managers such as MSYS2, the conan package manager, vcpkg, brew, the apt package manager (debian-based Linux systems), the FreeBSD package manager (FreeBSD), and so on. E.g., [we provide an complete example with vcpkg](https://github.com/simdjson/simdjson-vcpkg) that works under Windows. [Visit our wiki for more details](https://github.com/simdjson/simdjson/wiki/Installing-simdjson-with-a-package-manager).
+You can install the simdjson library on your system or in your project using multiple package managers such as MSYS2, the conan package manager, vcpkg, brew, the apt package manager (debian-based Linux systems), the FreeBSD package manager (FreeBSD), and so on. E.g., [we provide a complete example with vcpkg](https://github.com/simdjson/simdjson-vcpkg) that works under Windows. [Visit our wiki for more details](https://github.com/simdjson/simdjson/wiki/Installing-simdjson-with-a-package-manager).
 
 
 
@@ -175,6 +180,18 @@ auto json = padded_string::load("twitter.json"); // load JSON file 'twitter.json
 ondemand::document doc = parser.iterate(json); // position a pointer at the beginning of the JSON data
 ```
 
+If you prefer not to create your own `ondemand::parser` instance, you can access
+a thread-local version by calling `ondemand::parser.get_parser()`.
+
+
+```c++
+ondemand::document doc = ondemand::parser.get_parser().iterate(json);
+```
+
+However, you should be careful because a parser instance can only be used for one
+document at a time, thus it is only applicable when you are only parsing one
+document per thread at any one time.
+
 You can also create a padded string---and call `iterate()`:
 
 ```c++
@@ -234,7 +251,6 @@ Consider reusing the same buffers and limiting memory allocations.
 
 By default, the simdjson library throws exceptions (`simdjson_error`) on errors. We omit `try`-`catch` clauses from our illustrating examples: if you omit `try`-`catch` in your code, an uncaught exception will halt your program. It is also possible to use simdjson without generating exceptions, and you may even build the library without exception support at all. See [Error handling](#error-handling) for details.
 
-
 Some users may want to browse code along with the compiled assembly. You want to check out the following lists of examples:
 
 * [simdjson examples with errors handled through exceptions](https://godbolt.org/z/98Kx9Kqjn)
@@ -304,7 +320,7 @@ At the cost of some memory allocation, you may convert your `std::string_view` i
 For convenience, we also allow [storing an escaped string directly into an existing string instance](#storing-directly-into-an-existing-string-instance).
 
 The `std::string_view` class has become standard as part of C++17 but it is not always available
-on compilers which only supports C++11. When we detect that `string_view` is natively
+on compilers that only supports C++11. When we detect that `string_view` is natively
 available, we define the macro `SIMDJSON_HAS_STRING_VIEW`.
 
 When we detect that it is unavailable,
@@ -320,13 +336,15 @@ transcode the UTF-8 strings produced by the simdjson library to other formats. S
 Avoiding pitfalls: enable development checks
 --------------------
 
-We recommend that you first compile and run your code in Debug mode:
+We recommend that you first compile and run your code in debug mode:
 
 - under Visual Studio, it means having the `_DEBUG` macro defined,
--  for other compilers, it means leaving the `__OPTIMIZE__` macro undefined.
+- for many other compilers, it means leaving the `__OPTIMIZE__` macro undefined.
 
-The simdjson code will set `SIMDJSON_DEVELOPMENT_CHECKS=1` in debug mode.
-Alternatively, you can set the macro `SIMDJSON_DEVELOPMENT_CHECKS` to 1 prior to including
+The simdjson code will set `SIMDJSON_DEVELOPMENT_CHECKS=1` in debug mode. Because
+the C++ standard does not provide a direct way of checking for a debug build, and
+because you may want the checks while building with optimizations, you can set
+the  macro `SIMDJSON_DEVELOPMENT_CHECKS` to 1 prior to including
 the `simdjson.h` header to enable these additional checks: just make sure you remove the
 definition once your code has been tested. When `SIMDJSON_DEVELOPMENT_CHECKS` is set to 1, the
 simdjson library runs additional (expensive) tests on your code to help ensure that you are
@@ -335,9 +353,12 @@ using the library in a safe manner.
 Once your code has been tested, you can then run it in
 Release mode: under Visual Studio, it means having the `_DEBUG` macro undefined, and, for other
 compilers, it means setting `__OPTIMIZE__` to a positive integer. You can also forcefully
-disable these checks by setting `SIMDJSON_DEVELOPMENT_CHECKS` to 0. Once your code is tested, we
-further encourage you to define `NDEBUG` in your Release builds to disable additional runtime
-testing and get the best performance.
+disable these checks by setting `SIMDJSON_DEVELOPMENT_CHECKS` to 0.
+
+Once your code is tested, we further encourage you to define `NDEBUG` in your release
+builds to disable additional runtime testing and get the best performance. We
+disable these checks on a best-effort basis but the C++ standard does not provide
+a direct way to check for a release build.
 
 Using the parsed JSON
 ---------------------
@@ -350,9 +371,8 @@ and arrays (`simdjson::ondemand::array`).
 We also have a generic ephemeral type (`simdjson::ondemand::value`) which represents a potential
 array or object, or scalar type (`double`, `uint64_t`, `int64_t`, `bool`, `null`, string) inside
 an array or an object. Both generic types (`simdjson::ondemand::document` and
-`simdjson::ondemand::value`) have a `type()` method returning a `json_type` value describing the
-value (`json_type::array`, `json_type::object`, `json_type::number`, `json_type::string`,
-`json_type::boolean`, `json_type::null`). A generic value (`simdjson::ondemand::value`)
+`simdjson::ondemand::value`) have a `type()` method returning a `json_type` value describing indicating the type (`json_type::array`, `json_type::object`, `json_type::number`, `json_type::string`,
+`json_type::boolean`, `json_type::null`, and `json_type::unknown` for unrecognized types). The `type()` method does not consume nor validate the value: e.g., you must still call `is_null()` to check that the value is a `null` even if `json_type::null` is returned. Starting with simdjson 4.0, we return `json_type::unknown` for bad tokens such as the `NaN` token in `{"key":NaN}`. A `json_type::unknown` type value indicates an error in the JSON document but you might still be able to proceed, see [General direct access to the raw JSON string](#general-direct-access-to-the-raw-json-string). A generic value (`simdjson::ondemand::value`)
 is only valid temporarily, as soon as you access other values, other keys in objects, etc.
 it becomes invalid: you should therefore consume the value immediately by converting it to a
 scalar type, an array or an object.
@@ -385,7 +405,7 @@ support for users who avoid exceptions. See [the simdjson error handling documen
   ondemand::object and ondemand::array. We also have explicit methods such as `get_string()`, `get_double()`,
   `get_uint64()`, `get_int64()`, `get_bool()`, `get_object()` and `get_array()`. After a cast or an explicit method,
   the number, string or boolean will be parsed, or the initial `{` or `[` will be verified for `ondemand::object` and `ondemand::array`. An exception may be thrown if
-  the cast is not possible: there error code is `simdjson::INCORRECT_TYPE` (see [Error handling](#error-handling)). Importantly, when getting an ondemand::object or ondemand::array instance, its content is
+  the cast is not possible: the error code is `simdjson::INCORRECT_TYPE` (see [Error handling](#error-handling)). Importantly, when getting an ondemand::object or ondemand::array instance, its content is
   not validated: you are only guaranteed that the corresponding initial character (`{` or `[`) is present. Thus,
   for example, you could have an ondemand::object instance pointing at the invalid JSON `{ "this is not a valid object" }`: the validation occurs as you access the content.
   The `get_string()` returns a valid UTF-8 string, after
@@ -432,7 +452,7 @@ support for users who avoid exceptions. See [the simdjson error handling documen
 * **Field Access:** To get the value of the "foo" field in an object, use `object["foo"]`. This will
   scan through the object looking for the field with the matching string, doing a character-by-character
   comparison. It may generate the error `simdjson::NO_SUCH_FIELD` if there is no such key in the object, it may throw an exception (see [Error handling](#error-handling)). For efficiency reason, you should avoid looking up the same field repeatedly: e.g., do
-  not do `object["foo"]` followed by `object["foo"]` with the same `object` instance. For best performance, you should try to query the keys in the same order they appear in the document. If you need several keys and you cannot predict the order they will appear in, it is recommended to iterate through all keys `for(auto field : object) {...}`. Generally, you should not mix and match iterating through an object (`for(auto field : object) {...}`) and key accesses (`object["foo"]`): if you need to iterate through an object after a key access, you need to call `reset()` on the object. Whenever you call `reset()`, you need to keep in mind that though you can iterate over the array repeatedly, values should be consumedonly once (e.g., repeatedly calling `unescaped_key()` on the same  key is forbidden). Keep in mind that On-Demand does not buffer or save the result of the parsing: if you repeatedly access `object["foo"]`, then it must repeatedly seek the key and parse the content. The library does not provide a distinct function to check if a key is present, instead we recommend you attempt to access the key: e.g., by doing `ondemand::value val{}; if (!object["foo"].get(val)) {...}`, you have that `val` contains the requested value inside the if clause.  It is your responsibility as a user to temporarily keep a reference to the value (`auto v = object["foo"]`), or to consume the content and store it in your own data structures. If you consume an
+  not do `object["foo"]` followed by `object["foo"]` with the same `object` instance. Generally, you should not mix and match iterating through an object (`for(auto field : object) {...}`) and key accesses (`object["foo"]`): if you need to iterate through an object after a key access, you need to call `reset()` on the object. Whenever you call `reset()`, you need to keep in mind that though you can iterate over the array repeatedly, values should be consumedonly once (e.g., repeatedly calling `unescaped_key()` on the same  key is forbidden). Keep in mind that On-Demand does not buffer or save the result of the parsing: if you repeatedly access `object["foo"]`, then it must repeatedly seek the key and parse the content. The library does not provide a distinct function to check if a key is present, instead we recommend you attempt to access the key: e.g., by doing `ondemand::value val{}; if (!object["foo"].get(val)) {...}`, you have that `val` contains the requested value inside the if clause.  It is your responsibility as a user to temporarily keep a reference to the value (`auto v = object["foo"]`), or to consume the content and store it in your own data structures. If you consume an
   object twice: `std::string_view(object["foo"]` followed by `std::string_view(object["foo"]` then your code
   is in error. Furthermore, you can only consume one field at a time, on the same object. The
   value instance you get from  `content["bids"]` becomes invalid when you call `content["asks"]`.
@@ -495,7 +515,7 @@ support for users who avoid exceptions. See [the simdjson error handling documen
   > double y = doc["y"]; // The cursor is now after the 2 (at })
   > double x = doc["x"]; // Success: [] loops back around to find "x"
   > ```
-* **Output to strings:** Given a document, a value, an array or an object in a JSON document, you can output a JSON string version suitable to be parsed again as JSON content: `simdjson::to_json_string(element)`. A call to `to_json_string` consumes fully the element: if you apply it on a document, the JSON pointer is advanced to the end of the document. The `simdjson::to_json_string` does not allocate memory. The `to_json_string` function should not be confused with retrieving the value of a string instance which are escaped and represented using a lightweight `std::string_view` instance pointing at an internal string buffer inside the parser instance. To illustrate, the first of the following two code segments will print the unescaped string `"test"` complete with the quote whereas the second one will print the escaped content of the string (without the quotes).
+* **Output to strings:** Given a document, a value, an array or an object in a JSON document, you can output a JSON string version suitable to be parsed again as JSON content: `simdjson::to_json_string(element)`. A call to `to_json_string` consumes fully the element: if you apply it on a document, the internal pointer is advanced to the end of the document. The `simdjson::to_json_string` does not allocate memory. The `to_json_string` function should not be confused with retrieving the value of a string instance which are escaped and represented using a lightweight `std::string_view` instance pointing at an internal string buffer inside the parser instance. To illustrate, the first of the following two code segments will print the unescaped string `"test"` complete with the quote whereas the second one will print the escaped content of the string (without the quotes).
   > ```C++
   > // serialize a JSON to an escaped std::string instance so that it can be parsed again as JSON
   > auto silly_json = R"( { "test": "result"  }  )"_padded;
@@ -678,6 +698,9 @@ support for users who avoid exceptions. See [the simdjson error handling documen
         cout << "null";
       }
       break;
+    case ondemand::json_type::unknown:
+      cout << "unknown"; // indicates an error
+      break;
     }
   }
   void basics_treewalk() {
@@ -813,15 +836,17 @@ for (ondemand::object points : parser.iterate(points_json)) {
 Adding support for custom types
 ----------------------
 
-There are 2 main ways provided by simdjson to deserialize a value into a custom type:
+There are 3 main ways provided by simdjson to deserialize a value into a custom type:
 
 1. Provide a [**template specialization** for member functions](https://en.cppreference.com/w/cpp/language/template_specialization#Members_of_specializations)
    1. Specialize `simdjson::ondemand::document::get` for the whole document
    2. Specialize `simdjson::ondemand::value::get` for each value
 2. Using `tag_invoke` *(the recommended way if your system supports C++20 or better)*
+3. Using static reflection (requires C++26 or better)
 
-We describe both of them in the following sections. Most users who have systems compatible with
+We describe all of them in the following sections. Most users who have systems compatible with
 C++20 or better should skip ahead to [using `tag_invoke` for custom types (C++20)](#2-use-tag_invoke-for-custom-types-c20) as it is more powerful and simpler.
+The C++26 approach is even simpler.
 
 ### 1. Specialize `simdjson::ondemand::value::get` to get custom types (pre-C++20)
 
@@ -859,13 +884,13 @@ type:
 
 We may do so by providing additional template definitions to the `ondemand::value` type.
 We may start by providing a definition for `std::vector<double>` as follows. Observe
-how we guard the code with `#if !SIMDJSON_SUPPORTS_DESERIALIZATION`: that is because the necessary code
+how we guard the code with `#if !SIMDJSON_SUPPORTS_CONCEPTS`: that is because the necessary code
 is automatically provided by simdjson if C++20 (and concepts) are available.
 See [Use `tag_invoke` for custom types](#2-use-tag_invoke-for-custom-types-c20) if you have
 C++20 support.
 
 ```c++
-#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+#if !SIMDJSON_SUPPORTS_CONCEPTS
 // The code is unnecessary with C++20:
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
@@ -921,7 +946,7 @@ struct Car {
   std::vector<double> tire_pressure;
 };
 
-#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+#if !SIMDJSON_SUPPORTS_CONCEPTS
 // This code is not necessary if you have a C++20 compliant system:
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
@@ -1022,7 +1047,7 @@ struct Car {
   std::vector<double> tire_pressure;
 };
 
-#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+#if !SIMDJSON_SUPPORTS_CONCEPTS
 // This code is not necessary if you have a C++20 compliant system:
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
@@ -1081,6 +1106,32 @@ int main(void) {
 
 ### 2. Use `tag_invoke` for custom types (C++20)
 
+The simdjson library takes advantage of C++20. An immediate benefit
+is that you can deserialize JSON data directly in standard containers
+and other standard value types:
+
+```C++
+simdjson::padded_string json = R"({"data" : [1,2,3,4]})"_padded;
+
+simdjson::ondemand::parser parser;
+simdjson::ondemand::document d = parser.iterate(json);
+std::vector<uint8_t> array = d["data"].get<std::vector<uint8_t>>();
+```
+
+Appending to an existing container is just as easy:
+
+```C++
+std::vector<uint32_t> array = {0, 0};
+
+simdjson::padded_string json = R"({"data" : [1,2,3,4]})"_padded;
+
+simdjson::ondemand::parser parser;
+simdjson::ondemand::document d = parser.iterate(json);
+
+d["data"].get<std::vector<uint32_t>>(array);
+// array is now {0,0,1,2,3,4}
+```
+
 In C++20, the standard introduced the notion of *customization point*.
 A customization point is a function or function object that can be customized for different types. It allows library authors to provide default behavior while giving users the ability to override this behavior for specific types.
 
@@ -1091,7 +1142,7 @@ The first argument is usually a tag type (often an empty struct) that uniquely i
 
 If your system supports C++20, we recommend that you adopt the `tag_invoke` approach
 instead to deserialize custom types. It may prove to be considerably simpler. When
-simdjson detects the necessary support, it sets the `SIMDJSON_SUPPORTS_DESERIALIZATION` macro
+simdjson detects the necessary support, it sets the `SIMDJSON_SUPPORTS_CONCEPTS` macro
 to 1, otherwise it is set to 0.
 
 Consider a custom class `Car`:
@@ -1105,7 +1156,7 @@ struct Car {
 };
 ```
 
-Observe how we defined the class to use types that simdjson does not directly support (`float`, `int`).
+Observe how we define the class to use types that simdjson does not directly support (`float`, `int`).
 With C++20 support, the library grabs from the JSON the generic type (`double`, `int`) and then it
 casts it automatically.
 
@@ -1257,7 +1308,7 @@ You may also conditionally fill in `std::optional` values.
   // error is simdjson::SUCCESS
 ```
 
-You can also deserialized to map-like types with keys that can be constructed
+You can also deserialize to map-like types with keys that can be constructed
 from `std::string_view` instances:
 
 
@@ -1268,8 +1319,8 @@ from `std::string_view` instances:
 })"_padded;
   ondemand::parser parser;
   ondemand::document doc = parser.iterate(json);
-  std:map<std::string,Car> cars;
-  error = doc.get<std:map<std::string,Car>>().get(cars);
+  std::map<std::string,Car> cars;
+  error = doc.get<std::map<std::string,Car>>().get(cars);
   // car has value car1->Car{"Toyota", "Camry", 2018, {40.1f, 39.9f}}
   // error is simdjson::SUCCESS
 ```
@@ -1309,6 +1360,184 @@ With this code, deserializing an `std::list<Car>` instance would capture only th
 that are not made by Toyota.
 
 
+
+
+### 3. Using static reflection (C++26)
+
+If you have a C++26 compatible compiler, you can compile
+your code with the `SIMDJSON_STATIC_REFLECTION` macro set:
+
+```cpp
+#define SIMDJSON_STATIC_REFLECTION 1
+//...
+#include "simdjson.h"
+```
+
+Then you can deserialize a type such as `Car` automatically:
+
+
+
+```C++
+struct Car {
+  std::string make;
+  std::string model;
+  int year;
+  std::vector<float> tire_pressure;
+};
+
+std::string json =  R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] } )";
+simdjson::ondemand::parser parser;
+simdjson::ondemand::document doc = parser.iterate(simdjson::pad(json));
+Car c = doc.get<Car>();
+```
+
+
+We try to automate the parsing of any given structure or class
+by looking at its non-static public members. At compile-time,
+the library looks at a simple structure like `Car` and
+maps it to parsing code. We call the default constructor,
+and then assign values to the public members.
+
+
+If a key is missing in the JSON document, an error is generated (`NO_SUCH_FIELD`),
+except if the attribute is of a type like `std::optional` (`simdjson::concepts::optional_type`).
+
+
+Sometimes you might want to only extract some attributes from the JSON. You can
+achieve this result with the `extract_into` method supported by both `object` and
+`document` instances. It returns an error code that evaluates to false when there
+is no error.
+
+Consider the following example where you only want to parse the make and the model
+from the JSON:
+
+```cpp
+struct car_type {
+    std::string make;
+    std::string model;
+    uint64_t year;
+    std::vector<double> tire_pressure;
+};
+
+void f() {
+  auto json = R"( {
+         "make": "Toyota",
+         "model": "Camry",
+         "year": 2024,
+         "tire_pressure": [ 40.1, 39.9 ]
+       } )"_padded;
+  ondemand::parser parser;
+  ondemand::document doc = parser.iterate(json);
+  Car car{};
+  auto error = doc.extract_into<"make","model">(car);
+  if(error) { /** error handling */ }
+  // only car.make and car.
+}
+```
+
+#### Special cases
+
+However, there are instances where the construction cannot
+be easily automated. Let us consider a class without any
+public member.
+
+```cpp
+
+class MyDate {
+public:
+    void assign(std::string_view str) {
+        date_str = str;
+    }
+    const std::string& to_string() const {
+        return date_str;
+    }
+private:
+    std::string date_str;
+};
+```
+
+This class has a default constructor, but it must be initialized
+with the `assign` method. We need to help the library with
+a `tag_invoke` function (just as in the C++20 case).
+
+
+```cpp
+namespace simdjson {
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, MyDate& date) {
+    std::string_view str;
+    auto error = val.get_string().get(str);
+    if(error) { return error; }
+    date.assign(str);
+  return simdjson::SUCCESS;
+}
+} // namespace simdjson
+```
+
+Once this is done, we can now automatically parse a custom type
+like `complicated_weather_data` containing `MyDate` values.
+
+
+```cpp
+struct complicated_weather_data {
+    std::vector<MyDate> time;
+    std::vector<float> temperature;
+};
+```
+
+The code might be as simple as the following.
+
+```cpp
+auto padded = R"({"time":["2023-03-15T12:00:00Z"],"temperature":[42]})"_padded;
+simdjson::ondemand::parser parser;
+simdjson::ondemand::document doc = parser.iterate(padded);
+complicated_weather_data p = doc.get<complicated_weather_data>();
+```
+
+Thus you can combine C++26 static reflection with custom deserialization
+functions.
+
+You can also automatically serialize the `Car` instance to a JSON string, see
+our [Builder documentation](builder.md).
+
+
+
+### The simdjson::from shortcut (experimental, C++20)
+
+
+For even more convenience, you can parse a JSON document directly to a supported
+type without a document instance like so:
+
+```cpp
+Car car = simdjson::from(json);
+```
+
+You can also use the `simdjson::from` syntax without exceptions, like so:
+```cpp
+Car car;
+simdjson::error_code err = simdjson::from(json_car).get(car);
+```
+
+You can also use the `simdjson::from` syntax to iterate over an array.
+
+```cpp
+for(auto val : simdjson::from(json).array()) {
+  Car c = val.get<Car>(); // ...
+}
+```
+
+Standard STL types are supported:
+
+
+```cpp
+std::map<std::string, std::string> obj =
+       simdjson::from(R"({"key": "value"})"_padded);
+```
+
+
+The `simdjson::from` construction is EXPERIMENTAL and subject to changes.
+
 Minifying JSON strings without parsing
 ----------------------
 
@@ -1350,9 +1579,9 @@ If you find yourself needing only fast Unicode functions, consider using the sim
 JSON Pointer
 ------------
 
-The simdjson library also supports [JSON pointer](https://tools.ietf.org/html/rfc6901) through the `at_pointer()` method, letting you reach further down into the document in a single call. JSON pointer is supported by both the [DOM approach](https://github.com/simdjson/simdjson/blob/master/doc/dom.md#json-pointer) as well as the On-Demand approach.
+The simdjson library also supports [JSON pointer](https://tools.ietf.org/html/rfc6901) through the `at_pointer()` method, letting you reach further down into the document in a single call. JSON Pointer is supported by both the [DOM approach](https://github.com/simdjson/simdjson/blob/master/doc/dom.md#json-pointer) as well as the On-Demand approach.
 
-**Note:** The On-Demand implementation of JSON pointer relies on `find_field` which implies that it does not unescape keys when matching.
+**Note:** The On-Demand implementation of JSON Pointer relies on `find_field` which implies that it does not unescape keys when matching.
 
 Consider the following example:
 
@@ -1372,7 +1601,7 @@ index allows you to select the indexed node. Within objects, the string value of
 select the value. If your keys contain the characters '/' or '~', they must be escaped as '~1' and
 '~0' respectively. An empty JSON Pointer Path refers to the whole document.
 
-For multiple JSON pointer queries on a document, one can call `at_pointer` multiple times.
+For multiple JSON Pointer queries on a document, one can call `at_pointer` multiple times.
 
 ```c++
 auto cars_json = R"( [
@@ -1527,7 +1756,7 @@ x = obj.at_path("$.d.foo2.a.2"); // 30
 Error handling
 --------------
 
-Error handing with exception and a single try/catch clause makes the code simple, but it gives you little control over errors. For easier debugging or more robust error handling, you may want to consider our exception-free approach.
+Error handling with exception and a single try/catch clause makes the code simple, but it gives you little control over errors. For easier debugging or more robust error handling, you may want to consider our exception-free approach.
 
 The entire simdjson API is usable with and without exceptions. All simdjson APIs that can fail return `simdjson_result<T>`, which is a &lt;value, error_code&gt;
 pair. You can retrieve the value with .get() without generating an exception, like so:
@@ -2121,7 +2350,8 @@ The simdjson library supports parsing valid numbers inside strings which makes i
 three methods: `get_double_in_string`, `get_int64_in_string` and  `get_uint64_in_string`. However, it is important to note that these methods are not substitute to the regular
 `get_double`, `get_int64` and `get_uint64`. The usage of the `get_*_in_string` methods is solely to parse valid JSON numbers inside strings, and so we expect users to call these
 methods appropriately. In particular, a valid JSON number has no leading and no trailing whitespaces, and the strings `"nan"`, `"1e"` and `"infinity"` will not be accepted as valid
-numbers. As an example, suppose we have the following JSON text:
+numbers (although you have access to the raw string with the `raw_json_token()` method,  see [General direct access to the raw JSON string](#general-direct-access-to-the-raw-json-string)
+). As an example, suppose we have the following JSON text:
 
 ```c++
 auto json =
@@ -2246,6 +2476,11 @@ Thus it is a dynamically typed number. Before accessing the value, you must dete
 such a number of `get_number()`, you get the error `BIGINT_ERROR`. You can access the underlying string of digits with the function `raw_json_token()` which returns a `std::string_view` instance starting at the beginning of the digit. You can also call `get_double()` to get a floating-point approximation.
 
 
+  By default, the string `-0` is parsed as the integer 0 as in Python or C++. If you set the macro
+  `SIMDJSON_MINUS_ZERO_AS_FLOAT` to `1` when building simdjson, you can get that `-0` is mapped to `-0.0`
+  as in JavaScript. You can get the desired effect by building simdjson with cmake setting the
+  `SIMDJSON_MINUS_ZERO_AS_FLOAT` to on: `cmake -B build -D SIMDJSON_MINUS_ZERO_AS_FLOAT=ON`.
+
 You must check the type before accessing the value: it is an error to call `get_int64()` when `number.get_number_type()` is not `number_type::signed_integer` and when `number.is_int64()` is false. You are responsible for this check as the user of the library.
 
 The `get_number()` function is designed with performance in mind. When calling `get_number()`, you scan the number string only once, determining efficiently the type and storing it in an efficient manner.
@@ -2435,10 +2670,36 @@ The `raw_json_token()` should be fast and free of allocation.
 Given a quote-deliminated string, you find the string sequence inside the quote with a
 single line of code:
 
-```C++
+```cpp
 std::string_view noquote(std::string_view v) { return {v.data()+1, v.find_last_of('"')-1}; }
 ```
 
+
+The `raw_json_token()` method can enable you to provide fallbacks when parsing fails.
+Consider the following example.
+
+```cpp
+    padded_string json = "{\"key\": NaN}"_padded;
+    simdjson::ondemand::parser parser;
+    simdjson::ondemand::document doc = parser.iterate(json);
+    simdjson::ondemand::object object = doc.get_object();
+    simdjson::ondemand::value val = object["key"];
+    simdjson::ondemand::json_type type = val.type();
+    // type == simdjson::ondemand::json_type::unknown
+    try {
+      double num = val.get_double();
+    } catch (const simdjson::simdjson_error& e) {
+      // e == simdjson::error_code::INCORRECT_TYPE
+      std::string_view str = val.raw_json_token();
+      // str == "NaN"
+    }
+```
+
+The NaN is not supported in JSON. However, in the On-Demand API, you can check
+the string corresponding to the JSON token and determine how to handle it.
+
+### Raw JSON string for objects and arrays
+
 If your value is an array or an object, `raw_json_token()` returns effectively a single
 character (`[`) or (`}`) which is not very useful. For arrays and objects, we have another
 method called `raw_json()` which consumes (traverses) the array or the object.
@@ -2546,15 +2807,16 @@ a parameter a reference to a `std::string`.
   ondemand::parser parser;
   ondemand::document doc = parser.iterate(json);
   std::string name;
-  doc["name"].get_string(name);
+  auto error = doc["name"].get_string(name);
+  if(error) { /* handle error */ }
 ```
 
 The same routine can be written without exceptions handling:
 
 ```C++
   std::string name;
-  auto err = doc["name"].get_string(name);
-  if (err) { /* handle error */ }
+  auto error = doc["name"].get_string(name);
+  if (error) { /* handle error */ }
 ```
 
 The `std::string` instance, once created, is independent. Unlike our `std::string_view` instances,
@@ -2573,6 +2835,20 @@ can use it with features such as `std::optional`:
   // value was populated with "3.1416"
 ```
 
+You can generally convert any answer that would return an `std::string_view`.
+
+```cpp
+  auto json = R"({"\u0062\u0065\u0062\u0065": 2} })"_padded;
+  ondemand::parser parser;
+  ondemand::document doc = parser.iterate(json);
+  ondemand::object object = doc.get_object();
+  for (auto field : object) {
+    std::string key;
+    error = field.unescaped_key().get(key);
+    if(error) { /* */ }
+  }
+```
+
 You should be mindful of the trade-off: allocating multiple
 `std::string` instances can become expensive.
 
@@ -2943,10 +3219,45 @@ Performance tips
 - The On-Demand front-end works best when doing a single pass over the input: avoid calling `count_elements`, `rewind`, `reset` and similar methods.
 - If you are familiar with assembly language, you may use the online tool godbolt to explore the compiled code. The following example may work: [https://godbolt.org/z/xE4GWs573](https://godbolt.org/z/xE4GWs573).
 - Given a field `field` in an object, calling `field.key()` is often faster than `field.unescaped_key()` so if you do not need an unescaped `std::string_view` instance, prefer `field.key()`. Similarly, we expect `field.escaped_key()` to be faster than `field.unescaped_key()` even though both return a `std::string_view` instance.
-- For release builds, we recommend setting `NDEBUG` pre-processor directive when compiling the `simdjson` library. Importantly, using the optimization flags `-O2` or `-O3` under GCC and LLVM clang does not set the `NDEBUG` directive, you must set it manually (e.g., `-DNDEBUG`).
+- For release builds, we recommend setting the `NDEBUG` pre-processor directive when compiling the `simdjson` library. Importantly, using the optimization flags `-O2` or `-O3` under GCC and LLVM clang does not set the `NDEBUG` directive, you must set it manually (e.g., `-DNDEBUG`).
 - For long streams of JSON documents, consider [`iterate_many`](iterate_many.md) and [`parse_many`](parse_many.md) for better performance.
 - Never seek to access a field twice (e.g., o["data"] and later again o["data"]). Instead capture once an ondemand::value and reuse it.
-- If you must access several different keys in an object, it might be preferable to iterate through all the fields in the object instead, and branch on the field keys.
+- If you must access several different keys in an object, it might be preferable to iterate through all the fields in the object instead, and branch on the field keys. Consider this example.
+  ```cpp
+
+    auto json = R"({"price": 123.456789, "volume": 9999,
+                    "timestamp": "2025-09-04T09:45:00Z",
+                    "symbol": "XYZ", "currency": "USD", "change": 1.23,
+                    "isActive": true})"_padded;
+
+    simdjson::ondemand::parser parser;
+    simdjson::ondemand::document doc = parser.iterate(json);
+
+    for(auto keyvalue : doc.get_object()) {
+        simdjson::ondemand::raw_json_string key = keyvalue.key();
+        switch(key[0]) {
+            case 'p': // price
+                if (key == "price") {
+                    std::string_view price_str = keyvalue.value().raw_json();
+                    std::cout << "Price: " << price_str << std::endl;
+                }
+                break;
+            case 'v': // volume
+                if (key == "volume") {
+                    std::string_view volume_str = keyvalue.value().raw_json();
+                    std::cout << "Volume: " << volume_str << std::endl;
+                }
+                break;
+            case 't': // timestamp
+                if (key == "timestamp") {
+                    std::string_view timestamp = keyvalue.value();
+                    std::cout << "Timestamp: " << timestamp << std::endl;
+                }
+                break;
+            default: break;
+        }
+    }
+  ```
 - If possible, refer to each object and array in your code once. For example, the following code repeatedly refers to the `"data"` key to create an object...
 	```C++
 	std::string_view make = o["data"]["make"];

doc/builder.md

@@ -0,0 +1,366 @@
+Builder
+==========
+
+Sometimes you want to generate JSON string outputs efficiently.
+The simdjson library provides high-performance low-level facilities.
+When using these low-level functionalities, you are responsible to
+define the structure of your JSON document. Our more advanced interface
+automates the process using C++26 static reflection: you get both high
+speed and high convenience.
+
+- [Builder](#builder)
+  * [Overview: string_builder](#overview--string-builder)
+  * [Example: string_builder](#example--string-builder)
+  * [C++26 static reflection](#c--26-static-reflection)
+    + [Without `string_buffer` instance](#without--string-buffer--instance)
+    + [Without `string_buffer` instance but with explicit error handling](#without--string-buffer--instance-but-with-explicit-error-handling)
+
+Overview: string_builder
+---------------------------
+
+The string_builder class is a low-level utility for constructing JSON strings representing documents. It is optimized for performance, potentially leveraging kernel-specific features like SIMD instructions for tasks such as string escaping. This class supports atomic types (e.g., booleans, numbers, strings) but does not handle composed types directly (like arrays or objects).
+Note that JSON strings are always encoded as UTF-8.
+
+An `string_builder` is created with an initial buffer capacity (e.g., 1kB). The memory
+is reallocated when needed.
+The efficiency of `string_builder` stems from its internal use of a resizable array or buffer. When you append data, it adds the characters to this buffer, resizing it only when necessary, typically in a way that minimizes reallocations. This approach contrasts with regular string concatenation, where each operation creates a new string, copying all previous content, leading to quadratic time complexity for repeated concatenations.
+
+
+It has the following methods to add content to the string:
+
+
+- `append(number_type v)`: Appends a number (including booleans) to the JSON buffer. Booleans are converted to the strings "false" or "true". Numbers are formatted according to the JSON standard, with floating-point numbers using the shortest representation that accurately reflects the value.
+- `append(char c)`: Appends a single character to the JSON buffer.
+- `append_null()`: Appends the string "null" to the JSON buffer.
+- `clear()`: Clears the contents of the JSON buffer, resetting the position to 0 while retaining the allocated capacity.
+- `escape_and_append(std::string_view input)`: Appends a string view to the JSON buffer after escaping special characters (e.g., quotes, backslashes) as required by JSON.
+- `escape_and_append_with_quotes(std::string_view input)` Appends a string view surrounded by double quotes (e.g., "input") to the JSON buffer after escaping special characters. For constant strings, you may also do `escape_and_append_with_quotes<"mystring">()`.
+- `escape_and_append_with_quotes(char input)`: Appends a single character surrounded by double quotes (e.g., "c") to the JSON buffer after escaping it if necessary.
+- `append_raw(const char *c)`: Appends a null-terminated C string directly to the JSON buffer without escaping.
+- `append_raw(std::string_view input)`: Appends a string view directly to the JSON buffer without escaping.
+- `append_raw(const char *str, size_t len)`: Appends a specified number of characters from a C string directly to the JSON
+- `append_key_value(key,value)`: Appends a key and a value (`"json":somevalue`)
+- `append_key_value<"mykey">(value)`: Appends a key and a value (`"json":somevalue`), useful when the key is a compile-time constant (C++20).
+
+After writing the content, if you have reasons to believe that the content might violate UTF-8 conventions, you can check it as follows:
+
+- `validate_unicode()`: Checks if the content in the JSON buffer is valid UTF-8. Returns: true if the content is valid UTF-8, false otherwise.
+
+You might need to do unicode validation if you have strings in your data structures containing
+malformed UTF-8. Note that we do not automatically call `validate_unicode()`.
+
+Once you are satisfied, you can recover the string as follows:
+
+- `operator std::string()`: Converts the JSON buffer to an std::string. (Might throw if an error occurred.)
+- `operator std::string_view()`: Converts the JSON buffer to an std::string_view.  (Might throw if an error occurred.)
+- `view()`: Returns a view of the written JSON buffer as a `simdjson_result<std::string_view>` (C++20).
+
+The later method (`view()`) is recommended.  For performance reasons, we expect you to explicitly call `validate_unicode()` as needed (e.g., prior to calling `view()`).
+
+Example: string_builder
+---------------------------
+
+```C++
+struct Car {
+    std::string make;
+    std::string model;
+    int64_t year;
+    std::vector<double> tire_pressure;
+};
+
+void serialize_car(const Car& car, simdjson::builder::string_builder& builder) {
+    // start of JSON
+    builder.start_object();
+
+    // "make"
+    builder.append_key_value("make", car.make);
+    builder.append_comma();
+
+    // "model"
+    builder.append_key_value("model", car.model);
+    builder.append_comma();
+
+    // "year"
+    builder.append_key_value("year", car.year);
+    builder.append_comma();
+
+    // "tire_pressure"
+    builder.escape_and_append_with_quotes("tire_pressure");
+    builder.append_colon();
+    builder.start_array();
+    // vector tire_pressure
+    for (size_t i = 0; i < car.tire_pressure.size(); ++i) {
+        builder.append(car.tire_pressure[i]);
+        if (i < car.tire_pressure.size() - 1) {
+            builder.append_comma();
+        }
+    }
+    builder.end_array();
+    builder.end_object();
+}
+
+bool car_test() {
+    simdjson::builder::string_builder sb;
+    Car c = {"Toyota", "Corolla", 2017, {30.0,30.2,30.513,30.79}};
+    serialize_car(c, sb);
+    std::string_view p{sb};
+    // p holds the JSON:
+    // "{\"make\":\"Toyota\",\"model\":\"Corolla\",\"year\":2017,\"tire_pressure\":[30.0,30.2,30.513,30.79]}"
+    return true;
+}
+```
+
+
+
+
+The `string_builder` constructor takes an optional parameter which specifies the initial
+memory allocation in byte. If you know approximately the size of your JSON output, you can
+pass this value as a parameter (e.g., `simdjson::builder::string_builder sb{1233213}`).
+
+The `string_builder` might throw an exception in case of error when you cast it result to `std::string_view`. If you wish to avoid exceptions, you can use the following programming pattern:
+
+```cpp
+    std::string_view p;
+    if(sb.view().get(p)) {
+        return false; // there was an error
+    }
+```
+
+In all cases, the `std::string_view` instance depends the corresponding `string_builder` instance.
+
+### C++20
+
+
+
+If you have C++20, you can simplify the code, as the `std::vector<double>` is automatically supported. Further, we can pass the keys (which are compile-time
+constant) as template parameter (for improved performance).
+
+```cpp
+    Car c = {"Toyota", "Corolla", 2017, {30.0,30.2,30.513,30.79}};
+    simdjson::builder::string_builder sb;
+    sb.start_object();
+    sb.append_key_value<"make">(c.make);
+    sb.append_comma();
+    sb.append_key_value<"model">(c.model);
+    sb.append_comma();
+    sb.append_key_value<"year">(c.year);
+    sb.append_comma();
+    sb.append_key_value<"tire_pressure">(c.tire_pressure);
+    sb.end_object();
+    std::string_view p = sb.view();
+```
+
+With C++20, you can similarly handle standard containers transparently.
+For example, you can serialize `std::map<std::string,T>` types.
+
+```cpp
+    std::map<std::string,double> c = {{"key1", 1}, {"key2", 1}};
+    simdjson::builder::string_builder sb;
+    sb.append(c);
+    std::string_view p = sb.view();
+```
+
+You can also serialize `std::vector<T>` types.
+
+```cpp
+    std::vector<std::vector<double>> c = {{1.0, 2.0}, {3.0, 4.0}};
+    simdjson::builder::string_builder sb;
+    sb.append(c);
+    std::string_view p = sb.view();
+```
+
+You can also skip the creation for the `string_builder` instance in such simple cases.
+
+```cpp
+std::vector<std::vector<double>> c = {{1.0, 2.0}, {3.0, 4.0}};
+std::string json = simdjson::to_json(c);
+```
+
+We also have an overload for when you want to reuse the same `std::string` instance:
+
+
+```cpp
+std::vector<std::vector<double>> c = {{1.0, 2.0}, {3.0, 4.0}};
+std::string json;
+auto error = simdjson::to_json(c, json);
+if(error) { /* there was an error */ }
+```
+
+
+We do recommend that you create and reuse the `string_builder` instance for performance
+reasons.
+
+You can also add custom serialization functions using a `tag_invoke` function.
+For example, the following
+function will allow you to serialize instances of the type `Car`.
+
+```cpp
+#include <simdjson>
+
+struct Car {
+  std::string make;
+  std::string model;
+  int64_t year;
+  std::vector<float> tire_pressure;
+};
+
+namespace simdjson {
+
+template <typename builder_type>
+void tag_invoke(serialize_tag, builder_type &builder, const Car& car) {
+  builder.start_object();
+  builder.append_key_value("make", car.make);
+  builder.append_comma();
+  builder.append_key_value("model", car.model);
+  builder.append_comma();
+  builder.append_key_value("year", car.year);
+  builder.append_comma();
+  builder.append_key_value("tire_pressure", car.tire_pressure);
+  builder.end_object();
+}
+
+} // namespace simdjson
+```
+
+C++26 static reflection
+------------------------
+
+Static reflection (or compile-time reflection) in C++26 introduces a powerful compile-time mechanism that allows a program to inspect and manipulate its own structure, such as types, variables, functions, and other program elements, during compilation. Unlike runtime reflection in languages like Java or Python, C++26’s static reflection operates entirely at compile time, aligning with C++’s emphasis on zero-overhead abstractions and high performance. It means
+that you can delegate much of the work to the library.
+If you have a compiler with support C++26 static reflection, you can compile
+your code with the `SIMDJSON_STATIC_REFLECTION` macro set:
+
+```cpp
+#define SIMDJSON_STATIC_REFLECTION 1
+//...
+#include "simdjson.h"
+```
+
+And then you can append your data structures to a `string_builder` instance
+automatically. In most cases, it should work automatically:
+
+```cpp
+    struct Car {
+        std::string make;
+        std::string model;
+        int64_t year;
+        std::vector<double> tire_pressure;
+    };
+
+    bool car_test() {
+        simdjson::builder::string_builder sb;
+        Car c = {"Toyota", "Corolla", 2017, {30.0,30.2,30.513,30.79}};
+        sb << c;
+        std::string_view p{sb};
+        // p holds the JSON:
+        // "{\"make\":\"Toyota\",\"model\":\"Corolla\",\"year\":2017,\"tire_pressure\":[30.0,30.2,30.513,30.79]}"
+        return true;
+    }
+```
+
+
+### Without `string_buffer` instance
+
+In some instances, you might want to create a string directly from your own data type.
+You can create a string directly, without an explicit `string_builder` instance
+with the `simdjson::to_json` template function.
+(Under the hood a `string_builder` instance may still be created.)
+
+```cpp
+    struct Car {
+        std::string make;
+        std::string model;
+        int64_t year;
+        std::vector<double> tire_pressure;
+    };
+
+    void f() {
+        Car c = {"Toyota", "Corolla", 2017, {30.0,30.2,30.513,30.79}};
+        std::string json = simdjson::to_json(c);
+    }
+```
+
+If you know the output size, in bytes, of your JSON string, you may
+pass it as a second parameter (e.g., `simdjson::to_json(c, 31123)`).
+
+Sometimes you may want to reuse the same `std::string` instance. We
+have an overload for this purpose:
+
+```cpp
+Car c = {"Toyota", "Corolla", 2017, {30.0,30.2,30.513,30.79}};
+std::string s;
+auto error = simdjson::to_json(c, s);
+if(error) { /* there was an error */ }
+```
+
+You can then also add a third parameter for the expected output size in bytes.
+
+### Extracting just some fields
+In some instances, your class might have many fields that you do not want to serialize.
+You can achieve this result with the `simdjson::extract_from` template. In the following
+example, we serialize only the `year` and `price` fields on the `Car` instance.
+```cpp
+struct Car {
+    std::string make;
+    std::string model;
+    int year;
+    double price;
+    bool electric;
+};
+Car car{"Ford", "F-150", 2024, 55000.0, false};
+// Extract year and price
+std::string json_result = simdjson::extract_from<"year", "price">(car);
+// Alternatively:
+// std::string json_result;
+// auto error =  extract_from<"year", "price">(car).get(json_result);
+// if(error) { /* error handling */ }
+```
+
+### Without `string_buffer` instance but with explicit error handling
+
+If prefer a version without exceptions and explicit error handling, you can use the following
+pattern:
+
+```cpp
+  std::string json;
+  if(simdjson::to_json(c).get(json)) {
+    // there was an error
+  } else {
+    // json contain the serialized JSON
+  }
+```
+
+### Customization
+
+If you want to serialize a value in a custome way, you can do it with a
+`tag_invoke` specialization like the following example which will map
+the year attribute to a string.
+
+
+```cpp
+#include <simdjson>
+
+struct Car {
+  std::string make;
+  std::string model;
+  int64_t year;
+  std::vector<float> tire_pressure;
+};
+
+namespace simdjson {
+
+template <typename builder_type>
+void tag_invoke(serialize_tag, builder_type &builder, const Car& car) {
+  builder.start_object();
+  builder.append_key_value("make", car.make);
+  builder.append_comma();
+  builder.append_key_value("model", car.model);
+  builder.append_comma();
+  builder.append_key_value("year", std::to_string(car.year));
+  builder.append_comma();
+  builder.append_key_value("tire_pressure", car.tire_pressure);
+  builder.end_object();
+}
+
+} // namespace simdjson
+```

doc/dom.md

@@ -1,12 +1,16 @@
 The Document-Object-Model (DOM) front-end
 ==========
 
-An overview of what you need to know to use simdjson, with examples.
+An overview of what you need to know to use simdjson to parse JSON documents with
+our DOM API, with examples. [Our documentation regarding the generation (serialization) of JSON documents is in a
+separate document](https://github.com/simdjson/simdjson/blob/master/doc/builder.md).
+
 
 * [DOM vs On-Demand](#dom-vs-on-demand)
 * [The Basics: Loading and Parsing JSON Documents](#the-basics-loading-and-parsing-json-documents-using-the-dom-front-end)
 * [Using the Parsed JSON](#using-the-parsed-json)
 * [C++17 Support](#c17-support)
+* [C++20 Support](#c20-support)
 * [JSON Pointer](#json-pointer)
 * [JSONPath](#jsonpath)
 * [Error Handling](#error-handling)
@@ -27,6 +31,10 @@ a conventional Document-Object-Model (DOM) front-end. In such a scenario, the JS
 entirely parsed, validated and materialized in memory as the first step. The programmer may
 then access the parsed data using this in-memory model.
 
+On-Demand is a different model where you parse just what you need, directly into your own
+data structure. The On-Demand approach, when well tuned, can provide superior performance.
+[We refer you to the On-Demand documentation for further details](https://github.com/simdjson/simdjson/blob/master/doc/basics.md).
+
 The Basics: Loading and Parsing JSON Documents using the DOM front-end
 ----------------------------------------------
 
@@ -90,7 +98,7 @@ During the`load` or `parse` calls, neither the input file nor the input string a
 For best performance, a `parser` instance should be reused over several files: otherwise you will needlessly reallocate memory, an expensive process. It is also possible to avoid entirely memory allocations during parsing when using simdjson. [See our performance notes for details](performance.md).
 
 If you need a lower-level interface, you may call the function `parser.parse(const char * p, size_t l)` on a pointer `p` while specifying the
-length of your input `l` in bytes. To see how to get the very best performance from a low-level approach, you way want to read our [performance notes](https://github.com/simdjson/simdjson/blob/master/doc/performance.md#padding-and-temporary-copies) on this topic (see the Padding and Temporary Copies section).
+length of your input `l` in bytes.
 
 *Windows-specific*:  Windows users who need to read files with
 non-ANSI characters in the name should set their code page to
@@ -119,6 +127,12 @@ Once you have an element, you can navigate it with idiomatic C++ iterators, oper
   std::cout << "I parsed " << value << " from " << numberstring.data() << std::endl;
   ```
   The strings contain unescaped valid UTF-8 strings: no unmatched surrogate is allowed.
+  Internally, numbers are stored as either 64-bit integers or 64-bit floating-point numbers.
+  Thus it is possible to get the full 64-bit integer range (either signed or  unsigned).
+  By default, the string `-0` is parsed as the integer 0 as in Python or C++. If you set the macro
+  `SIMDJSON_MINUS_ZERO_AS_FLOAT` to `1` when building simdjson, you can get that `-0` is mapped to `-0.0`
+  as in JavaScript. You can get the desired effect by building simdjson with cmake setting the
+  `SIMDJSON_MINUS_ZERO_AS_FLOAT` to on: `cmake -B build -D SIMDJSON_MINUS_ZERO_AS_FLOAT=ON`.
 * **Field Access:** To get the value of the "foo" field in an object, use `object["foo"]`.
 * **Array Iteration:** To iterate through an array, use `for (auto value : array) { ... }`. If you
   know the type of the value, you can cast it right there, too! `for (double value : array) { ... }`
@@ -232,6 +246,23 @@ for (dom::key_value_pair field : object) {
 }
 ```
 
+C++20 Support
+------------
+
+simdjson library also supports some C++20 feature including `std::ranges`:
+
+```c++
+auto cars_json = R"( [
+  { "make": "Toyota", "model": "Camry",  "year": 2018, "tire_pressure": [ 40.1, 39.9, 37.7, 40.4 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012, "tire_pressure": [ 30.1, 31.0, 28.6, 28.7 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999, "tire_pressure": [ 29.8, 30.0, 30.2, 30.5 ] }
+] )"_padded;
+dom::parser parser;
+auto justmodel = [](auto car) { return car["model"]; };
+for (auto car : parser.parse(cars_json).get_array() | std::views::transform(justmodel)) {
+  std::cout << car << std::endl;
+}
+```
 
 JSON Pointer
 ------------
@@ -323,6 +354,74 @@ if(error) { /*won't happen*/ }
 ```
 
 
+## Using `at_path_with_wildcard` for JSONPath Queries
+
+The `at_path_with_wildcard` function in simdjson extends the JSONPath querying capabilities by supporting wildcard expressions (`*`) in JSON paths. This allows users to retrieve multiple elements from a JSON document in a single query. For example, you can use `$.address.*` to fetch all fields within the `address` object or `$.phoneNumbers[*].numbers[*]` to retrieve all phone numbers across multiple objects in an array.
+
+The `*` wildcard matches all elements at a specific level. For instance, `$.address.*` retrieves all key-value pairs in the `address` object, while `$.*.streetAddress` fetches all `streetAddress` fields across objects at the root level.  You can combine wildcards with array indexing. For example, `$.phoneNumbers[*].numbers[1]` retrieves the second number from each `numbers` array in the `phoneNumbers` array. If no elements match the wildcard query, the function returns an empty result. For instance, querying `$.empty_object.*` or `$.empty_array.*` will yield an empty set.
+
+### Example Usage
+
+Here is an example demonstrating the use of `at_path_with_wildcard`:
+
+```cpp
+simdjson::padded_string json_string = R"(
+{
+  "firstName": "John",
+  "lastName": "doe",
+  "age": 26,
+  "address": {
+    "streetAddress": "naist street",
+    "city": "Nara",
+    "postalCode": "630-0192"
+  },
+  "phoneNumbers": [
+    {
+      "type": "iPhone",
+      "numbers": ["0123-4567-8888", "0123-4567-8788"]
+    },
+    {
+      "type": "home",
+      "numbers": ["0123-4567-8910"]
+    }
+  ]
+})"_padded;
+
+dom::parser parser;
+dom::element parsed_json = parser.parse(json_string);
+std::vector<dom::element> values;
+
+// Fetch all fields in the address object
+auto error = parsed_json.at_path_with_wildcard("$.address.*").get(values);
+if(error) {
+  // do something
+}
+for (auto &value : values) {
+  std::string_view field;
+  error = value.get(field);
+  if(error) {
+    // do something
+  }
+  std::cout << field << std::endl;
+}
+
+// Fetch all phone numbers
+error = parsed_json.at_path_with_wildcard("$.phoneNumbers[*].numbers[*]").get(values);
+if(error) {
+  // do something
+}
+for (auto &value : values) {
+  std::string_view number;
+  error = value.get(number);
+  if(error) {
+    // do something
+  }
+  std::cout << number << std::endl;
+}
+```
+
+This function is particularly useful for extracting data from complex JSON structures with nested arrays and objects. By leveraging wildcards, you can simplify your queries and reduce the need for multiple iterations.
+
 Error Handling
 --------------
 

doc/iterate_many.md

@@ -309,7 +309,7 @@ The first argument is usually a tag type (often an empty struct) that uniquely i
 
 
 You can deserialize you own data structures conveniently if your system supports C++20.
-When it is the case, the macro `SIMDJSON_SUPPORTS_DESERIALIZATION` will be set to 1 by
+When it is the case, the macro `SIMDJSON_SUPPORTS_CONCEPTS` will be set to 1 by
 the simdjson library.
 
 Consider a custom class `Car`:

doc/performance.md

@@ -4,9 +4,9 @@ Performance Notes
 simdjson strives to be at its fastest *without tuning*, and generally achieves this. However, there
 are still some scenarios where tuning can enhance performance.
 Once your code is tested, we
-further encourage you to define `NDEBUG` in your Release builds to disable additional runtime
+further encourage you to define `NDEBUG` in your release builds to disable additional runtime
 testing and get the best performance.
-* [NDEBUG directive](#ndebug-directive)
+* [NDEBUG macro](#ndebug-macro)
 * [Reusing the parser for maximum efficiency](#reusing-the-parser-for-maximum-efficiency)
 * [Reusing string buffers](#reusing-string-buffers)
 * [Server Loops: Long-Running Processes and Memory Capacity](#server-loops-long-running-processes-and-memory-capacity)
@@ -17,16 +17,27 @@ testing and get the best performance.
 * [Free Padding](#free-padding)
 
 
-NDEBUG directive
+NDEBUG macro
 -------------
 
-In C/C++, the `NDEBUG` pre-processor directive is not set by default. When it is not set, the simdjson library does
-many additional checks that may impact negatively the performance. We recommend that, once your code
-is well tested, you define `NDEBUG` directive in your Release builds. The `NDEBUG` directive should be defined
-prior to including the `simdjson.h` header.
+We recommend that you set `NDEBUG` macro in your release builds.
 
-The `NDEBUG` directive is generally independent from optimization flags. For example, setting `-O3` under
-GCC does not set the `NDEBUG` directive.
+In C/C++, the `NDEBUG` macro is not set by default.
+When it is not set, the software may do many additional checks that may impact
+negatively the performance. We recommend that, once your code
+is well tested, you define `NDEBUG` directive in your release builds.
+
+The `NDEBUG` directive is generally independent from optimization flags.
+For example, setting `-O3` under GCC does not set the `NDEBUG` directive.
+However, tools like `CMake` automatically
+set `NDEBUG` for release builds.
+
+In the simdjson library, we check the `NDEBUG` macro as well as other
+macros to make performant release builds. However, the C++ standard
+does not provide a definitive approach to determine whether you are
+compiling for a release build. Thus we recommend that you follow
+the practice of setting the `NDEBUG` macro in release mode to make sure
+that you do not get undesirable expensive checks.
 
 Reusing the parser for maximum efficiency
 -----------------------------------------
@@ -162,8 +173,6 @@ Recent versions of Microsoft Visual Studio on Windows provides support for the L
 
 We recommend Visual Studio users prefer LLVM (clang-cl). It compiles to faster release binaries. Furthermore, it compilers faster in release mode.
 
-Under Windows, we also support the GNU GCC compiler via MSYS2. The performance of 64-bit MSYS2 under Windows is excellent (on par with Linux).
-
 
 Power Usage and Downclocking
 --------------
@@ -244,7 +253,7 @@ long page_size() {
 // page boundary.
 bool need_allocation(const char *buf, size_t len) {
   return ((reinterpret_cast<uintptr_t>(buf + len - 1) % page_size())
-    + simdjson::SIMDJSON_PADDING > static_cast<uintptr_t>(page_size()));
+    + simdjson::SIMDJSON_PADDING >= static_cast<uintptr_t>(page_size()));
 }
 
 simdjson::padded_string_view

examples/quickstart/CMakeLists.txt

@@ -20,10 +20,14 @@ IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
   endif()
 
   add_quickstart_test(quickstart_noexceptions   quickstart_noexceptions.cpp NO_EXCEPTIONS LABELS acceptance)
-  add_quickstart_test(quickstart_noexceptions11 quickstart_noexceptions.cpp NO_EXCEPTIONS CXX_STANDARD c++11)
+  if(NOT SIMDJSON_STATIC_REFLECTION)
+    add_quickstart_test(quickstart_noexceptions11 quickstart_noexceptions.cpp NO_EXCEPTIONS CXX_STANDARD c++11)
+  endif(NOT SIMDJSON_STATIC_REFLECTION)
 
   add_quickstart_test(quickstart2_noexceptions   quickstart2_noexceptions.cpp NO_EXCEPTIONS LABELS acceptance)
-  add_quickstart_test(quickstart2_noexceptions11 quickstart2_noexceptions.cpp NO_EXCEPTIONS CXX_STANDARD c++11)
+  if(NOT SIMDJSON_STATIC_REFLECTION)
+    add_quickstart_test(quickstart2_noexceptions11 quickstart2_noexceptions.cpp NO_EXCEPTIONS CXX_STANDARD c++11)
+  endif(NOT SIMDJSON_STATIC_REFLECTION)
 
   # On-Demand Quick Start
   if (SIMDJSON_EXCEPTIONS)
@@ -33,6 +37,8 @@ IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
   endif()
 
   add_quickstart_test(quickstart_ondemand_noexceptions   quickstart_ondemand_noexceptions.cpp NO_EXCEPTIONS LABELS quickstart_ondemand acceptance)
-  add_quickstart_test(quickstart_ondemand_noexceptions11 quickstart_ondemand_noexceptions.cpp NO_EXCEPTIONS CXX_STANDARD c++11 LABELS quickstart_ondemand)
+  if(NOT SIMDJSON_STATIC_REFLECTION)
+    add_quickstart_test(quickstart_ondemand_noexceptions11 quickstart_ondemand_noexceptions.cpp NO_EXCEPTIONS CXX_STANDARD c++11 LABELS quickstart_ondemand)
+  endif(NOT SIMDJSON_STATIC_REFLECTION)
 
 endif()

fuzz/fuzz_minify.cpp

@@ -18,7 +18,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
     auto error = parser.parse(str).get(elem);
     if (error) { return 0; }
 
-    std::string minified=simdjson::minify(elem);
+    std::string minified = simdjson::minify(elem);
     (void)minified;
     return 0;
 }

include/simdjson.h

@@ -53,4 +53,6 @@
 
 #include "simdjson/dom.h"
 #include "simdjson/ondemand.h"
+#include "simdjson/convert.h"
+#include "simdjson/convert-inl.h"
 #endif // SIMDJSON_H

include/simdjson/arm64/simd.h

@@ -134,6 +134,12 @@ namespace {
       tmp = vpaddq_u8(tmp, tmp);
       return vgetq_lane_u16(vreinterpretq_u16_u8(tmp), 0);
     }
+    // Returns 4-bit out of each byte, alternating between the high 4 bits and low
+    // bits result it is 64 bit.
+    simdjson_inline uint64_t to_bitmask64() const {
+      return vget_lane_u64(
+          vreinterpret_u64_u8(vshrn_n_u16(vreinterpretq_u16_u8(*this), 4)), 0);
+    }
     simdjson_inline bool any() const { return vmaxvq_u32(vreinterpretq_u32_u8(*this)) != 0; }
   };
 
@@ -210,7 +216,7 @@ namespace {
 
     // Bit-specific operations
     simdjson_inline simd8<bool> any_bits_set(simd8<uint8_t> bits) const { return vtstq_u8(*this, bits); }
-    simdjson_inline bool any_bits_set_anywhere() const { return this->max_val() != 0; }
+    simdjson_inline bool any_bits_set_anywhere() const { return vmaxvq_u32(vreinterpretq_u32_u8(*this)) != 0; }
     simdjson_inline bool any_bits_set_anywhere(simd8<uint8_t> bits) const { return (*this & bits).any_bits_set_anywhere(); }
     template<int N>
     simdjson_inline simd8<uint8_t> shr() const { return vshrq_n_u8(*this, N); }
@@ -223,7 +229,12 @@ namespace {
       return lookup_table.apply_lookup_16_to(*this);
     }
 
-
+    // Returns 4-bit out of each byte, alternating between the high 4 bits and low
+    // bits result it is 64 bit.
+    simdjson_inline uint64_t to_bitmask64() const {
+      return vget_lane_u64(
+          vreinterpret_u64_u8(vshrn_n_u16(vreinterpretq_u16_u8(*this), 4)), 0);
+    }
     // Copies to 'output" all bytes corresponding to a 0 in the mask (interpreted as a bitset).
     // Passing a 0 value for mask would be equivalent to writing out every byte to output.
     // Only the first 16 - count_ones(mask) bytes of the result are significant but 16 bytes

include/simdjson/arm64/stringparsing_defs.h

@@ -17,7 +17,7 @@ using namespace simd;
 struct backslash_and_quote {
 public:
   static constexpr uint32_t BYTES_PROCESSED = 32;
-  simdjson_inline static backslash_and_quote copy_and_find(const uint8_t *src, uint8_t *dst);
+  simdjson_inline backslash_and_quote copy_and_find(const uint8_t *src, uint8_t *dst);
 
   simdjson_inline bool has_quote_first() { return ((bs_bits - 1) & quote_bits) != 0; }
   simdjson_inline bool has_backslash() { return bs_bits != 0; }
@@ -46,6 +46,32 @@ simdjson_inline backslash_and_quote backslash_and_quote::copy_and_find(const uin
   };
 }
 
+struct escaping {
+  static constexpr uint32_t BYTES_PROCESSED = 16;
+  simdjson_inline static escaping copy_and_find(const uint8_t *src, uint8_t *dst);
+
+  simdjson_inline bool has_escape() { return escape_bits != 0; }
+  simdjson_inline int escape_index() { return trailing_zeroes(escape_bits) / 4; }
+
+  uint64_t escape_bits;
+}; // struct escaping
+
+
+
+simdjson_inline escaping escaping::copy_and_find(const uint8_t *src, uint8_t *dst) {
+  static_assert(SIMDJSON_PADDING >= (BYTES_PROCESSED - 1), "escaping finder must process fewer than SIMDJSON_PADDING bytes");
+  simd8<uint8_t> v(src);
+  v.store(dst);
+  simd8<bool> is_quote = (v == '"');
+  simd8<bool> is_backslash = (v == '\\');
+  simd8<bool> is_control = (v < 32);
+  return {
+    (is_backslash | is_quote | is_control).to_bitmask64()
+  };
+}
+
+
+
 } // unnamed namespace
 } // namespace arm64
 } // namespace simdjson

include/simdjson/base.h

@@ -10,6 +10,7 @@
 #include "simdjson/error.h"
 #include "simdjson/portability.h"
 #include "simdjson/concepts.h"
+#include "simdjson/constevalutil.h"
 
 /**
  * @brief The top level simdjson namespace, containing everything the library provides.

include/simdjson/common_defs.h

@@ -23,7 +23,7 @@ double from_chars(const char *first, const char* end) noexcept;
 }
 
 #ifndef SIMDJSON_EXCEPTIONS
-#if __cpp_exceptions
+#if defined(__cpp_exceptions) || defined(_CPPUNWIND)
 #define SIMDJSON_EXCEPTIONS 1
 #else
 #define SIMDJSON_EXCEPTIONS 0
@@ -199,17 +199,6 @@ double from_chars(const char *first, const char* end) noexcept;
     // We assume by default static linkage
     #define SIMDJSON_DLLIMPORTEXPORT
     #endif
-
-/**
- * Workaround for the vcpkg package manager. Only vcpkg should
- * ever touch the next line. The SIMDJSON_USING_LIBRARY macro is otherwise unused.
- */
-#if SIMDJSON_USING_LIBRARY
-#define SIMDJSON_DLLIMPORTEXPORT __declspec(dllimport)
-#endif
-/**
- * End of workaround for the vcpkg package manager.
- */
 #else
     #define SIMDJSON_DLLIMPORTEXPORT
 #endif
@@ -226,12 +215,14 @@ double from_chars(const char *first, const char* end) noexcept;
 // even if we do not have C++17 support.
 #ifdef __cpp_lib_string_view
 #define SIMDJSON_HAS_STRING_VIEW
+#include <string_view>
 #endif
 
 // Some systems have string_view even if we do not have C++17 support,
 // and even if __cpp_lib_string_view is undefined, it is the case
 // with Apple clang version 11.
 // We must handle it. *This is important.*
+#ifndef _MSC_VER
 #ifndef SIMDJSON_HAS_STRING_VIEW
 #if defined __has_include
 // do not combine the next #if with the previous one (unsafe)
@@ -247,6 +238,7 @@ double from_chars(const char *first, const char* end) noexcept;
 #endif // __has_include (<string_view>)
 #endif // defined __has_include
 #endif // def SIMDJSON_HAS_STRING_VIEW
+#endif // def _MSC_VER
 // end of complicated but important routine to try to detect string_view.
 
 //
@@ -279,16 +271,25 @@ namespace std {
 // It could also wrongly set SIMDJSON_DEVELOPMENT_CHECKS (e.g., if the programmer
 // sets _DEBUG in a release build under Visual Studio, or if some compiler fails to
 // set the __OPTIMIZE__ macro).
+// We make it so that if NDEBUG is defined, then SIMDJSON_DEVELOPMENT_CHECKS
+// is not defined, irrespective of the compiler.
+// We recommend that users set NDEBUG in release builds, so that
+// SIMDJSON_DEVELOPMENT_CHECKS is not defined in release builds by default,
+// irrespective of the compiler.
 #ifndef SIMDJSON_DEVELOPMENT_CHECKS
 #ifdef _MSC_VER
 // Visual Studio seems to set _DEBUG for debug builds.
-#ifdef _DEBUG
+// We set SIMDJSON_DEVELOPMENT_CHECKS to 1 if _DEBUG is defined
+// and NDEBUG is not defined.
+#if defined(_DEBUG) && !defined(NDEBUG)
 #define SIMDJSON_DEVELOPMENT_CHECKS 1
 #endif // _DEBUG
 #else // _MSC_VER
 // All other compilers appear to set __OPTIMIZE__ to a positive integer
 // when the compiler is optimizing.
-#ifndef __OPTIMIZE__
+// We only set SIMDJSON_DEVELOPMENT_CHECKS if both __OPTIMIZE__
+// and NDEBUG are not defined.
+#if !defined(__OPTIMIZE__) && !defined(NDEBUG)
 #define SIMDJSON_DEVELOPMENT_CHECKS 1
 #endif // __OPTIMIZE__
 #endif // _MSC_VER
@@ -344,4 +345,16 @@ namespace std {
 #define SIMDJSON_AVX512_ALLOWED 1
 #endif
 
+
+#ifndef __has_cpp_attribute
+#define simdjson_lifetime_bound
+#elif __has_cpp_attribute(msvc::lifetimebound)
+#define simdjson_lifetime_bound [[msvc::lifetimebound]]
+#elif __has_cpp_attribute(clang::lifetimebound)
+#define simdjson_lifetime_bound [[clang::lifetimebound]]
+#elif __has_cpp_attribute(lifetimebound)
+#define simdjson_lifetime_bound [[lifetimebound]]
+#else
+#define simdjson_lifetime_bound
+#endif
 #endif // SIMDJSON_COMMON_DEFS_H

include/simdjson/compiler_check.h

@@ -50,28 +50,69 @@
 #endif
 #endif
 
+#ifndef SIMDJSON_CONSTEXPR_LAMBDA
+#if SIMDJSON_CPLUSPLUS17
+#define SIMDJSON_CONSTEXPR_LAMBDA constexpr
+#else
+#define SIMDJSON_CONSTEXPR_LAMBDA
+#endif
+#endif
+
+
+
 #ifdef __has_include
 #if __has_include(<version>)
 #include <version>
 #endif
 #endif
 
+// The current specification is unclear on how we detect
+// static reflection, both __cpp_lib_reflection and
+// __cpp_impl_reflection are proposed in the draft specification.
+// For now, we disable static reflect by default. It must be
+// specified at compiler time.
+#ifndef SIMDJSON_STATIC_REFLECTION
+#define SIMDJSON_STATIC_REFLECTION 0 // disabled by default.
+#endif
+
 #if defined(__apple_build_version__)
 #if __apple_build_version__ < 14000000
 #define SIMDJSON_CONCEPT_DISABLED 1 // apple-clang/13 doesn't support std::convertible_to
 #endif
 #endif
 
+#if defined(__cpp_lib_ranges) && __cpp_lib_ranges >= 201911L
+#include <ranges>
+#define SIMDJSON_SUPPORTS_RANGES 1
+#else
+#define SIMDJSON_SUPPORTS_RANGES 0
+#endif
 
 #if defined(__cpp_concepts) && !defined(SIMDJSON_CONCEPT_DISABLED)
 #if __cpp_concepts >= 201907L
 #include <utility>
+#define SIMDJSON_SUPPORTS_CONCEPTS 1
+#else
+#define SIMDJSON_SUPPORTS_CONCEPTS 0
+#endif
+#else // defined(__cpp_concepts) && !defined(SIMDJSON_CONCEPT_DISABLED)
+#define SIMDJSON_SUPPORTS_CONCEPTS 0
+#endif // defined(__cpp_concepts) && !defined(SIMDJSON_CONCEPT_DISABLED)
+
+// copy SIMDJSON_SUPPORTS_CONCEPTS to SIMDJSON_SUPPORTS_DESERIALIZATION.
+#if SIMDJSON_SUPPORTS_CONCEPTS
 #define SIMDJSON_SUPPORTS_DESERIALIZATION 1
 #else
 #define SIMDJSON_SUPPORTS_DESERIALIZATION 0
 #endif
-#else // defined(__cpp_concepts) && !defined(SIMDJSON_CONCEPT_DISABLED)
-#define SIMDJSON_SUPPORTS_DESERIALIZATION 0
-#endif // defined(__cpp_concepts) && !defined(SIMDJSON_CONCEPT_DISABLED)
+
+
+#if !defined(SIMDJSON_CONSTEVAL)
+#if defined(__cpp_consteval) && __cpp_consteval >= 201811L && defined(__cpp_lib_constexpr_string) && __cpp_lib_constexpr_string >= 201907L
+#define SIMDJSON_CONSTEVAL 1
+#else
+#define SIMDJSON_CONSTEVAL 0
+#endif // defined(__cpp_consteval) && __cpp_consteval >= 201811L && defined(__cpp_lib_constexpr_string) && __cpp_lib_constexpr_string >= 201907L
+#endif // !defined(SIMDJSON_CONSTEVAL)
 
 #endif // SIMDJSON_COMPILER_CHECK_H

include/simdjson/concepts.h

@@ -1,6 +1,6 @@
 #ifndef SIMDJSON_CONCEPTS_H
 #define SIMDJSON_CONCEPTS_H
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
 
 #include <concepts>
 #include <type_traits>
@@ -32,7 +32,9 @@ SIMDJSON_IMPL_CONCEPT(op_append, operator+=)
 #undef SIMDJSON_IMPL_CONCEPT
 } // namespace details
 
-
+template <typename T>
+concept is_pair = requires { typename T::first_type; typename T::second_type; } &&
+                  std::same_as<T, std::pair<typename T::first_type, typename T::second_type>>;
 template <typename T>
 concept string_view_like = std::is_convertible_v<T, std::string_view> &&
                            !std::is_convertible_v<T, const char*>;
@@ -115,17 +117,51 @@ concept optional_type = requires(std::remove_cvref_t<T> obj) {
   { obj.value() } -> std::same_as<typename std::remove_cvref_t<T>::value_type&>;
   requires requires(typename std::remove_cvref_t<T>::value_type &&val) {
     obj.emplace(std::move(val));
-    obj = std::move(val);
     {
       obj.value_or(val)
     } -> std::convertible_to<typename std::remove_cvref_t<T>::value_type>;
   };
   { static_cast<bool>(obj) } -> std::same_as<bool>; // convertible to bool
+  { obj.reset() } noexcept -> std::same_as<void>;
 };
 
 
 
+// Types we serialize as JSON strings (not as containers)
+template <typename T>
+concept string_like =
+  std::is_same_v<std::remove_cvref_t<T>, std::string> ||
+  std::is_same_v<std::remove_cvref_t<T>, std::string_view> ||
+  std::is_same_v<std::remove_cvref_t<T>, const char*> ||
+  std::is_same_v<std::remove_cvref_t<T>, char*>;
+
+// Concept that checks if a type is a container but not a string (because
+// strings handling must be handled differently)
+// Now uses iterator-based approach for broader container support
+template <typename T>
+concept container_but_not_string =
+  std::ranges::input_range<T> && !string_like<T> && !concepts::string_view_keyed_map<T>;
+
+
 } // namespace concepts
+
+
+/**
+ * We use tag_invoke as our customization point mechanism.
+ */
+template <typename Tag, typename... Args>
+concept tag_invocable = requires(Tag tag, Args... args) {
+  tag_invoke(std::forward<Tag>(tag), std::forward<Args>(args)...);
+};
+
+template <typename Tag, typename... Args>
+concept nothrow_tag_invocable =
+    tag_invocable<Tag, Args...> && requires(Tag tag, Args... args) {
+      {
+        tag_invoke(std::forward<Tag>(tag), std::forward<Args>(args)...)
+      } noexcept;
+    };
+
 } // namespace simdjson
-#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
 #endif // SIMDJSON_CONCEPTS_H

include/simdjson/constevalutil.h

@@ -0,0 +1,75 @@
+#ifndef SIMDJSON_CONSTEVALUTIL_H
+#define SIMDJSON_CONSTEVALUTIL_H
+
+#include <string>
+#include <string_view>
+#include <array>
+
+namespace simdjson {
+namespace constevalutil {
+#if SIMDJSON_CONSTEVAL
+
+constexpr static std::array<uint8_t, 256> json_quotable_character = {
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+constexpr static std::array<std::string_view, 32> control_chars = {
+    "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006",
+    "\\u0007", "\\b", "\\t",     "\\n",     "\\u000b", "\\f",     "\\r",
+    "\\u000e", "\\u000f", "\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014",
+    "\\u0015", "\\u0016", "\\u0017", "\\u0018", "\\u0019", "\\u001a", "\\u001b",
+    "\\u001c", "\\u001d", "\\u001e", "\\u001f"};
+// unoptimized, meant for compile-time execution
+consteval std::string consteval_to_quoted_escaped(std::string_view input) {
+  std::string out = "\"";
+  for (char c : input) {
+    if (json_quotable_character[uint8_t(c)]) {
+      if (c == '"') {
+        out.append("\\\"");
+      } else if (c == '\\') {
+        out.append("\\\\");
+      } else {
+        std::string_view v = control_chars[uint8_t(c)];
+        out.append(v);
+      }
+    } else {
+      out.push_back(c);
+    }
+  }
+  out.push_back('"');
+  return out;
+}
+#endif  // SIMDJSON_CONSTEVAL
+
+
+#if SIMDJSON_SUPPORTS_CONCEPTS
+template <std::size_t N>
+struct fixed_string {
+    constexpr fixed_string(const char (&str)[N])  {
+        for (std::size_t i = 0; i < N; ++i) {
+            data[i] = str[i];
+        }
+    }
+    char data[N];
+    constexpr std::string_view view() const { return {data, N - 1}; }
+};
+template <std::size_t N>
+fixed_string(const char (&)[N]) -> fixed_string<N>;
+
+template <fixed_string str>
+struct string_constant {
+    static constexpr std::string_view value = str.view();
+};
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
+
+} // namespace constevalutil
+} // namespace simdjson
+#endif // SIMDJSON_CONSTEVALUTIL_H

include/simdjson/convert-inl.h

@@ -0,0 +1,135 @@
+
+#ifndef SIMDJSON_CONVERT_INL_H
+#define SIMDJSON_CONVERT_INL_H
+
+#include "simdjson/convert.h"
+#if SIMDJSON_SUPPORTS_CONCEPTS
+namespace simdjson {
+namespace convert {
+namespace internal {
+// auto_parser method definitions
+template <typename parser_type>
+inline auto_parser<parser_type>::auto_parser(parser_type &&parser, ondemand::document &&doc) noexcept requires(!std::is_pointer_v<parser_type>)
+  : m_parser{std::move(parser)}, m_doc{std::move(doc)} {}
+
+template <typename parser_type>
+inline auto_parser<parser_type>::auto_parser(parser_type &&parser, padded_string_view const str) noexcept requires(!std::is_pointer_v<parser_type>)
+  : m_parser{std::move(parser)}, m_doc{}, m_error{SUCCESS} {
+  m_error = m_parser.iterate(str).get(m_doc);
+}
+
+template <typename parser_type>
+inline auto_parser<parser_type>::auto_parser(std::remove_pointer_t<parser_type> &parser, ondemand::document &&doc) noexcept requires(std::is_pointer_v<parser_type>)
+  : m_parser{&parser}, m_doc{std::move(doc)} {}
+
+template <typename parser_type>
+inline auto_parser<parser_type>::auto_parser(std::remove_pointer_t<parser_type> &parser, padded_string_view const str) noexcept requires(std::is_pointer_v<parser_type>)
+  : m_parser{&parser}, m_doc{}, m_error{SUCCESS} {
+  m_error = m_parser->iterate(str).get(m_doc);
+}
+
+template <typename parser_type>
+inline auto_parser<parser_type>::auto_parser(padded_string_view const str) noexcept requires(std::is_pointer_v<parser_type>)
+  : auto_parser{ondemand::parser::get_parser(), str} {}
+
+template <typename parser_type>
+inline auto_parser<parser_type>::auto_parser(parser_type parser, ondemand::document &&doc) noexcept requires(std::is_pointer_v<parser_type>)
+  : auto_parser{*parser, std::move(doc)} {}
+
+
+
+
+
+template <typename parser_type>
+inline std::remove_pointer_t<parser_type> &auto_parser<parser_type>::parser() noexcept {
+  if constexpr (std::is_pointer_v<parser_type>) {
+    return *m_parser;
+  } else {
+    return m_parser;
+  }
+}
+
+template <typename parser_type>
+template <typename T>
+inline simdjson_result<T> auto_parser<parser_type>::result() noexcept(is_nothrow_gettable<T>) {
+  if (m_error != SUCCESS) {
+    return m_error;
+  }
+  return m_doc.get<T>();
+}
+
+template <typename parser_type>
+template <typename T>
+simdjson_warn_unused simdjson_inline error_code auto_parser<parser_type>::get(T &value) && noexcept(is_nothrow_gettable<T>) {
+  return result<T>().get(value);
+}
+
+template <typename parser_type>
+inline simdjson_result<ondemand::array> auto_parser<parser_type>::array() noexcept {
+  return result<ondemand::array>();
+}
+
+template <typename parser_type>
+inline simdjson_result<ondemand::object> auto_parser<parser_type>::object() noexcept {
+  return result<ondemand::object>();
+}
+
+template <typename parser_type>
+inline simdjson_result<ondemand::number> auto_parser<parser_type>::number() noexcept {
+  return result<ondemand::number>();
+}
+
+#if SIMDJSON_EXCEPTIONS
+template <typename parser_type>
+template <typename T>
+inline auto_parser<parser_type>::operator T() noexcept(false) {
+  if (m_error != SUCCESS) {
+    throw simdjson_error(m_error);
+  }
+  return m_doc.get<T>();
+}
+#endif // SIMDJSON_EXCEPTIONS
+
+template <typename parser_type>
+template <typename T>
+inline std::optional<T> auto_parser<parser_type>::optional() noexcept(is_nothrow_gettable<T>) {
+  if (m_error != SUCCESS) {
+    return std::nullopt;
+  }
+  T value;
+  if (m_doc.get<T>().get(value)) [[unlikely]] {
+    return std::nullopt;
+  }
+  return {std::move(value)};
+}
+
+// to_adaptor method definitions
+template <typename T>
+inline T to_adaptor<T>::operator()(simdjson_result<ondemand::value> &val) const noexcept {
+  return val.get<T>();
+}
+
+template <typename T>
+inline auto to_adaptor<T>::operator()(padded_string_view const str) const noexcept {
+  return auto_parser<ondemand::parser *>{str};
+}
+
+template <typename T>
+inline auto to_adaptor<T>::operator()(ondemand::parser &parser, padded_string_view const str) const noexcept {
+  return auto_parser<ondemand::parser *>{parser, str};
+}
+
+template <typename T>
+inline auto to_adaptor<T>::operator()(std::string str) const noexcept {
+  return auto_parser<ondemand::parser *>{pad_with_reserve(str)};
+}
+
+template <typename T>
+inline auto to_adaptor<T>::operator()(ondemand::parser &parser, std::string str) const noexcept {
+  return auto_parser<ondemand::parser *>{parser, pad_with_reserve(str)};
+}
+} // namespace internal
+} // namespace convert
+} // namespace simdjson
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
+#endif // SIMDJSON_CONVERT_INL_H

include/simdjson/convert.h

@@ -0,0 +1,121 @@
+
+#ifndef SIMDJSON_CONVERT_H
+#define SIMDJSON_CONVERT_H
+
+#include "simdjson/ondemand.h"
+#include <optional>
+
+#if SIMDJSON_SUPPORTS_CONCEPTS
+
+
+namespace simdjson {
+namespace convert {
+namespace internal {
+
+/**
+ * A utility class for automatically parsing JSON documents.
+ * This template is NOT part of our public API.
+ * It is subject to changes.
+ * @private
+ */
+template <typename parser_type = ondemand::parser*>
+struct auto_parser {
+private:
+	parser_type m_parser;
+	ondemand::document m_doc;
+	error_code m_error{SUCCESS};
+
+	template <typename T>
+	static constexpr bool is_nothrow_gettable = requires(ondemand::document doc) {
+		{ doc.get<T>() } noexcept;
+	};
+public:
+	explicit auto_parser(parser_type &&parser, ondemand::document &&doc) noexcept requires(!std::is_pointer_v<parser_type>);
+	explicit auto_parser(parser_type &&parser, padded_string_view const str) noexcept requires(!std::is_pointer_v<parser_type>);
+	explicit auto_parser(std::remove_pointer_t<parser_type> &parser, ondemand::document &&doc) noexcept requires(std::is_pointer_v<parser_type>);
+	explicit auto_parser(std::remove_pointer_t<parser_type> &parser, padded_string_view const str) noexcept requires(std::is_pointer_v<parser_type>);
+	explicit auto_parser(padded_string_view const str) noexcept requires(std::is_pointer_v<parser_type>);
+	explicit auto_parser(parser_type parser, ondemand::document &&doc) noexcept requires(std::is_pointer_v<parser_type>);
+		auto_parser(auto_parser const &) = delete;
+		auto_parser &operator=(auto_parser const &) = delete;
+		auto_parser(auto_parser &&) noexcept = default;
+		auto_parser &operator=(auto_parser &&) noexcept = default;
+		~auto_parser() = default;
+
+	simdjson_warn_unused std::remove_pointer_t<parser_type> &parser() noexcept;
+
+	template <typename T>
+	simdjson_warn_unused simdjson_inline simdjson_result<T> result() noexcept(is_nothrow_gettable<T>);
+	template <typename T>
+	simdjson_warn_unused simdjson_inline error_code get(T &value) && noexcept(is_nothrow_gettable<T>);
+
+
+	simdjson_warn_unused simdjson_inline simdjson_result<ondemand::array> array() noexcept;
+	simdjson_warn_unused simdjson_inline simdjson_result<ondemand::object> object() noexcept;
+	simdjson_warn_unused simdjson_inline simdjson_result<ondemand::number> number() noexcept;
+
+
+#if SIMDJSON_EXCEPTIONS
+	template <typename T>
+	simdjson_warn_unused simdjson_inline explicit(false) operator T() noexcept(false);
+#endif // SIMDJSON_EXCEPTIONS
+
+	template <typename T>
+	simdjson_warn_unused simdjson_inline std::optional<T> optional() noexcept(is_nothrow_gettable<T>);
+};
+
+
+/**
+ * A utility class for adapting values for the `auto_parser`.
+ * This template is not part of our public API. It is subject to changes.
+ * @private
+ */
+template <typename T = void>
+struct to_adaptor {
+	T operator()(simdjson_result<ondemand::value> &val) const noexcept;
+	auto operator()(padded_string_view const str) const noexcept;
+	auto operator()(ondemand::parser &parser, padded_string_view const str) const noexcept;
+	// The std::string is padded with reserve to ensure there is enough space for padding.
+	// Some sanitizers may not like this, so you can use simdjson::pad instead.
+	// simdjson::from(simdjson::pad(str))
+	auto operator()(std::string str) const noexcept;
+	auto operator()(ondemand::parser &parser, std::string str) const noexcept;
+};
+// deduction guide
+auto_parser(padded_string_view const str) -> auto_parser<ondemand::parser*>;
+} // namespace internal
+} // namespace convert
+
+/**
+ * The simdjson::from instance is EXPERIMENTAL AND SUBJECT TO CHANGES.
+ *
+ * The `from` instance is a utility adaptor for parsing JSON strings into objects.
+ * It provides a convenient way to convert JSON data into C++ objects using the `auto_parser`.
+ *
+ * Example usage:
+ *
+ * ```cpp
+ * std::map<std::string, std::string> obj =
+ *   simdjson::from(R"({"key": "value"})"_padded);
+ * ```
+ *
+ * This will parse the JSON string and return an object representation. By default, we
+ * use the simdjson::ondemand::parser::get_parser() instance. A parser instance should
+ * be used for just one document at a time.
+ *
+ * You can also pass you own parser instance:
+ * ```cpp
+ * simdjson::ondemand::parser parser;
+ * std::map<std::string, std::string> obj =
+ *   simdjson::from(parser, R"({"key": "value"})"_padded);
+ * ```
+ * The parser instance can be reused.
+ *
+ * This functionality requires C++20 or better.
+ */
+static constexpr convert::internal::to_adaptor<> from{};
+
+} // namespace simdjson
+
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
+#endif // SIMDJSON_CONVERT_H

include/simdjson/dom/array-inl.h

@@ -52,11 +52,22 @@ inline simdjson_result<dom::element> simdjson_result<dom::array>::at_pointer(std
   return at_pointer(json_pointer);
  }
 
+inline simdjson_result<std::vector<dom::element>> simdjson_result<dom::array>::at_path_with_wildcard(std::string_view json_path) const noexcept {
+  if (error()) {
+    return error();
+  }
+  return first.at_path_with_wildcard(json_path);
+}
+
 inline simdjson_result<dom::element> simdjson_result<dom::array>::at(size_t index) const noexcept {
   if (error()) { return error(); }
   return first.at(index);
 }
 
+inline std::vector<dom::element>& simdjson_result<dom::array>::get_values(std::vector<dom::element>& out) const noexcept {
+  return first.get_values(out);
+}
+
 namespace dom {
 
 //
@@ -127,6 +138,93 @@ inline simdjson_result<element> array::at_path(std::string_view json_path) const
   return at_pointer(json_pointer);
 }
 
+inline void array::process_json_path_of_child_elements(std::vector<element>::iterator& current, std::vector<element>::iterator& end, const std::string_view& path_suffix, std::vector<element>& accumulator) const noexcept {
+  if (current == end) {
+    return;
+  }
+
+  simdjson_result<std::vector<element>> result;
+
+
+  for (auto it = current; it != end; ++it) {
+    std::vector<element> child_result;
+    auto error = it->at_path_with_wildcard(path_suffix).get(child_result);
+    if(error) {
+      continue;
+    }
+    accumulator.reserve(accumulator.size() + child_result.size());
+    accumulator.insert(accumulator.end(),
+                        std::make_move_iterator(child_result.begin()),
+                        std::make_move_iterator(child_result.end()));
+  }
+}
+
+inline simdjson_result<std::vector<element>> array::at_path_with_wildcard(std::string_view json_path) const noexcept {
+  SIMDJSON_DEVELOPMENT_ASSERT(tape.usable()); // https://github.com/simdjson/simdjson/issues/1914
+
+  size_t i = 0;
+   // json_path.starts_with('$') requires C++20.
+  if (!json_path.empty() && json_path.front() == '$') {
+    i = 1;
+  }
+
+  if (i >= json_path.size() || (json_path[i] != '.' && json_path[i] != '[')) {
+    return INVALID_JSON_POINTER;
+  }
+
+  if (json_path.find("*") != std::string::npos) {
+    std::vector<element> child_values;
+
+    if (
+      (json_path.compare(i, 3, "[*]") == 0 && json_path.size() == i + 3) ||
+      (json_path.compare(i, 2,".*") == 0 && json_path.size() == i + 2)
+    ) {
+      get_values(child_values);
+      return child_values;
+    }
+
+    std::pair<std::string_view, std::string_view> key_and_json_path = get_next_key_and_json_path(json_path);
+
+    std::string_view key = key_and_json_path.first;
+    json_path = key_and_json_path.second;
+
+    if (key.size() > 0) {
+      if (key == "*") {
+        get_values(child_values);
+      } else {
+        element pointer_result;
+        std::string json_pointer = std::string("/") + std::string(key);
+        auto error = at_pointer(json_pointer).get(pointer_result);
+
+        if (!error) {
+          child_values.emplace_back(pointer_result);
+        }
+      }
+
+      std::vector<element> result = {};
+
+      if (child_values.size() > 0) {
+        std::vector<element>::iterator child_values_begin = child_values.begin();
+        std::vector<element>::iterator child_values_end = child_values.end();
+
+        process_json_path_of_child_elements(child_values_begin, child_values_end, json_path, result);
+      }
+
+      return result;
+    } else {
+      return INVALID_JSON_POINTER;
+    }
+  } else {
+    element result;
+    auto error = at_path(json_path).get(result);
+    if (error) {
+      return error;
+    }
+
+    return std::vector<element>{std::move(result)};
+  }
+}
+
 inline simdjson_result<element> array::at(size_t index) const noexcept {
   SIMDJSON_DEVELOPMENT_ASSERT(tape.usable()); // https://github.com/simdjson/simdjson/issues/1914
   size_t i=0;
@@ -137,6 +235,15 @@ inline simdjson_result<element> array::at(size_t index) const noexcept {
   return INDEX_OUT_OF_BOUNDS;
 }
 
+inline std::vector<element>& array::get_values(std::vector<element>& out) const noexcept {
+  out.reserve(this->size());
+  for (auto element : *this) {
+    out.emplace_back(element);
+  }
+
+  return out;
+}
+
 inline array::operator element() const noexcept {
 	return element(tape);
 }
@@ -183,13 +290,13 @@ inline bool array::iterator::operator>(const array::iterator& other) const noexc
 
 #include "simdjson/dom/element-inl.h"
 
-#if defined(__cpp_lib_ranges)
+#if SIMDJSON_SUPPORTS_RANGES
 static_assert(std::ranges::view<simdjson::dom::array>);
 static_assert(std::ranges::sized_range<simdjson::dom::array>);
 #if SIMDJSON_EXCEPTIONS
 static_assert(std::ranges::view<simdjson::simdjson_result<simdjson::dom::array>>);
 static_assert(std::ranges::sized_range<simdjson::simdjson_result<simdjson::dom::array>>);
 #endif // SIMDJSON_EXCEPTIONS
-#endif // defined(__cpp_lib_ranges)
+#endif // SIMDJSON_SUPPORTS_RANGES
 
 #endif // SIMDJSON_ARRAY_INL_H

include/simdjson/dom/array.h

@@ -1,6 +1,8 @@
 #ifndef SIMDJSON_DOM_ARRAY_H
 #define SIMDJSON_DOM_ARRAY_H
 
+#include <vector>
+
 #include "simdjson/dom/base.h"
 #include "simdjson/internal/tape_ref.h"
 
@@ -57,7 +59,7 @@ public:
     iterator& operator=(const iterator&) noexcept = default;
   private:
     simdjson_inline iterator(const internal::tape_ref &tape) noexcept;
-    internal::tape_ref tape;
+    internal::tape_ref tape{};
     friend class array;
   };
 
@@ -108,6 +110,17 @@ public:
    */
   inline simdjson_result<element> at_pointer(std::string_view json_pointer) const noexcept;
 
+  /**
+   * Recursive function which processes the json path of each child element
+   */
+  inline void process_json_path_of_child_elements(std::vector<element>::iterator& current, std::vector<element>::iterator& end, const std::string_view& path_suffix, std::vector<element>& accumulator) const noexcept;
+
+
+  /**
+   * Adds support for JSONPath expression with wildcards '*'
+   */
+  inline simdjson_result<std::vector<element>> at_path_with_wildcard(std::string_view json_path) const noexcept;
+
   /**
    * Get the value associated with the given JSONPath expression. We only support
    * JSONPath queries that trivially convertible to JSON Pointer queries: key
@@ -141,6 +154,15 @@ public:
    */
   inline simdjson_result<element> at(size_t index) const noexcept;
 
+  /**
+   * Gets the values of items in an array element
+   * This function has linear-time complexity: the values are checked one by one.
+   *
+   * @return The child elements of an array
+   */
+
+  inline std::vector<element>& get_values(std::vector<element>& out) const noexcept;
+
   /**
    * Implicitly convert object to element
    */
@@ -148,7 +170,7 @@ public:
 
 private:
   simdjson_inline array(const internal::tape_ref &tape) noexcept;
-  internal::tape_ref tape;
+  internal::tape_ref tape{};
   friend class element;
   friend struct simdjson_result<element>;
   template<typename T>
@@ -167,8 +189,11 @@ public:
   simdjson_inline simdjson_result(error_code error) noexcept; ///< @private
 
   inline simdjson_result<dom::element> at_pointer(std::string_view json_pointer) const noexcept;
+  inline void process_json_path_of_child_elements(std::vector<dom::element>::iterator& current, std::vector<dom::element>::iterator& end, const std::string_view& path_suffix, std::vector<dom::element>& accumulator) const noexcept;
+  inline simdjson_result<std::vector<dom::element>> at_path_with_wildcard(std::string_view json_path) const noexcept;
   inline simdjson_result<dom::element> at_path(std::string_view json_path) const noexcept;
   inline simdjson_result<dom::element> at(size_t index) const noexcept;
+  inline std::vector<dom::element>& get_values(std::vector<dom::element>& out) const noexcept;
 
 #if SIMDJSON_EXCEPTIONS
   inline dom::array::iterator begin() const noexcept(false);
@@ -181,9 +206,7 @@ public:
 
 } // namespace simdjson
 
-#if defined(__cpp_lib_ranges)
-#include <ranges>
-
+#if SIMDJSON_SUPPORTS_RANGES
 namespace std {
 namespace ranges {
 template<>
@@ -194,6 +217,6 @@ inline constexpr bool enable_view<simdjson::simdjson_result<simdjson::dom::array
 #endif // SIMDJSON_EXCEPTIONS
 } // namespace ranges
 } // namespace std
-#endif // defined(__cpp_lib_ranges)
+#endif // SIMDJSON_SUPPORTS_RANGES
 
 #endif // SIMDJSON_DOM_ARRAY_H

include/simdjson/dom/element-inl.h

@@ -128,6 +128,12 @@ simdjson_inline simdjson_result<dom::element> simdjson_result<dom::element>::at_
   if (json_pointer == "-1") { return INVALID_JSON_POINTER; }
   return at_pointer(json_pointer);
 }
+
+simdjson_inline simdjson_result<std::vector<dom::element>> simdjson_result<dom::element>::at_path_with_wildcard(const std::string_view json_path) const noexcept {
+  if (error()) { return error(); }
+  return first.at_path_with_wildcard(json_path);
+}
+
 #ifndef SIMDJSON_DISABLE_DEPRECATED_API
 [[deprecated("For standard compliance, use at_pointer instead, and prefix your pointers with a slash '/', see RFC6901 ")]]
 simdjson_inline simdjson_result<dom::element> simdjson_result<dom::element>::at(const std::string_view json_pointer) const noexcept {
@@ -418,6 +424,20 @@ inline simdjson_result<element> element::at_pointer(std::string_view json_pointe
     }
   }
 }
+
+inline simdjson_result<std::vector<element>> element::at_path_with_wildcard(std::string_view json_path) const noexcept {
+  SIMDJSON_DEVELOPMENT_ASSERT(tape.usable()); // https://github.com/simdjson/simdjson/issues/1914
+
+  switch (tape.tape_ref_type()) {
+    case internal::tape_type::START_OBJECT:
+      return object(tape).at_path_with_wildcard(json_path);
+    case internal::tape_type::START_ARRAY:
+      return array(tape).at_path_with_wildcard(json_path);
+    default:
+      return std::vector<element>{};
+  }
+}
+
 inline simdjson_result<element> element::at_path(std::string_view json_path) const noexcept {
   auto json_pointer = json_path_to_pointer_conversion(json_path);
   if (json_pointer == "-1") { return INVALID_JSON_POINTER; }

include/simdjson/dom/element.h

@@ -1,6 +1,8 @@
 #ifndef SIMDJSON_DOM_ELEMENT_H
 #define SIMDJSON_DOM_ELEMENT_H
 
+#include <vector>
+
 #include "simdjson/dom/base.h"
 #include "simdjson/dom/array.h"
 
@@ -399,6 +401,8 @@ public:
    */
   inline simdjson_result<element> at_pointer(const std::string_view json_pointer) const noexcept;
 
+  inline simdjson_result<std::vector<element>> at_path_with_wildcard(const std::string_view json_path) const noexcept;
+
   /**
    * Get the value associated with the given JSONPath expression. We only support
    * JSONPath queries that trivially convertible to JSON Pointer queries: key
@@ -492,7 +496,7 @@ public:
 
 private:
   simdjson_inline element(const internal::tape_ref &tape) noexcept;
-  internal::tape_ref tape;
+  internal::tape_ref tape{};
   friend class document;
   friend class object;
   friend class array;
@@ -544,6 +548,7 @@ public:
   simdjson_inline simdjson_result<dom::element> operator[](const char *key) const noexcept;
   simdjson_result<dom::element> operator[](int) const noexcept = delete;
   simdjson_inline simdjson_result<dom::element> at_pointer(const std::string_view json_pointer) const noexcept;
+  simdjson_inline simdjson_result<std::vector<dom::element>> at_path_with_wildcard(const std::string_view json_path) const noexcept;
   simdjson_inline simdjson_result<dom::element> at_path(const std::string_view json_path) const noexcept;
   [[deprecated("For standard compliance, use at_pointer instead, and prefix your pointers with a slash '/', see RFC6901 ")]]
   simdjson_inline simdjson_result<dom::element> at(const std::string_view json_pointer) const noexcept;

include/simdjson/dom/object-inl.h

@@ -40,10 +40,19 @@ inline simdjson_result<dom::element> simdjson_result<dom::object>::at_path(std::
   if (json_pointer == "-1") { return INVALID_JSON_POINTER; }
   return at_pointer(json_pointer);
 }
+inline simdjson_result<std::vector<dom::element>> simdjson_result<dom::object>::at_path_with_wildcard(std::string_view json_path) const noexcept {
+  if (error()) {
+    return error();
+  }
+  return first.at_path_with_wildcard(json_path);
+}
 inline simdjson_result<dom::element> simdjson_result<dom::object>::at_key(std::string_view key) const noexcept {
   if (error()) { return error(); }
   return first.at_key(key);
 }
+inline std::vector<dom::element>& simdjson_result<dom::object>::get_values(std::vector<dom::element>& out) const noexcept {
+  return first.get_values(out);
+}
 inline simdjson_result<dom::element> simdjson_result<dom::object>::at_key_case_insensitive(std::string_view key) const noexcept {
   if (error()) { return error(); }
   return first.at_key_case_insensitive(key);
@@ -143,6 +152,97 @@ inline simdjson_result<element> object::at_path(std::string_view json_path) cons
   return at_pointer(json_pointer);
 }
 
+inline void object::process_json_path_of_child_elements(std::vector<element>::iterator& current, std::vector<element>::iterator& end, const std::string_view& path_suffix, std::vector<element>& accumulator) const noexcept {
+  if (current == end) {
+    return;
+  }
+
+  simdjson_result<std::vector<element>> result;
+
+  for (auto it = current; it != end; ++it) {
+    std::vector<element> child_result;
+    auto error = it->at_path_with_wildcard(path_suffix).get(child_result);
+    if(error) {
+      continue;
+    }
+    accumulator.reserve(accumulator.size() + child_result.size());
+    accumulator.insert(accumulator.end(),
+                        std::make_move_iterator(child_result.begin()),
+                        std::make_move_iterator(child_result.end()));
+  }
+}
+
+inline simdjson_result<std::vector<element>> object::at_path_with_wildcard(std::string_view json_path) const noexcept {
+  SIMDJSON_DEVELOPMENT_ASSERT(tape.usable()); // https://github.com/simdjson/simdjson/issues/1914
+
+  size_t i = 0;
+  if (json_path.empty()) {
+    return INVALID_JSON_POINTER;
+  }
+  // if JSONPath starts with $, skip it
+  // json_path.starts_with('$') requires C++20.
+  if (json_path.front() == '$') {
+    i = 1;
+  }
+
+  if (i >= json_path.size() || (json_path[i] != '.' && json_path[i] != '[')) {
+    // expect json path to always start with $ but this isn't currently
+    // expected in jsonpathutil.h.
+    return INVALID_JSON_POINTER;
+  }
+
+  if (json_path.find("*") != std::string::npos) {
+
+    std::vector<element> child_values;
+
+    if (
+      (json_path.compare(i, 3, "[*]") == 0 && json_path.size() == i + 3) ||
+      (json_path.compare(i, 2,".*") == 0 && json_path.size() == i + 2)
+    ) {
+      get_values(child_values);
+      return child_values;
+    }
+
+    std::pair<std::string_view, std::string_view> key_and_json_path = get_next_key_and_json_path(json_path);
+
+    std::string_view key = key_and_json_path.first;
+    json_path = key_and_json_path.second;
+
+    if (key.size() > 0) {
+      if (key == "*") {
+        get_values(child_values);
+      } else {
+        element pointer_result;
+        auto error = at_pointer(std::string("/") + std::string(key)).get(pointer_result);
+
+        if (!error) {
+          child_values.emplace_back(pointer_result);
+        }
+      }
+
+      std::vector<element> result = {};
+      if (child_values.size() > 0) {
+
+        std::vector<element>::iterator child_values_begin = child_values.begin();
+        std::vector<element>::iterator child_values_end = child_values.end();
+
+        process_json_path_of_child_elements(child_values_begin, child_values_end, json_path, result);
+      }
+
+      return result;
+    } else {
+      return INVALID_JSON_POINTER;
+    }
+  } else {
+    element result;
+    auto error = this->at_path(json_path).get(result);
+    if (error) {
+      return error;
+    }
+    return std::vector<element>{std::move(result)};
+  }
+}
+
 inline simdjson_result<element> object::at_key(std::string_view key) const noexcept {
   iterator end_field = end();
   for (iterator field = begin(); field != end_field; ++field) {
@@ -152,6 +252,18 @@ inline simdjson_result<element> object::at_key(std::string_view key) const noexc
   }
   return NO_SUCH_FIELD;
 }
+
+inline std::vector<element>& object::get_values(std::vector<element>& out) const noexcept {
+  iterator end_field = end();
+  iterator begin_field = begin();
+
+  out.reserve(std::distance(begin_field, end_field));
+  for (iterator field = begin_field; field != end_field; ++field) {
+    out.emplace_back(field.value());
+  }
+
+  return out;
+}
 // In case you wonder why we need this, please see
 // https://github.com/simdjson/simdjson/issues/323
 // People do seek keys in a case-insensitive manner.
@@ -263,13 +375,13 @@ inline key_value_pair::key_value_pair(std::string_view _key, element _value) noe
 
 } // namespace simdjson
 
-#if defined(__cpp_lib_ranges)
+#if SIMDJSON_SUPPORTS_RANGES
 static_assert(std::ranges::view<simdjson::dom::object>);
 static_assert(std::ranges::sized_range<simdjson::dom::object>);
 #if SIMDJSON_EXCEPTIONS
 static_assert(std::ranges::view<simdjson::simdjson_result<simdjson::dom::object>>);
 static_assert(std::ranges::sized_range<simdjson::simdjson_result<simdjson::dom::object>>);
 #endif // SIMDJSON_EXCEPTIONS
-#endif // defined(__cpp_lib_ranges)
+#endif // SIMDJSON_SUPPORTS_RANGES
 
 #endif // SIMDJSON_OBJECT_INL_H

include/simdjson/dom/object.h

@@ -1,6 +1,8 @@
 #ifndef SIMDJSON_DOM_OBJECT_H
 #define SIMDJSON_DOM_OBJECT_H
 
+#include <vector>
+
 #include "simdjson/dom/base.h"
 #include "simdjson/dom/element.h"
 #include "simdjson/internal/tape_ref.h"
@@ -89,7 +91,7 @@ public:
   private:
     simdjson_inline iterator(const internal::tape_ref &tape) noexcept;
 
-    internal::tape_ref tape;
+    internal::tape_ref tape{};
 
     friend class object;
   };
@@ -172,6 +174,16 @@ public:
    */
   inline simdjson_result<element> at_pointer(std::string_view json_pointer) const noexcept;
 
+  /**
+   * Recursive function which processes the json path of each child element
+   */
+  inline void process_json_path_of_child_elements(std::vector<element>::iterator& current, std::vector<element>::iterator& end, const std::string_view& path_suffix, std::vector<element>& accumulator) const noexcept;
+
+  /**
+   * Adds support for JSONPath expression with wildcards '*'
+   */
+  inline simdjson_result<std::vector<element>> at_path_with_wildcard(std::string_view json_path) const noexcept;
+
   /**
    * Get the value associated with the given JSONPath expression. We only support
    * JSONPath queries that trivially convertible to JSON Pointer queries: key
@@ -203,6 +215,14 @@ public:
    */
   inline simdjson_result<element> at_key(std::string_view key) const noexcept;
 
+  /**
+   * Gets the values associated with keys of an object
+   * This function has linear-time complexity: the keys are checked one by one.
+   *
+   * @return the values associated with each key of an object
+   */
+  inline std::vector<element>& get_values(std::vector<element>& out) const noexcept;
+
   /**
    * Get the value associated with the given key in a case-insensitive manner.
    * It is only guaranteed to work over ASCII inputs.
@@ -224,7 +244,7 @@ public:
 private:
   simdjson_inline object(const internal::tape_ref &tape) noexcept;
 
-  internal::tape_ref tape;
+  internal::tape_ref tape{};
 
   friend class element;
   friend struct simdjson_result<element>;
@@ -261,8 +281,11 @@ public:
   inline simdjson_result<dom::element> operator[](const char *key) const noexcept;
   simdjson_result<dom::element> operator[](int) const noexcept = delete;
   inline simdjson_result<dom::element> at_pointer(std::string_view json_pointer) const noexcept;
+  inline void process_json_path_of_child_elements(std::vector<dom::element>::iterator& current, std::vector<dom::element>::iterator& end, const std::string_view& path_suffix, std::vector<dom::element>& accumulator) const noexcept;
+  inline simdjson_result<std::vector<dom::element>> at_path_with_wildcard(std::string_view json_path_new) const noexcept;
   inline simdjson_result<dom::element> at_path(std::string_view json_path) const noexcept;
   inline simdjson_result<dom::element> at_key(std::string_view key) const noexcept;
+  inline std::vector<dom::element>& get_values(std::vector<dom::element>& out) const noexcept;
   inline simdjson_result<dom::element> at_key_case_insensitive(std::string_view key) const noexcept;
 
 #if SIMDJSON_EXCEPTIONS
@@ -274,9 +297,7 @@ public:
 
 } // namespace simdjson
 
-#if defined(__cpp_lib_ranges)
-#include <ranges>
-
+#if SIMDJSON_SUPPORTS_RANGES
 namespace std {
 namespace ranges {
 template<>
@@ -287,6 +308,6 @@ inline constexpr bool enable_view<simdjson::simdjson_result<simdjson::dom::objec
 #endif // SIMDJSON_EXCEPTIONS
 } // namespace ranges
 } // namespace std
-#endif // defined(__cpp_lib_ranges)
+#endif // SIMDJSON_SUPPORTS_RANGES
 
 #endif // SIMDJSON_DOM_OBJECT_H

include/simdjson/dom/parser-inl.h

@@ -35,11 +35,11 @@ inline bool parser::dump_raw_tape(std::ostream &os) const noexcept {
   return valid ? doc.dump_raw_tape(os) : false;
 }
 
-inline simdjson_result<size_t> parser::read_file(const std::string &path) noexcept {
+inline simdjson_result<size_t> parser::read_file(std::string_view path) noexcept {
   // Open the file
   SIMDJSON_PUSH_DISABLE_WARNINGS
   SIMDJSON_DISABLE_DEPRECATED_WARNING // Disable CRT_SECURE warning on MSVC: manually verified this is safe
-  std::FILE *fp = std::fopen(path.c_str(), "rb");
+  std::FILE *fp = std::fopen(path.data(), "rb");
   SIMDJSON_POP_DISABLE_WARNINGS
 
   if (fp == nullptr) {
@@ -91,18 +91,18 @@ inline simdjson_result<size_t> parser::read_file(const std::string &path) noexce
   return bytes_read;
 }
 
-inline simdjson_result<element> parser::load(const std::string &path) & noexcept {
+inline simdjson_result<element> parser::load(std::string_view path) & noexcept {
   return load_into_document(doc, path);
 }
 
-inline simdjson_result<element> parser::load_into_document(document& provided_doc, const std::string &path) & noexcept {
+inline simdjson_result<element> parser::load_into_document(document& provided_doc, std::string_view path) & noexcept {
   size_t len;
   auto _error = read_file(path).get(len);
   if (_error) { return _error; }
   return parse_into_document(provided_doc, loaded_bytes.get(), len, false);
 }
 
-inline simdjson_result<document_stream> parser::load_many(const std::string &path, size_t batch_size) noexcept {
+inline simdjson_result<document_stream> parser::load_many(std::string_view path, size_t batch_size) noexcept {
   size_t len;
   auto _error = read_file(path).get(len);
   if (_error) { return _error; }

include/simdjson/dom/parser.h

@@ -102,8 +102,8 @@ public:
    *         - other json errors if parsing fails. You should not rely on these errors to always the same for the
    *           same document: they may vary under runtime dispatch (so they may vary depending on your system and hardware).
    */
-  inline simdjson_result<element> load(const std::string &path) & noexcept;
-  inline simdjson_result<element> load(const std::string &path) &&  = delete ;
+  inline simdjson_result<element> load(std::string_view path) & noexcept;
+  inline simdjson_result<element> load(std::string_view path) &&  = delete ;
 
   /**
    * Load a JSON document from a file into a provide document instance and return a temporary reference to it.
@@ -148,8 +148,8 @@ public:
    *         - other json errors if parsing fails. You should not rely on these errors to always the same for the
    *           same document: they may vary under runtime dispatch (so they may vary depending on your system and hardware).
    */
-  inline simdjson_result<element> load_into_document(document& doc, const std::string &path) & noexcept;
-  inline simdjson_result<element> load_into_document(document& doc, const std::string &path) && =delete;
+  inline simdjson_result<element> load_into_document(document& doc, std::string_view path) & noexcept;
+  inline simdjson_result<element> load_into_document(document& doc, std::string_view path) && =delete;
 
   /**
    * Parse a JSON document and return a temporary reference to it.
@@ -386,7 +386,7 @@ public:
    *         - other json errors if parsing fails. You should not rely on these errors to always the same for the
    *           same document: they may vary under runtime dispatch (so they may vary depending on your system and hardware).
    */
-  inline simdjson_result<document_stream> load_many(const std::string &path, size_t batch_size = dom::DEFAULT_BATCH_SIZE) noexcept;
+  inline simdjson_result<document_stream> load_many(std::string_view path, size_t batch_size = dom::DEFAULT_BATCH_SIZE) noexcept;
 
   /**
    * Parse a buffer containing many JSON documents.
@@ -657,7 +657,7 @@ private:
   inline error_code ensure_capacity(document& doc, size_t desired_capacity) noexcept;
 
   /** Read the file into loaded_bytes */
-  inline simdjson_result<size_t> read_file(const std::string &path) noexcept;
+  inline simdjson_result<size_t> read_file(std::string_view path) noexcept;
 
   friend class parser::Iterator;
   friend class document_stream;

include/simdjson/dom/serialization-inl.h

@@ -3,8 +3,8 @@
 #define SIMDJSON_SERIALIZATION_INL_H
 
 #include "simdjson/dom/base.h"
-#include "simdjson/dom/serialization.h"
 #include "simdjson/dom/parser.h"
+#include "simdjson/dom/serialization.h"
 #include "simdjson/internal/tape_type.h"
 
 #include "simdjson/dom/array-inl.h"
@@ -16,7 +16,9 @@
 namespace simdjson {
 namespace dom {
 inline bool parser::print_json(std::ostream &os) const noexcept {
-  if (!valid) { return false; }
+  if (!valid) {
+    return false;
+  }
   simdjson::internal::string_builder<> sb;
   sb.append(doc.root());
   std::string_view answer = sb.str();
@@ -24,37 +26,51 @@ inline bool parser::print_json(std::ostream &os) const noexcept {
   return true;
 }
 
-inline std::ostream& operator<<(std::ostream& out, simdjson::dom::element value) {
-    simdjson::internal::string_builder<> sb;
-    sb.append(value);
-    return (out << sb.str());
+inline std::ostream &operator<<(std::ostream &out,
+                                simdjson::dom::element value) {
+  simdjson::internal::string_builder<> sb;
+  sb.append(value);
+  return (out << sb.str());
 }
 #if SIMDJSON_EXCEPTIONS
-inline std::ostream& operator<<(std::ostream& out, simdjson::simdjson_result<simdjson::dom::element> x) {
-    if (x.error()) { throw simdjson::simdjson_error(x.error()); }
-    return (out << x.value());
+inline std::ostream &
+operator<<(std::ostream &out,
+           simdjson::simdjson_result<simdjson::dom::element> x) {
+  if (x.error()) {
+    throw simdjson::simdjson_error(x.error());
+  }
+  return (out << x.value());
 }
 #endif
-inline std::ostream& operator<<(std::ostream& out, simdjson::dom::array value)  {
-    simdjson::internal::string_builder<> sb;
-    sb.append(value);
-    return (out << sb.str());
+inline std::ostream &operator<<(std::ostream &out, simdjson::dom::array value) {
+  simdjson::internal::string_builder<> sb;
+  sb.append(value);
+  return (out << sb.str());
 }
 #if SIMDJSON_EXCEPTIONS
-inline std::ostream& operator<<(std::ostream& out, simdjson::simdjson_result<simdjson::dom::array> x) {
-    if (x.error()) { throw simdjson::simdjson_error(x.error()); }
-    return (out << x.value());
+inline std::ostream &
+operator<<(std::ostream &out,
+           simdjson::simdjson_result<simdjson::dom::array> x) {
+  if (x.error()) {
+    throw simdjson::simdjson_error(x.error());
+  }
+  return (out << x.value());
 }
 #endif
-inline std::ostream& operator<<(std::ostream& out, simdjson::dom::object value)   {
-    simdjson::internal::string_builder<> sb;
-    sb.append(value);
-    return (out << sb.str());
+inline std::ostream &operator<<(std::ostream &out,
+                                simdjson::dom::object value) {
+  simdjson::internal::string_builder<> sb;
+  sb.append(value);
+  return (out << sb.str());
 }
 #if SIMDJSON_EXCEPTIONS
-inline std::ostream& operator<<(std::ostream& out,  simdjson::simdjson_result<simdjson::dom::object> x) {
-    if (x.error()) { throw  simdjson::simdjson_error(x.error()); }
-    return (out << x.value());
+inline std::ostream &
+operator<<(std::ostream &out,
+           simdjson::simdjson_result<simdjson::dom::object> x) {
+  if (x.error()) {
+    throw simdjson::simdjson_error(x.error());
+  }
+  return (out << x.value());
 }
 #endif
 
@@ -69,8 +85,9 @@ namespace {
  * We expect that most compilers will use 8 bytes for this data structure.
  **/
 struct escape_sequence {
-    uint8_t length;
-    const char string[7]; // technically, we only ever need 6 characters, we pad to 8
+  uint8_t length;
+  const char
+      string[7]; // technically, we only ever need 6 characters, we pad to 8
 };
 /**@private
  * This converts a signed integer into a character sequence.
@@ -86,7 +103,7 @@ static char *fast_itoa(char *output, int64_t value) noexcept {
   char buffer[20];
   uint64_t value_positive;
   // In general, negating a signed integer is unsafe.
-  if(value < 0) {
+  if (value < 0) {
     *output++ = '-';
     // Doing value_positive = -value; while avoiding
     // undefined behavior warnings.
@@ -105,7 +122,7 @@ static char *fast_itoa(char *output, int64_t value) noexcept {
   // A faster approach is possible if we expect large integers:
   // unroll the loop (work in 100s, 1000s) and use some kind of
   // memoization.
-  while(value_positive >= 10) {
+  while (value_positive >= 10) {
     *write_pointer-- = char('0' + (value_positive % 10));
     value_positive /= 10;
   }
@@ -131,7 +148,7 @@ static char *fast_itoa(char *output, uint64_t value) noexcept {
   // A faster approach is possible if we expect large integers:
   // unroll the loop (work in 100s, 1000s) and use some kind of
   // memoization.
-  while(value >= 10) {
+  while (value >= 10) {
     *write_pointer-- = char('0' + (value % 10));
     value /= 10;
   };
@@ -141,7 +158,6 @@ static char *fast_itoa(char *output, uint64_t value) noexcept {
   return output + len;
 }
 
-
 } // anonymous namespace
 namespace internal {
 
@@ -149,193 +165,208 @@ namespace internal {
  * Minifier/formatter code.
  **/
 
-template<class formatter>
+template <class formatter>
 simdjson_inline void base_formatter<formatter>::number(uint64_t x) {
   char number_buffer[24];
   char *newp = fast_itoa(number_buffer, x);
-  buffer.insert(buffer.end(), number_buffer, newp);
+  chars(number_buffer, newp);
 }
 
-template<class formatter>
+template <class formatter>
 simdjson_inline void base_formatter<formatter>::number(int64_t x) {
   char number_buffer[24];
   char *newp = fast_itoa(number_buffer, x);
-  buffer.insert(buffer.end(), number_buffer, newp);
+  chars(number_buffer, newp);
 }
 
-template<class formatter>
+template <class formatter>
 simdjson_inline void base_formatter<formatter>::number(double x) {
   char number_buffer[24];
   // Currently, passing the nullptr to the second argument is
   // safe because our implementation does not check the second
   // argument.
   char *newp = internal::to_chars(number_buffer, nullptr, x);
-  buffer.insert(buffer.end(), number_buffer, newp);
+  chars(number_buffer, newp);
 }
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::start_array() { one_char('['); }
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::start_array() {
+  one_char('[');
+}
 
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::end_array() {
+  one_char(']');
+}
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::end_array() { one_char(']'); }
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::start_object() {
+  one_char('{');
+}
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::start_object() { one_char('{'); }
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::end_object() {
+  one_char('}');
+}
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::end_object() { one_char('}'); }
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::comma() {
+  one_char(',');
+}
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::comma() { one_char(','); }
-
-template<class formatter>
+template <class formatter>
 simdjson_inline void base_formatter<formatter>::true_atom() {
-  const char * s = "true";
-  buffer.insert(buffer.end(), s, s + 4);
+  const char *s = "true";
+  chars(s, s + 4);
 }
 
-template<class formatter>
+template <class formatter>
 simdjson_inline void base_formatter<formatter>::false_atom() {
-  const char * s = "false";
-  buffer.insert(buffer.end(), s, s + 5);
+  const char *s = "false";
+  chars(s, s + 5);
 }
 
-template<class formatter>
+template <class formatter>
 simdjson_inline void base_formatter<formatter>::null_atom() {
-  const char * s = "null";
-  buffer.insert(buffer.end(), s, s + 4);
+  const char *s = "null";
+  chars(s, s + 4);
 }
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::one_char(char c) { buffer.push_back(c); }
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::one_char(char c) {
+  buffer.push_back(c);
+}
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::key(std::string_view unescaped) {
+template <class formatter>
+simdjson_inline void base_formatter<formatter>::chars(const char *begin,
+                                                      const char *end) {
+  buffer.append(begin, end);
+}
+
+template <class formatter>
+simdjson_inline void
+base_formatter<formatter>::key(std::string_view unescaped) {
   string(unescaped);
   one_char(':');
 }
 
-template<class formatter>
-simdjson_inline void base_formatter<formatter>::string(std::string_view unescaped) {
+template <class formatter>
+simdjson_inline void
+base_formatter<formatter>::string(std::string_view unescaped) {
   one_char('\"');
   size_t i = 0;
-  // Fast path for the case where we have no control character, no ", and no backslash.
-  // This should include most keys.
+  // Fast path for the case where we have no control character, no ", and no
+  // backslash. This should include most keys.
   //
-  // We would like to use 'bool' but some compilers take offense to bitwise operation
-  // with bool types.
-  constexpr static char needs_escaping[] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
-  for(;i + 8 <= unescaped.length(); i += 8) {
+  // We would like to use 'bool' but some compilers take offense to bitwise
+  // operation with bool types.
+  constexpr static char needs_escaping[] = {
+      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+      1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  for (; i + 8 <= unescaped.length(); i += 8) {
     // Poor's man vectorization. This could get much faster if we used SIMD.
     //
-    // It is not the case that replacing '|' with '||' would be neutral performance-wise.
-    if(needs_escaping[uint8_t(unescaped[i])] | needs_escaping[uint8_t(unescaped[i+1])]
-      | needs_escaping[uint8_t(unescaped[i+2])] | needs_escaping[uint8_t(unescaped[i+3])]
-      | needs_escaping[uint8_t(unescaped[i+4])] | needs_escaping[uint8_t(unescaped[i+5])]
-      | needs_escaping[uint8_t(unescaped[i+6])] | needs_escaping[uint8_t(unescaped[i+7])]
-      ) { break; }
+    // It is not the case that replacing '|' with '||' would be neutral
+    // performance-wise.
+    if (needs_escaping[uint8_t(unescaped[i])] |
+        needs_escaping[uint8_t(unescaped[i + 1])] |
+        needs_escaping[uint8_t(unescaped[i + 2])] |
+        needs_escaping[uint8_t(unescaped[i + 3])] |
+        needs_escaping[uint8_t(unescaped[i + 4])] |
+        needs_escaping[uint8_t(unescaped[i + 5])] |
+        needs_escaping[uint8_t(unescaped[i + 6])] |
+        needs_escaping[uint8_t(unescaped[i + 7])]) {
+      break;
+    }
   }
-  for(;i < unescaped.length(); i++) {
-    if(needs_escaping[uint8_t(unescaped[i])]) { break; }
+  for (; i < unescaped.length(); i++) {
+    if (needs_escaping[uint8_t(unescaped[i])]) {
+      break;
+    }
   }
-  // The following is also possible and omits a 256-byte table, but it is slower:
-  // for (; (i < unescaped.length()) && (uint8_t(unescaped[i]) > 0x1F)
+  // The following is also possible and omits a 256-byte table, but it is
+  // slower: for (; (i < unescaped.length()) && (uint8_t(unescaped[i]) > 0x1F)
   //      && (unescaped[i] != '\"') && (unescaped[i] != '\\'); i++) {}
 
   // At least for long strings, the following should be fast. We could
   // do better by integrating the checks and the insertion.
-  buffer.insert(buffer.end(), unescaped.data(), unescaped.data() + i);
+  chars(unescaped.data(), unescaped.data() + i);
   // We caught a control character if we enter this loop (slow).
   // Note that we are do not restart from the beginning, but rather we continue
   // from the point where we encountered something that requires escaping.
   for (; i < unescaped.length(); i++) {
     switch (unescaped[i]) {
-    case '\"':
-      {
-        const char * s = "\\\"";
-        buffer.insert(buffer.end(), s, s + 2);
-      }
-      break;
-    case '\\':
-      {
-        const char * s = "\\\\";
-        buffer.insert(buffer.end(), s, s + 2);
-      }
-      break;
+    case '\"': {
+      const char *s = "\\\"";
+      chars(s, s + 2);
+    } break;
+    case '\\': {
+      const char *s = "\\\\";
+      chars(s, s + 2);
+    } break;
     default:
       if (uint8_t(unescaped[i]) <= 0x1F) {
         // If packed, this uses 8 * 32 bytes.
         // Note that we expect most compilers to embed this code in the data
         // section.
         constexpr static escape_sequence escaped[32] = {
-          {6, "\\u0000"}, {6, "\\u0001"}, {6, "\\u0002"}, {6, "\\u0003"},
-          {6, "\\u0004"}, {6, "\\u0005"}, {6, "\\u0006"}, {6, "\\u0007"},
-          {2, "\\b"},     {2, "\\t"},     {2, "\\n"},     {6, "\\u000b"},
-          {2, "\\f"},     {2, "\\r"},     {6, "\\u000e"}, {6, "\\u000f"},
-          {6, "\\u0010"}, {6, "\\u0011"}, {6, "\\u0012"}, {6, "\\u0013"},
-          {6, "\\u0014"}, {6, "\\u0015"}, {6, "\\u0016"}, {6, "\\u0017"},
-          {6, "\\u0018"}, {6, "\\u0019"}, {6, "\\u001a"}, {6, "\\u001b"},
-          {6, "\\u001c"}, {6, "\\u001d"}, {6, "\\u001e"}, {6, "\\u001f"}};
+            {6, "\\u0000"}, {6, "\\u0001"}, {6, "\\u0002"}, {6, "\\u0003"},
+            {6, "\\u0004"}, {6, "\\u0005"}, {6, "\\u0006"}, {6, "\\u0007"},
+            {2, "\\b"},     {2, "\\t"},     {2, "\\n"},     {6, "\\u000b"},
+            {2, "\\f"},     {2, "\\r"},     {6, "\\u000e"}, {6, "\\u000f"},
+            {6, "\\u0010"}, {6, "\\u0011"}, {6, "\\u0012"}, {6, "\\u0013"},
+            {6, "\\u0014"}, {6, "\\u0015"}, {6, "\\u0016"}, {6, "\\u0017"},
+            {6, "\\u0018"}, {6, "\\u0019"}, {6, "\\u001a"}, {6, "\\u001b"},
+            {6, "\\u001c"}, {6, "\\u001d"}, {6, "\\u001e"}, {6, "\\u001f"}};
         auto u = escaped[uint8_t(unescaped[i])];
-        buffer.insert(buffer.end(), u.string, u.string + u.length);
+        chars(u.string, u.string + u.length);
       } else {
         one_char(unescaped[i]);
       }
     } // switch
-  }   // for
+  } // for
   one_char('\"');
 }
 
-
-template<class formatter>
-inline void base_formatter<formatter>::clear() {
+template <class formatter> inline void base_formatter<formatter>::clear() {
   buffer.clear();
 }
 
-template<class formatter>
+template <class formatter>
 simdjson_inline std::string_view base_formatter<formatter>::str() const {
-  return std::string_view(buffer.data(), buffer.size());
+  return buffer.str();
 }
 
-simdjson_inline void mini_formatter::print_newline() {
-    return;
-}
+simdjson_inline void mini_formatter::print_newline() { return; }
 
 simdjson_inline void mini_formatter::print_indents(size_t depth) {
-    (void)depth;
-    return;
+  (void)depth;
+  return;
 }
 
-simdjson_inline void mini_formatter::print_space() {
-    return;
-}
+simdjson_inline void mini_formatter::print_space() { return; }
 
-simdjson_inline void pretty_formatter::print_newline() {
-    one_char('\n');
-}
+simdjson_inline void pretty_formatter::print_newline() { one_char('\n'); }
 
 simdjson_inline void pretty_formatter::print_indents(size_t depth) {
-    if(this->indent_step <= 0) {
-        return;
-    }
-    for(size_t i = 0; i < this->indent_step * depth; i++) {
-        one_char(' ');
-    }
+  if (this->indent_step <= 0) {
+    return;
+  }
+  for (size_t i = 0; i < this->indent_step * depth; i++) {
+    one_char(' ');
+  }
 }
 
-simdjson_inline void pretty_formatter::print_space() {
-    one_char(' ');
-}
+simdjson_inline void pretty_formatter::print_space() { one_char(' '); }
 
 /***
  * String building code.
@@ -514,7 +545,8 @@ inline void string_builder<serializer>::append(simdjson::dom::array value) {
 }
 
 template <class serializer>
-simdjson_inline void string_builder<serializer>::append(simdjson::dom::key_value_pair kv) {
+simdjson_inline void
+string_builder<serializer>::append(simdjson::dom::key_value_pair kv) {
   format.key(kv.key);
   append(kv.value);
 }
@@ -529,7 +561,6 @@ simdjson_inline std::string_view string_builder<serializer>::str() const {
   return format.str();
 }
 
-
 } // namespace internal
 } // namespace simdjson
 

include/simdjson/dom/serialization.h

@@ -5,8 +5,6 @@
 #include "simdjson/dom/element.h"
 #include "simdjson/dom/object.h"
 
-#include <vector>
-
 namespace simdjson {
 
 /**
@@ -16,8 +14,7 @@ namespace simdjson {
  */
 namespace internal {
 
-template<class formatter>
-class base_formatter {
+template <class formatter> class base_formatter {
 public:
   /** Add a comma **/
   simdjson_inline void comma();
@@ -56,24 +53,76 @@ public:
   /** Prints one character **/
   simdjson_inline void one_char(char c);
 
+  /** Prints characters in [begin, end) verbatim. **/
+  simdjson_inline void chars(const char *begin, const char *end);
+
   simdjson_inline void call_print_newline() {
-      static_cast<formatter*>(this)->print_newline();
+    static_cast<formatter *>(this)->print_newline();
   }
 
   simdjson_inline void call_print_indents(size_t depth) {
-      static_cast<formatter*>(this)->print_indents(depth);
+    static_cast<formatter *>(this)->print_indents(depth);
   }
 
   simdjson_inline void call_print_space() {
-      static_cast<formatter*>(this)->print_space();
+    static_cast<formatter *>(this)->print_space();
   }
 
 protected:
   // implementation details (subject to change)
   /** Backing buffer **/
-  std::vector<char> buffer{}; // not ideal!
-};
+  struct vector_with_small_buffer {
+    vector_with_small_buffer() = default;
+    ~vector_with_small_buffer() { free_buffer(); }
 
+    vector_with_small_buffer(const vector_with_small_buffer &) = delete;
+    vector_with_small_buffer &
+    operator=(const vector_with_small_buffer &) = delete;
+
+    void clear() {
+      size = 0;
+      capacity = StaticCapacity;
+      free_buffer();
+      buffer = array;
+    }
+
+    simdjson_inline void push_back(char c) {
+      if (capacity < size + 1)
+        grow(capacity * 2);
+      buffer[size++] = c;
+    }
+
+    simdjson_inline void append(const char *begin, const char *end) {
+      const size_t new_size = size + (end - begin);
+      if (capacity < new_size)
+        // std::max(new_size, capacity * 2); is broken in tests on Windows
+        grow(new_size < capacity * 2 ? capacity * 2 : new_size);
+      std::copy(begin, end, buffer + size);
+      size = new_size;
+    }
+
+    std::string_view str() const { return std::string_view(buffer, size); }
+
+  private:
+    void free_buffer() {
+      if (buffer != array)
+        delete[] buffer;
+    }
+    void grow(size_t new_capacity) {
+      auto new_buffer = new char[new_capacity];
+      std::copy(buffer, buffer + size, new_buffer);
+      free_buffer();
+      buffer = new_buffer;
+      capacity = new_capacity;
+    }
+
+    static const size_t StaticCapacity = 64;
+    char array[StaticCapacity];
+    char *buffer = array;
+    size_t size = 0;
+    size_t capacity = StaticCapacity;
+  } buffer{};
+};
 
 /**
  * @private This is the class that we expect to use with the string_builder
@@ -107,9 +156,11 @@ protected:
  * by a "formatter" which handles the details. Thus
  * the string_builder template could support both minification
  * and prettification, and various other tradeoffs.
+ *
+ * This is not to be confused with the simdjson::builder::string_builder
+ * which is a different class.
  */
-template <class formatter = mini_formatter>
-class string_builder {
+template <class formatter = mini_formatter> class string_builder {
 public:
   /** Construct an initially empty builder, would print the empty string **/
   string_builder() = default;
@@ -131,11 +182,12 @@ public:
   simdjson_inline std::string_view str() const;
   /** Append a key_value_pair to the builder (to be printed) **/
   simdjson_inline void append(simdjson::dom::key_value_pair value);
+
 private:
   formatter format{};
 };
 
-} // internal
+} // namespace internal
 
 namespace dom {
 
@@ -144,33 +196,43 @@ namespace dom {
  *
  * @param out The output stream.
  * @param value The element.
- * @throw if there is an error with the underlying output stream. simdjson itself will not throw.
+ * @throw if there is an error with the underlying output stream. simdjson
+ * itself will not throw.
  */
-inline std::ostream& operator<<(std::ostream& out, simdjson::dom::element value);
+inline std::ostream &operator<<(std::ostream &out,
+                                simdjson::dom::element value);
 #if SIMDJSON_EXCEPTIONS
-inline std::ostream& operator<<(std::ostream& out, simdjson::simdjson_result<simdjson::dom::element> x);
+inline std::ostream &
+operator<<(std::ostream &out,
+           simdjson::simdjson_result<simdjson::dom::element> x);
 #endif
 /**
  * Print JSON to an output stream.
  *
  * @param out The output stream.
  * @param value The array.
- * @throw if there is an error with the underlying output stream. simdjson itself will not throw.
+ * @throw if there is an error with the underlying output stream. simdjson
+ * itself will not throw.
  */
-inline std::ostream& operator<<(std::ostream& out, simdjson::dom::array value);
+inline std::ostream &operator<<(std::ostream &out, simdjson::dom::array value);
 #if SIMDJSON_EXCEPTIONS
-inline std::ostream& operator<<(std::ostream& out, simdjson::simdjson_result<simdjson::dom::array> x);
+inline std::ostream &
+operator<<(std::ostream &out,
+           simdjson::simdjson_result<simdjson::dom::array> x);
 #endif
 /**
  * Print JSON to an output stream.
  *
  * @param out The output stream.
  * @param value The object.
- * @throw if there is an error with the underlying output stream. simdjson itself will not throw.
+ * @throw if there is an error with the underlying output stream. simdjson
+ * itself will not throw.
  */
-inline std::ostream& operator<<(std::ostream& out, simdjson::dom::object value);
+inline std::ostream &operator<<(std::ostream &out, simdjson::dom::object value);
 #if SIMDJSON_EXCEPTIONS
-inline std::ostream& operator<<(std::ostream& out,  simdjson::simdjson_result<simdjson::dom::object> x);
+inline std::ostream &
+operator<<(std::ostream &out,
+           simdjson::simdjson_result<simdjson::dom::object> x);
 #endif
 } // namespace dom
 
@@ -182,47 +244,47 @@ inline std::ostream& operator<<(std::ostream& out,  simdjson::simdjson_result<si
  *   cout << to_string(doc) << endl; // prints [1,2,3]
  *
  */
-template <class T>
-std::string to_string(T x)   {
-    // in C++, to_string is standard: http://www.cplusplus.com/reference/string/to_string/
-    // Currently minify and to_string are identical but in the future, they may
-    // differ.
-    simdjson::internal::string_builder<> sb;
-    sb.append(x);
-    std::string_view answer = sb.str();
-    return std::string(answer.data(), answer.size());
+template <class T> std::string to_string(T x) {
+  // in C++, to_string is standard:
+  // http://www.cplusplus.com/reference/string/to_string/ Currently minify and
+  // to_string are identical but in the future, they may differ.
+  simdjson::internal::string_builder<> sb;
+  sb.append(x);
+  std::string_view answer = sb.str();
+  return std::string(answer.data(), answer.size());
 }
 #if SIMDJSON_EXCEPTIONS
-template <class T>
-std::string to_string(simdjson_result<T> x) {
-    if (x.error()) { throw simdjson_error(x.error()); }
-    return to_string(x.value());
+template <class T> std::string to_string(simdjson_result<T> x) {
+  if (x.error()) {
+    throw simdjson_error(x.error());
+  }
+  return to_string(x.value());
 }
 #endif
 
 /**
- * Minifies a JSON element or document, printing the smallest possible valid JSON.
+ * Minifies a JSON element or document, printing the smallest possible valid
+ * JSON.
  *
  *   dom::parser parser;
  *   element doc = parser.parse("   [ 1 , 2 , 3 ] "_padded);
  *   cout << minify(doc) << endl; // prints [1,2,3]
  *
  */
-template <class T>
-std::string minify(T x)  {
-  return to_string(x);
-}
+template <class T> std::string minify(T x) { return to_string(x); }
 
 #if SIMDJSON_EXCEPTIONS
-template <class T>
-std::string minify(simdjson_result<T> x) {
-    if (x.error()) { throw simdjson_error(x.error()); }
-    return to_string(x.value());
+template <class T> std::string minify(simdjson_result<T> x) {
+  if (x.error()) {
+    throw simdjson_error(x.error());
+  }
+  return to_string(x.value());
 }
 #endif
 
 /**
- * Prettifies a JSON element or document, printing the valid JSON with indentation.
+ * Prettifies a JSON element or document, printing the valid JSON with
+ * indentation.
  *
  *   dom::parser parser;
  *   element doc = parser.parse("   [ 1 , 2 , 3 ] "_padded);
@@ -238,23 +300,22 @@ std::string minify(simdjson_result<T> x) {
  *   cout << prettify(doc) << endl;
  *
  */
-template <class T>
-std::string prettify(T x)  {
-    simdjson::internal::string_builder<simdjson::internal::pretty_formatter> sb;
-    sb.append(x);
-    std::string_view answer = sb.str();
-    return std::string(answer.data(), answer.size());
+template <class T> std::string prettify(T x) {
+  simdjson::internal::string_builder<simdjson::internal::pretty_formatter> sb;
+  sb.append(x);
+  std::string_view answer = sb.str();
+  return std::string(answer.data(), answer.size());
 }
 
 #if SIMDJSON_EXCEPTIONS
-template <class T>
-std::string prettify(simdjson_result<T> x) {
-    if (x.error()) { throw simdjson_error(x.error()); }
-    return to_string(x.value());
+template <class T> std::string prettify(simdjson_result<T> x) {
+  if (x.error()) {
+    throw simdjson_error(x.error());
+  }
+  return to_string(x.value());
 }
 #endif
 
 } // namespace simdjson
 
-
 #endif

include/simdjson/error-inl.h

@@ -67,8 +67,38 @@ simdjson_inline error_code simdjson_result_base<T>::error() const noexcept {
   return this->second;
 }
 
+
+template<typename T>
+simdjson_inline bool simdjson_result_base<T>::has_value() const noexcept {
+  return this->error() == SUCCESS;
+}
+
 #if SIMDJSON_EXCEPTIONS
 
+
+template<typename T>
+simdjson_inline T& simdjson_result_base<T>::operator*() &  noexcept(false) {
+  return this->value();
+}
+
+template<typename T>
+simdjson_inline T&& simdjson_result_base<T>::operator*() &&  noexcept(false) {
+  return std::forward<internal::simdjson_result_base<T>>(*this).value();
+}
+
+template<typename T>
+simdjson_inline T* simdjson_result_base<T>::operator->() noexcept(false) {
+  if (this->error()) { throw simdjson_error(this->error()); }
+  return &this->first;
+}
+
+
+template<typename T>
+simdjson_inline const T* simdjson_result_base<T>::operator->() const noexcept(false) {
+  if (this->error()) { throw simdjson_error(this->error()); }
+  return &this->first;
+}
+
 template<typename T>
 simdjson_inline T& simdjson_result_base<T>::value() & noexcept(false) {
   if (error()) { throw simdjson_error(error()); }
@@ -93,6 +123,7 @@ simdjson_inline simdjson_result_base<T>::operator T&&() && noexcept(false) {
 
 #endif // SIMDJSON_EXCEPTIONS
 
+
 template<typename T>
 simdjson_inline const T& simdjson_result_base<T>::value_unsafe() const& noexcept {
   return this->first;
@@ -128,7 +159,8 @@ simdjson_inline void simdjson_result<T>::tie(T &value, error_code &error) && noe
 }
 
 template<typename T>
-simdjson_warn_unused simdjson_inline error_code simdjson_result<T>::get(T &value) && noexcept {
+simdjson_warn_unused simdjson_inline error_code
+simdjson_result<T>::get(T &value) && noexcept {
   return std::forward<internal::simdjson_result_base<T>>(*this).get(value);
 }
 

include/simdjson/error.h

@@ -49,7 +49,8 @@ enum error_code {
   SCALAR_DOCUMENT_AS_VALUE,   ///< A scalar document is treated as a value.
   OUT_OF_BOUNDS,              ///< Attempted to access location outside of document.
   TRAILING_CONTENT,           ///< Unexpected trailing content in the JSON input
-  NUM_ERROR_CODES
+  OUT_OF_CAPACITY,            ///< The capacity was exceeded, we cannot allocate enough memory.
+  NUM_ERROR_CODES             ///< Placeholder for end of error code list.
 };
 
 /**
@@ -107,6 +108,10 @@ namespace internal {
 /**
  * The result of a simdjson operation that could fail.
  *
+ * IMPORTANT: For the ondemand API, we use implementation_simdjson_result_base<T> as a base class
+ * to avoid some compilation issue. Thus, if you modify this class, please ensure that the ondemand
+ * implementation_simdjson_result_base<T> is also modified.
+ *
  * Gives the option of reading error codes, or throwing an exception by casting to the desired result.
  *
  * This is a base class for implementations that want to add functions to the result type for
@@ -167,8 +172,27 @@ struct simdjson_result_base : protected std::pair<T, error_code> {
    */
   simdjson_inline error_code error() const noexcept;
 
+  /**
+   * Whether there is a value.
+   */
+  simdjson_inline bool has_value() const noexcept;
 #if SIMDJSON_EXCEPTIONS
 
+  /**
+   * Dereference operator to access the contained value.
+   *
+   * @throw simdjson_error if there was an error.
+   */
+  simdjson_inline T& operator*() &  noexcept(false);
+  simdjson_inline T&& operator*() &&  noexcept(false);
+  /**
+   * Arrow operator to access members of the contained value.
+   *
+   * @throw simdjson_error if there was an error.
+   */
+  simdjson_inline T* operator->() noexcept(false);
+  simdjson_inline const T* operator->() const noexcept(false);
+
   /**
    * Get the result value.
    *
@@ -196,17 +220,48 @@ struct simdjson_result_base : protected std::pair<T, error_code> {
    * @throw simdjson_error if there was an error.
    */
   simdjson_inline operator T&&() && noexcept(false);
+
 #endif // SIMDJSON_EXCEPTIONS
 
   /**
    * Get the result value. This function is safe if and only
    * the error() method returns a value that evaluates to false.
+   * We discourage the use of value_unsafe().
+   *
+   * The recommended pattern is:
+   *
+   * T value; // where T is the type
+   * auto error = result.get(value);
+   * if (error) {
+   *   // handle error
+   * }
+   *
+   * Or you may call 'value()' which will raise an exception
+   * in case of error:
+   *
+   * T value = result.value();
    */
   simdjson_inline const T& value_unsafe() const& noexcept;
 
   /**
    * Take the result value (move it). This function is safe if and only
    * the error() method returns a value that evaluates to false.
+   * We discourage the use of value_unsafe().
+   *
+   * The recommended pattern is:
+   *
+   * T value; // where T is the type
+   * auto error = result.get(value);
+   * if (error) {
+   *   // handle error, return, exit, abort
+   * } else {
+   *   // use value here.
+   * }
+   *
+   * Or you may call 'value()' which will raise an exception
+   * in case of error:
+   *
+   * T value = result.value();
    */
   simdjson_inline T&& value_unsafe() && noexcept;
 
@@ -221,6 +276,7 @@ struct simdjson_result_base : protected std::pair<T, error_code> {
  */
 template<typename T>
 struct simdjson_result : public internal::simdjson_result_base<T> {
+
   /**
    * @private Create a new empty result with error = UNINITIALIZED.
    */
@@ -253,13 +309,32 @@ struct simdjson_result : public internal::simdjson_result_base<T> {
    */
   simdjson_warn_unused simdjson_inline error_code get(T &value) && noexcept;
 
+  /**
+   * Copy the value to a provided std::string, only enabled for std::string_view.
+   *
+   * @param value The variable to assign the value to. May not be set if there is an error.
+   */
+  template <typename U = T>
+  simdjson_warn_unused simdjson_inline error_code get(std::string &value) && noexcept {
+    static_assert(std::is_same<U, std::string_view>::value, "SFINAE");
+    std::string_view v;
+    error_code error = std::forward<simdjson_result<T>>(*this).get(v);
+    if (!error) {
+      value.assign(v.data(), v.size());
+    }
+    return error;
+  }
+
   /**
    * The error.
    */
   simdjson_inline error_code error() const noexcept;
 
-#if SIMDJSON_EXCEPTIONS
 
+
+#if SIMDJSON_EXCEPTIONS
+  using internal::simdjson_result_base<T>::operator*;
+  using internal::simdjson_result_base<T>::operator->;
   /**
    * Get the result value.
    *

include/simdjson/fallback/stringparsing_defs.h

@@ -13,7 +13,7 @@ namespace {
 struct backslash_and_quote {
 public:
   static constexpr uint32_t BYTES_PROCESSED = 1;
-  simdjson_inline static backslash_and_quote copy_and_find(const uint8_t *src, uint8_t *dst);
+  simdjson_inline backslash_and_quote copy_and_find(const uint8_t *src, uint8_t *dst);
 
   simdjson_inline bool has_quote_first() { return c == '"'; }
   simdjson_inline bool has_backslash() { return c == '\\'; }
@@ -29,6 +29,24 @@ simdjson_inline backslash_and_quote backslash_and_quote::copy_and_find(const uin
   return { src[0] };
 }
 
+
+struct escaping {
+  static constexpr uint32_t BYTES_PROCESSED = 1;
+  simdjson_inline static escaping copy_and_find(const uint8_t *src, uint8_t *dst);
+
+  simdjson_inline bool has_escape() { return escape_bits; }
+  simdjson_inline int escape_index() { return 0; }
+
+  bool escape_bits;
+}; // struct escaping
+
+
+
+simdjson_inline escaping escaping::copy_and_find(const uint8_t *src, uint8_t *dst) {
+  dst[0] = src[0];
+  return { (src[0] == '\\') || (src[0] == '"') || (src[0] < 32) };
+}
+
 } // unnamed namespace
 } // namespace fallback
 } // namespace simdjson

include/simdjson/generic/implementation_simdjson_result_base-inl.h

@@ -29,12 +29,41 @@ simdjson_warn_unused simdjson_inline error_code implementation_simdjson_result_b
 }
 
 template<typename T>
-simdjson_inline error_code implementation_simdjson_result_base<T>::error() const noexcept {
+simdjson_warn_unused simdjson_inline error_code implementation_simdjson_result_base<T>::error() const noexcept {
   return this->second;
 }
 
+
+template<typename T>
+simdjson_warn_unused simdjson_inline bool implementation_simdjson_result_base<T>::has_value() const noexcept {
+  return this->error() == SUCCESS;
+}
+
 #if SIMDJSON_EXCEPTIONS
 
+template<typename T>
+simdjson_inline T& implementation_simdjson_result_base<T>::operator*() &  noexcept(false) {
+  return this->value();
+}
+
+template<typename T>
+simdjson_inline T&& implementation_simdjson_result_base<T>::operator*() &&  noexcept(false) {
+  return std::forward<implementation_simdjson_result_base<T>>(*this).value();
+}
+
+template<typename T>
+simdjson_inline T* implementation_simdjson_result_base<T>::operator->() noexcept(false) {
+  if (this->error()) { throw simdjson_error(this->error()); }
+  return &this->first;
+}
+
+
+template<typename T>
+simdjson_inline const T* implementation_simdjson_result_base<T>::operator->() const noexcept(false) {
+  if (this->error()) { throw simdjson_error(this->error()); }
+  return &this->first;
+}
+
 template<typename T>
 simdjson_inline T& implementation_simdjson_result_base<T>::value() & noexcept(false) {
   if (error()) { throw simdjson_error(error()); }

include/simdjson/generic/implementation_simdjson_result_base.h

@@ -67,12 +67,17 @@ struct implementation_simdjson_result_base {
    *
    * @param value The variable to assign the value to. May not be set if there is an error.
    */
-  simdjson_inline error_code get(T &value) && noexcept;
+  simdjson_warn_unused simdjson_inline error_code get(T &value) && noexcept;
 
   /**
    * The error.
    */
-  simdjson_inline error_code error() const noexcept;
+  simdjson_warn_unused simdjson_inline error_code error() const noexcept;
+
+  /**
+   * Whether there is a value.
+   */
+  simdjson_warn_unused simdjson_inline bool has_value() const noexcept;
 
 #if SIMDJSON_EXCEPTIONS
 
@@ -81,6 +86,16 @@ struct implementation_simdjson_result_base {
    *
    * @throw simdjson_error if there was an error.
    */
+  simdjson_inline T& operator*() &  noexcept(false);
+  simdjson_inline T&& operator*() &&  noexcept(false);
+  /**
+   * Arrow operator to access members of the contained value.
+   *
+   * @throw simdjson_error if there was an error.
+   */
+  simdjson_inline T* operator->() noexcept(false);
+  simdjson_inline const T* operator->() const noexcept(false);
+
   simdjson_inline T& value() & noexcept(false);
 
   /**
@@ -122,6 +137,7 @@ struct implementation_simdjson_result_base {
    * the error() method returns a value that evaluates to false.
    */
   simdjson_inline T&& value_unsafe() && noexcept;
+
 protected:
   /** users should never directly access first and second. **/
   T first{}; /** Users should never directly access 'first'. **/

include/simdjson/generic/numberparsing.h

@@ -361,7 +361,7 @@ simdjson_inline bool is_digit(const uint8_t c) {
   return static_cast<uint8_t>(c - '0') <= 9;
 }
 
-simdjson_inline error_code parse_decimal_after_separator(simdjson_unused const uint8_t *const src, const uint8_t *&p, uint64_t &i, int64_t &exponent) {
+simdjson_warn_unused simdjson_inline error_code parse_decimal_after_separator(simdjson_unused const uint8_t *const src, const uint8_t *&p, uint64_t &i, int64_t &exponent) {
   // we continue with the fiction that we have an integer. If the
   // floating point number is representable as x * 10^z for some integer
   // z that fits in 53 bits, then we will be able to convert back the
@@ -389,7 +389,7 @@ simdjson_inline error_code parse_decimal_after_separator(simdjson_unused const u
   return SUCCESS;
 }
 
-simdjson_inline error_code parse_exponent(simdjson_unused const uint8_t *const src, const uint8_t *&p, int64_t &exponent) {
+simdjson_warn_unused simdjson_inline error_code parse_exponent(simdjson_unused const uint8_t *const src, const uint8_t *&p, int64_t &exponent) {
   // Exp Sign: -123.456e[-]78
   bool neg_exp = ('-' == *p);
   if (neg_exp || '+' == *p) { p++; } // Skip + as well
@@ -478,7 +478,7 @@ static error_code slow_float_parsing(simdjson_unused const uint8_t * src, double
 
 /** @private */
 template<typename W>
-simdjson_inline error_code write_float(const uint8_t *const src, bool negative, uint64_t i, const uint8_t * start_digits, size_t digit_count, int64_t exponent, W &writer) {
+simdjson_warn_unused simdjson_inline error_code write_float(const uint8_t *const src, bool negative, uint64_t i, const uint8_t * start_digits, size_t digit_count, int64_t exponent, W &writer) {
   // If we frequently had to deal with long strings of digits,
   // we could extend our code by using a 128-bit integer instead
   // of a 64-bit integer. However, this is uncommon in practice.
@@ -541,13 +541,13 @@ simdjson_inline error_code write_float(const uint8_t *const src, bool negative,
 //
 // Our objective is accurate parsing (ULP of 0) at high speed.
 template<typename W>
-simdjson_inline error_code parse_number(const uint8_t *const src, W &writer);
+simdjson_warn_unused simdjson_inline error_code parse_number(const uint8_t *const src, W &writer);
 
 // for performance analysis, it is sometimes  useful to skip parsing
 #ifdef SIMDJSON_SKIPNUMBERPARSING
 
 template<typename W>
-simdjson_inline error_code parse_number(const uint8_t *const, W &writer) {
+simdjson_warn_unused simdjson_inline error_code parse_number(const uint8_t *const, W &writer) {
   writer.append_s64(0);        // always write zero
   return SUCCESS;              // always succeeds
 }
@@ -573,7 +573,7 @@ simdjson_unused simdjson_inline simdjson_result<number_type> get_number_type(con
 //
 // Our objective is accurate parsing (ULP of 0) at high speed.
 template<typename W>
-simdjson_inline error_code parse_number(const uint8_t *const src, W &writer) {
+simdjson_warn_unused simdjson_inline error_code parse_number(const uint8_t *const src, W &writer) {
   //
   // Check for minus sign
   //
@@ -647,7 +647,16 @@ simdjson_inline error_code parse_number(const uint8_t *const src, W &writer) {
   if (i > uint64_t(INT64_MAX)) {
     WRITE_UNSIGNED(i, src, writer);
   } else {
-    WRITE_INTEGER(negative ? (~i+1) : i, src, writer);
+#if SIMDJSON_MINUS_ZERO_AS_FLOAT
+    if(i == 0 && negative) {
+      // We have to write -0.0 instead of 0
+      WRITE_DOUBLE(-0.0, src, writer);
+    } else {
+      WRITE_INTEGER(negative ? (~i+1) : i, src, writer);
+    }
+#else
+  WRITE_INTEGER(negative ? (~i+1) : i, src, writer);
+#endif
   }
   if (jsoncharutils::is_not_structural_or_whitespace(*p)) { return INVALID_NUMBER(src); }
   return SUCCESS;
@@ -1108,6 +1117,12 @@ simdjson_unused simdjson_inline simdjson_result<number_type> get_number_type(con
       if (simdjson_unlikely(digit_count == 19 && memcmp(src, smaller_big_integer, 19) > 0)) {
         return number_type::big_integer;
       }
+#if SIMDJSON_MINUS_ZERO_AS_FLOAT
+      if(digit_count == 1 && src[0] == '0') {
+        // We have to write -0.0 instead of 0
+        return number_type::floating_point_number;
+      }
+#endif
       return number_type::signed_integer;
     }
     // Let us check if we have a big integer (>=2**64).

include/simdjson/generic/ondemand/amalgamated.h

@@ -14,6 +14,9 @@
 #include "simdjson/generic/ondemand/raw_json_string.h"
 #include "simdjson/generic/ondemand/parser.h"
 
+// JSON builder - needed for extract_into functionality
+#include "simdjson/generic/ondemand/json_string_builder.h"
+
 // All other declarations
 #include "simdjson/generic/ondemand/array.h"
 #include "simdjson/generic/ondemand/array_iterator.h"
@@ -45,4 +48,7 @@
 #include "simdjson/generic/ondemand/token_iterator-inl.h"
 #include "simdjson/generic/ondemand/value_iterator-inl.h"
 
+// JSON builder inline definitions
+#include "simdjson/generic/ondemand/json_string_builder-inl.h"
+#include "simdjson/generic/ondemand/json_builder.h"
 

include/simdjson/generic/ondemand/array-inl.h

@@ -85,7 +85,7 @@ simdjson_inline simdjson_result<array_iterator> array::begin() noexcept {
 simdjson_inline simdjson_result<array_iterator> array::end() noexcept {
   return array_iterator(iter);
 }
-simdjson_inline error_code array::consume() noexcept {
+simdjson_warn_unused simdjson_warn_unused simdjson_inline error_code array::consume() noexcept {
   auto error = iter.json_iter().skip_child(iter.depth()-1);
   if(error) { iter.abandon(); }
   return error;

include/simdjson/generic/ondemand/array.h

@@ -131,11 +131,42 @@ public:
    *         - INDEX_OUT_OF_BOUNDS if the array index is larger than an array length
    */
   simdjson_inline simdjson_result<value> at(size_t index) noexcept;
+
+#if SIMDJSON_SUPPORTS_CONCEPTS
+  /**
+   * Get this array as the given type.
+   *
+   * @param out This is set to a value of the given type, parsed from the JSON. If there is an error, this may not be initialized.
+   * @returns INCORRECT_TYPE If the JSON array is not of the given type.
+   * @returns SUCCESS If the parse succeeded and the out parameter was set to the value.
+   */
+  template <typename T>
+  simdjson_warn_unused simdjson_inline error_code get(T &out)
+     noexcept(custom_deserializable<T, array> ? nothrow_custom_deserializable<T, array> : true) {
+    static_assert(custom_deserializable<T, array>);
+    return deserialize(*this, out);
+  }
+  /**
+   * Get this array as the given type.
+   *
+   * @returns A value of the given type, parsed from the JSON.
+   * @returns INCORRECT_TYPE If the JSON value is not the given type.
+   */
+  template <typename T>
+  simdjson_inline simdjson_result<T> get()
+    noexcept(custom_deserializable<T, value> ? nothrow_custom_deserializable<T, value> : true)
+  {
+    static_assert(std::is_default_constructible<T>::value, "The specified type is not default constructible.");
+    T out{};
+    SIMDJSON_TRY(get<T>(out));
+    return out;
+  }
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
 protected:
   /**
    * Go to the end of the array, no matter where you are right now.
    */
-  simdjson_inline error_code consume() noexcept;
+  simdjson_warn_unused simdjson_inline error_code consume() noexcept;
 
   /**
    * Begin array iteration.
@@ -209,7 +240,28 @@ public:
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> at_pointer(std::string_view json_pointer) noexcept;
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> at_path(std::string_view json_path) noexcept;
   simdjson_inline simdjson_result<std::string_view> raw_json() noexcept;
+#if SIMDJSON_SUPPORTS_CONCEPTS
+  // TODO: move this code into object-inl.h
 
+  template<typename T>
+  simdjson_inline simdjson_result<T> get() noexcept {
+    if (error()) { return error(); }
+    if constexpr (std::is_same_v<T, SIMDJSON_IMPLEMENTATION::ondemand::array>) {
+      return first;
+    }
+    return first.get<T>();
+  }
+  template<typename T>
+  simdjson_warn_unused simdjson_inline error_code get(T& out) noexcept {
+    if (error()) { return error(); }
+    if constexpr (std::is_same_v<T, SIMDJSON_IMPLEMENTATION::ondemand::array>) {
+      out = first;
+    } else {
+      SIMDJSON_TRY( first.get<T>(out) );
+    }
+    return SUCCESS;
+  }
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
 };
 
 } // namespace simdjson

include/simdjson/generic/ondemand/array_iterator-inl.h

@@ -36,6 +36,9 @@ simdjson_inline array_iterator &array_iterator::operator++() noexcept {
   return *this;
 }
 
+simdjson_inline bool array_iterator::at_end() const noexcept {
+  return iter.at_end();
+}
 } // namespace ondemand
 } // namespace SIMDJSON_IMPLEMENTATION
 } // namespace simdjson
@@ -72,7 +75,9 @@ simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::array_iterato
   ++(first);
   return *this;
 }
-
+simdjson_inline bool simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::array_iterator>::at_end() const noexcept {
+  return !first.iter.is_valid() || first.at_end();
+}
 } // namespace simdjson
 
 #endif // SIMDJSON_GENERIC_ONDEMAND_ARRAY_ITERATOR_INL_H

include/simdjson/generic/ondemand/array_iterator.h

@@ -34,7 +34,8 @@ public:
    *
    * Part of the std::iterator interface.
    */
-  simdjson_inline simdjson_result<value> operator*() noexcept; // MUST ONLY BE CALLED ONCE PER ITERATION.
+  simdjson_inline simdjson_result<value>
+  operator*() noexcept; // MUST ONLY BE CALLED ONCE PER ITERATION.
   /**
    * Check if we are at the end of the JSON.
    *
@@ -58,6 +59,11 @@ public:
    */
   simdjson_inline array_iterator &operator++() noexcept;
 
+  /**
+   * Check if the array is at the end.
+   */
+  simdjson_warn_unused simdjson_inline bool at_end() const noexcept;
+
 private:
   value_iterator iter{};
 
@@ -76,7 +82,6 @@ namespace simdjson {
 
 template<>
 struct simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::array_iterator> : public SIMDJSON_IMPLEMENTATION::implementation_simdjson_result_base<SIMDJSON_IMPLEMENTATION::ondemand::array_iterator> {
-public:
   simdjson_inline simdjson_result(SIMDJSON_IMPLEMENTATION::ondemand::array_iterator &&value) noexcept; ///< @private
   simdjson_inline simdjson_result(error_code error) noexcept; ///< @private
   simdjson_inline simdjson_result() noexcept = default;
@@ -89,6 +94,8 @@ public:
   simdjson_inline bool operator==(const simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::array_iterator> &) const noexcept;
   simdjson_inline bool operator!=(const simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::array_iterator> &) const noexcept;
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::array_iterator> &operator++() noexcept;
+
+  simdjson_warn_unused simdjson_inline bool at_end() const noexcept;
 };
 
 } // namespace simdjson

include/simdjson/generic/ondemand/dependencies.h

@@ -8,6 +8,7 @@
 // Internal headers needed for ondemand generics.
 // All includes not under simdjson/generic/ondemand must be here!
 // Otherwise, amalgamation will fail.
+#include "simdjson/concepts.h"
 #include "simdjson/dom/base.h" // for MINIMAL_DOCUMENT_CAPACITY
 #include "simdjson/implementation.h"
 #include "simdjson/padded_string.h"

include/simdjson/generic/ondemand/deserialize.h

@@ -1,4 +1,4 @@
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
 
 #ifndef SIMDJSON_ONDEMAND_DESERIALIZE_H
 #ifndef SIMDJSON_CONDITIONAL_INCLUDE
@@ -7,55 +7,8 @@
 #include "simdjson/generic/ondemand/array.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE
 
-#include <concepts>
 namespace simdjson {
 
-namespace tag_invoke_fn_ns {
-void tag_invoke();
-
-struct tag_invoke_fn {
-  template <typename Tag, typename... Args>
-    requires requires(Tag tag, Args &&...args) {
-      tag_invoke(std::forward<Tag>(tag), std::forward<Args>(args)...);
-    }
-  constexpr auto operator()(Tag tag, Args &&...args) const
-      noexcept(noexcept(tag_invoke(std::forward<Tag>(tag),
-                                   std::forward<Args>(args)...)))
-          -> decltype(tag_invoke(std::forward<Tag>(tag),
-                                 std::forward<Args>(args)...)) {
-    return tag_invoke(std::forward<Tag>(tag), std::forward<Args>(args)...);
-  }
-};
-} // namespace tag_invoke_fn_ns
-
-inline namespace tag_invoke_ns {
-inline constexpr tag_invoke_fn_ns::tag_invoke_fn tag_invoke = {};
-} // namespace tag_invoke_ns
-
-template <typename Tag, typename... Args>
-concept tag_invocable = requires(Tag tag, Args... args) {
-  tag_invoke(std::forward<Tag>(tag), std::forward<Args>(args)...);
-};
-
-template <typename Tag, typename... Args>
-concept nothrow_tag_invocable =
-    tag_invocable<Tag, Args...> && requires(Tag tag, Args... args) {
-      {
-        tag_invoke(std::forward<Tag>(tag), std::forward<Args>(args)...)
-      } noexcept;
-    };
-
-template <typename Tag, typename... Args>
-using tag_invoke_result =
-    std::invoke_result<decltype(tag_invoke), Tag, Args...>;
-
-template <typename Tag, typename... Args>
-using tag_invoke_result_t =
-    std::invoke_result_t<decltype(tag_invoke), Tag, Args...>;
-
-template <auto &Tag> using tag_t = std::decay_t<decltype(Tag)>;
-
-
 struct deserialize_tag;
 
 /// These types are deserializable in a built-in way
@@ -77,7 +30,7 @@ template <typename T, typename ValT = SIMDJSON_IMPLEMENTATION::ondemand::value>
 concept custom_deserializable = tag_invocable<deserialize_tag, ValT&, T&>;
 
 template <typename T, typename ValT = SIMDJSON_IMPLEMENTATION::ondemand::value>
-concept deserializable = custom_deserializable<T, ValT> || is_builtin_deserializable_v<T>;
+concept deserializable = custom_deserializable<T, ValT> || is_builtin_deserializable_v<T> || concepts::optional_type<T>;
 
 template <typename T, typename ValT = SIMDJSON_IMPLEMENTATION::ondemand::value>
 concept nothrow_custom_deserializable = nothrow_tag_invocable<deserialize_tag, ValT&, T&>;
@@ -88,28 +41,44 @@ concept nothrow_deserializable = nothrow_custom_deserializable<T, ValT> || is_bu
 
 /// Deserialize Tag
 inline constexpr struct deserialize_tag {
+  using array_type = SIMDJSON_IMPLEMENTATION::ondemand::array;
+  using object_type = SIMDJSON_IMPLEMENTATION::ondemand::object;
   using value_type = SIMDJSON_IMPLEMENTATION::ondemand::value;
   using document_type = SIMDJSON_IMPLEMENTATION::ondemand::document;
   using document_reference_type = SIMDJSON_IMPLEMENTATION::ondemand::document_reference;
 
+  // Customization Point for array
+  template <typename T>
+    requires custom_deserializable<T, value_type>
+  simdjson_warn_unused constexpr /* error_code */ auto operator()(array_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, value_type>) {
+    return tag_invoke(*this, object, output);
+  }
+
+  // Customization Point for object
+  template <typename T>
+    requires custom_deserializable<T, value_type>
+  simdjson_warn_unused constexpr /* error_code */ auto operator()(object_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, value_type>) {
+    return tag_invoke(*this, object, output);
+  }
+
   // Customization Point for value
   template <typename T>
     requires custom_deserializable<T, value_type>
-  [[nodiscard]] constexpr /* error_code */ auto operator()(value_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, value_type>) {
+  simdjson_warn_unused constexpr /* error_code */ auto operator()(value_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, value_type>) {
     return tag_invoke(*this, object, output);
   }
 
   // Customization Point for document
   template <typename T>
     requires custom_deserializable<T, document_type>
-  [[nodiscard]] constexpr /* error_code */ auto operator()(document_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, document_type>) {
+  simdjson_warn_unused constexpr /* error_code */ auto operator()(document_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, document_type>) {
     return tag_invoke(*this, object, output);
   }
 
   // Customization Point for document reference
   template <typename T>
     requires custom_deserializable<T, document_reference_type>
-  [[nodiscard]] constexpr /* error_code */ auto operator()(document_reference_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, document_reference_type>) {
+  simdjson_warn_unused constexpr /* error_code */ auto operator()(document_reference_type &object, T& output) const noexcept(nothrow_custom_deserializable<T, document_reference_type>) {
     return tag_invoke(*this, object, output);
   }
 
@@ -119,5 +88,5 @@ inline constexpr struct deserialize_tag {
 } // namespace simdjson
 
 #endif // SIMDJSON_ONDEMAND_DESERIALIZE_H
-#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
 

include/simdjson/generic/ondemand/document-inl.h

@@ -141,7 +141,7 @@ simdjson_inline simdjson_result<std::string_view> document::get_string(bool allo
   return get_root_value_iterator().get_root_string(true, allow_replacement);
 }
 template <typename string_type>
-simdjson_inline error_code document::get_string(string_type& receiver, bool allow_replacement) noexcept {
+simdjson_warn_unused simdjson_inline error_code document::get_string(string_type& receiver, bool allow_replacement) noexcept {
   return get_root_value_iterator().get_root_string(receiver, true, allow_replacement);
 }
 simdjson_inline simdjson_result<std::string_view> document::get_wobbly_string() noexcept {
@@ -167,15 +167,15 @@ template<> simdjson_inline simdjson_result<int64_t> document::get() & noexcept {
 template<> simdjson_inline simdjson_result<bool> document::get() & noexcept { return get_bool(); }
 template<> simdjson_inline simdjson_result<value> document::get() & noexcept { return get_value(); }
 
-template<> simdjson_inline error_code document::get(array& out) & noexcept { return get_array().get(out); }
-template<> simdjson_inline error_code document::get(object& out) & noexcept { return get_object().get(out); }
-template<> simdjson_inline error_code document::get(raw_json_string& out) & noexcept { return get_raw_json_string().get(out); }
-template<> simdjson_inline error_code document::get(std::string_view& out) & noexcept { return get_string(false).get(out); }
-template<> simdjson_inline error_code document::get(double& out) & noexcept { return get_double().get(out); }
-template<> simdjson_inline error_code document::get(uint64_t& out) & noexcept { return get_uint64().get(out); }
-template<> simdjson_inline error_code document::get(int64_t& out) & noexcept { return get_int64().get(out); }
-template<> simdjson_inline error_code document::get(bool& out) & noexcept { return get_bool().get(out); }
-template<> simdjson_inline error_code document::get(value& out) & noexcept { return get_value().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(array& out) & noexcept { return get_array().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(object& out) & noexcept { return get_object().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(raw_json_string& out) & noexcept { return get_raw_json_string().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(std::string_view& out) & noexcept { return get_string(false).get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(double& out) & noexcept { return get_double().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(uint64_t& out) & noexcept { return get_uint64().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(int64_t& out) & noexcept { return get_int64().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(bool& out) & noexcept { return get_bool().get(out); }
+template<> simdjson_warn_unused simdjson_inline error_code document::get(value& out) & noexcept { return get_value().get(out); }
 
 template<> simdjson_deprecated simdjson_inline simdjson_result<raw_json_string> document::get() && noexcept { return get_raw_json_string(); }
 template<> simdjson_deprecated simdjson_inline simdjson_result<std::string_view> document::get() && noexcept { return get_string(false); }
@@ -195,8 +195,8 @@ simdjson_inline document::operator object() & noexcept(false) { return get_objec
 simdjson_inline document::operator uint64_t() noexcept(false) { return get_uint64(); }
 simdjson_inline document::operator int64_t() noexcept(false) { return get_int64(); }
 simdjson_inline document::operator double() noexcept(false) { return get_double(); }
-simdjson_inline document::operator std::string_view() noexcept(false) { return get_string(false); }
-simdjson_inline document::operator raw_json_string() noexcept(false) { return get_raw_json_string(); }
+simdjson_inline document::operator std::string_view() noexcept(false) simdjson_lifetime_bound { return get_string(false); }
+simdjson_inline document::operator raw_json_string() noexcept(false) simdjson_lifetime_bound { return get_raw_json_string(); }
 simdjson_inline document::operator bool() noexcept(false) { return get_bool(); }
 simdjson_inline document::operator value() noexcept(false) { return get_value(); }
 
@@ -245,7 +245,7 @@ simdjson_inline simdjson_result<value> document::operator[](const char *key) & n
   return start_or_resume_object()[key];
 }
 
-simdjson_inline error_code document::consume() noexcept {
+simdjson_warn_unused simdjson_inline error_code document::consume() noexcept {
   bool scalar = false;
   auto error = is_scalar().get(scalar);
   if(error) { return error; }
@@ -347,6 +347,54 @@ simdjson_inline simdjson_result<value> document::at_path(std::string_view json_p
   }
 }
 
+
+
+#if SIMDJSON_SUPPORTS_CONCEPTS && SIMDJSON_STATIC_REFLECTION
+
+template<constevalutil::fixed_string... FieldNames, typename T>
+  requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+simdjson_warn_unused simdjson_inline error_code document::extract_into(T& out) & noexcept {
+  // Helper to check if a field name matches any of the requested fields
+  auto should_extract = [](std::string_view field_name) constexpr -> bool {
+    return ((FieldNames.view() == field_name) || ...);
+  };
+
+  // Iterate through all members of T using reflection
+  template for (constexpr auto mem : std::define_static_array(
+      std::meta::nonstatic_data_members_of(^^T, std::meta::access_context::unchecked()))) {
+
+    if constexpr (!std::meta::is_const(mem) && std::meta::is_public(mem)) {
+      constexpr std::string_view key = std::define_static_string(std::meta::identifier_of(mem));
+
+      // Only extract this field if it's in our list of requested fields
+      if constexpr (should_extract(key)) {
+        // Try to find and extract the field
+        if constexpr (concepts::optional_type<decltype(out.[:mem:])>) {
+          // For optional fields, it's ok if they're missing
+          auto field_result = find_field_unordered(key);
+          if (!field_result.error()) {
+            auto error = field_result.get(out.[:mem:]);
+            if (error && error != NO_SUCH_FIELD) {
+              return error;
+            }
+          } else if (field_result.error() != NO_SUCH_FIELD) {
+            return field_result.error();
+          } else {
+            out.[:mem:].reset();
+          }
+        } else {
+          // For required fields (in the requested list), fail if missing
+          SIMDJSON_TRY((*this)[key].get(out.[:mem:]));
+        }
+      }
+    }
+  };
+
+  return SUCCESS;
+}
+
+#endif // SIMDJSON_SUPPORTS_CONCEPTS && SIMDJSON_STATIC_REFLECTION
+
 } // namespace ondemand
 } // namespace SIMDJSON_IMPLEMENTATION
 } // namespace simdjson
@@ -454,7 +502,7 @@ simdjson_inline simdjson_result<std::string_view> simdjson_result<SIMDJSON_IMPLE
   return first.get_string(allow_replacement);
 }
 template <typename string_type>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get_string(string_type& receiver, bool allow_replacement) noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get_string(string_type& receiver, bool allow_replacement) noexcept {
   if (error()) { return error(); }
   return first.get_string(receiver, allow_replacement);
 }
@@ -490,12 +538,12 @@ simdjson_deprecated simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_
   return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document>(first).get<T>();
 }
 template<typename T>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get(T &out) & noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get(T &out) & noexcept {
   if (error()) { return error(); }
   return first.get<T>(out);
 }
 template<typename T>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get(T &out) && noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get(T &out) && noexcept {
   if (error()) { return error(); }
   return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document>(first).get<T>(out);
 }
@@ -505,8 +553,8 @@ template<> simdjson_deprecated simdjson_inline simdjson_result<SIMDJSON_IMPLEMEN
   if (error()) { return error(); }
   return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document>(first);
 }
-template<> simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>(SIMDJSON_IMPLEMENTATION::ondemand::document &out) & noexcept = delete;
-template<> simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>(SIMDJSON_IMPLEMENTATION::ondemand::document &out) && noexcept {
+template<> simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>(SIMDJSON_IMPLEMENTATION::ondemand::document &out) & noexcept = delete;
+template<> simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>(SIMDJSON_IMPLEMENTATION::ondemand::document &out) && noexcept {
   if (error()) { return error(); }
   out = std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document>(first);
   return SUCCESS;
@@ -624,6 +672,15 @@ simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> simdjs
   return first.at_path(json_path);
 }
 
+#if SIMDJSON_STATIC_REFLECTION
+template<constevalutil::fixed_string... FieldNames, typename T>
+  requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::extract_into(T& out) & noexcept {
+  if (error()) { return error(); }
+  return first.extract_into<FieldNames...>(out);
+}
+#endif // SIMDJSON_STATIC_REFLECTION
+
 } // namespace simdjson
 
 
@@ -658,7 +715,7 @@ simdjson_inline simdjson_result<double> document_reference::get_double() noexcep
 simdjson_inline simdjson_result<double> document_reference::get_double_in_string() noexcept { return doc->get_root_value_iterator().get_root_double(false); }
 simdjson_inline simdjson_result<std::string_view> document_reference::get_string(bool allow_replacement) noexcept { return doc->get_root_value_iterator().get_root_string(false, allow_replacement); }
 template <typename string_type>
-simdjson_inline error_code document_reference::get_string(string_type& receiver, bool allow_replacement) noexcept { return doc->get_root_value_iterator().get_root_string(receiver, false, allow_replacement); }
+simdjson_warn_unused simdjson_inline error_code document_reference::get_string(string_type& receiver, bool allow_replacement) noexcept { return doc->get_root_value_iterator().get_root_string(receiver, false, allow_replacement); }
 simdjson_inline simdjson_result<std::string_view> document_reference::get_wobbly_string() noexcept { return doc->get_root_value_iterator().get_root_wobbly_string(false); }
 simdjson_inline simdjson_result<raw_json_string> document_reference::get_raw_json_string() noexcept { return doc->get_root_value_iterator().get_root_raw_json_string(false); }
 simdjson_inline simdjson_result<bool> document_reference::get_bool() noexcept { return doc->get_root_value_iterator().get_root_bool(false); }
@@ -711,7 +768,13 @@ simdjson_inline simdjson_result<value> document_reference::at_pointer(std::strin
 simdjson_inline simdjson_result<value> document_reference::at_path(std::string_view json_path) noexcept { return doc->at_path(json_path); }
 simdjson_inline simdjson_result<std::string_view> document_reference::raw_json() noexcept { return doc->raw_json();}
 simdjson_inline document_reference::operator document&() const noexcept { return *doc; }
-
+#if SIMDJSON_SUPPORTS_CONCEPTS && SIMDJSON_STATIC_REFLECTION
+template<constevalutil::fixed_string... FieldNames, typename T>
+  requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+simdjson_warn_unused simdjson_inline error_code document_reference::extract_into(T& out) & noexcept {
+  return doc->extract_into<FieldNames...>(out);
+}
+#endif // SIMDJSON_SUPPORTS_CONCEPTS && SIMDJSON_STATIC_REFLECTION
 } // namespace ondemand
 } // namespace SIMDJSON_IMPLEMENTATION
 } // namespace simdjson
@@ -808,7 +871,7 @@ simdjson_inline simdjson_result<std::string_view> simdjson_result<SIMDJSON_IMPLE
   return first.get_string(allow_replacement);
 }
 template <typename string_type>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get_string(string_type& receiver, bool allow_replacement) noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get_string(string_type& receiver, bool allow_replacement) noexcept {
   if (error()) { return error(); }
   return first.get_string(receiver, allow_replacement);
 }
@@ -843,12 +906,12 @@ simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::onde
   return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>(first).get<T>();
 }
 template <class T>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(T &out) & noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(T &out) & noexcept {
   if (error()) { return error(); }
   return first.get<T>(out);
 }
 template <class T>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(T &out) && noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(T &out) && noexcept {
   if (error()) { return error(); }
   return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>(first).get<T>(out);
 }
@@ -865,13 +928,13 @@ simdjson_inline simdjson_result<bool> simdjson_result<SIMDJSON_IMPLEMENTATION::o
   return first.is_string();
 }
 template <>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(SIMDJSON_IMPLEMENTATION::ondemand::document_reference &out) & noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(SIMDJSON_IMPLEMENTATION::ondemand::document_reference &out) & noexcept {
   if (error()) { return error(); }
   out = first;
   return SUCCESS;
 }
 template <>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(SIMDJSON_IMPLEMENTATION::ondemand::document_reference &out) && noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get(SIMDJSON_IMPLEMENTATION::ondemand::document_reference &out) && noexcept {
   if (error()) { return error(); }
   out = first;
   return SUCCESS;
@@ -959,7 +1022,14 @@ simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> simdjs
   }
   return first.at_path(json_path);
 }
-
+#if SIMDJSON_STATIC_REFLECTION
+template<constevalutil::fixed_string... FieldNames, typename T>
+  requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::extract_into(T& out) & noexcept {
+  if (error()) { return error(); }
+  return first.extract_into<FieldNames...>(out);
+}
+#endif // SIMDJSON_STATIC_REFLECTION
 } // namespace simdjson
 
 #endif // SIMDJSON_GENERIC_ONDEMAND_DOCUMENT_INL_H

include/simdjson/generic/ondemand/document.h

@@ -117,7 +117,7 @@ public:
    * @returns INCORRECT_TYPE if the JSON value is not a string. Otherwise, we return SUCCESS.
    */
   template <typename string_type>
-  simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
+  simdjson_warn_unused simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
   /**
    * Cast this JSON value to a string.
    *
@@ -183,7 +183,7 @@ public:
    */
   template <typename T>
   simdjson_inline simdjson_result<T> get() &
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
     noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
 #else
     noexcept
@@ -206,7 +206,7 @@ public:
    */
   template<typename T>
   simdjson_inline simdjson_result<T> get() &&
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
     noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
 #else
     noexcept
@@ -224,18 +224,18 @@ public:
    * Be mindful that the document instance must remain in scope while you are accessing object, array and value instances.
    *
    * @param out This is set to a value of the given type, parsed from the JSON. If there is an error, this may not be initialized.
-   * @returns INCORRECT_TYPE If the JSON value is not an object.
+   * @returns INCORRECT_TYPE If the JSON value is of the given type.
    * @returns SUCCESS If the parse succeeded and the out parameter was set to the value.
    */
   template<typename T>
-  simdjson_inline error_code get(T &out) &
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+  simdjson_warn_unused simdjson_inline error_code get(T &out) &
+#if SIMDJSON_SUPPORTS_CONCEPTS
     noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
 #else
     noexcept
 #endif
   {
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
     if constexpr (custom_deserializable<T, document>) {
         return deserialize(*this, out);
     } else {
@@ -247,7 +247,7 @@ public:
       static_cast<void>(out); // to get rid of unused errors
       return UNINITIALIZED;
     }
-#else // SIMDJSON_SUPPORTS_DESERIALIZATION
+#else // SIMDJSON_SUPPORTS_CONCEPTS
     // Unless the simdjson library or the user provides an inline implementation, calling this method should
     // immediately fail.
     static_assert(!sizeof(T), "The get method with given type is not implemented by the simdjson library. "
@@ -257,7 +257,7 @@ public:
       " You may also add support for custom types, see our documentation.");
     static_cast<void>(out); // to get rid of unused errors
     return UNINITIALIZED;
-#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
   }
 
   /** @overload template<typename T> error_code get(T &out) & noexcept */
@@ -322,7 +322,7 @@ public:
    *          time it parses a document or when it is destroyed.
    * @exception simdjson_error(INCORRECT_TYPE) if the JSON value is not a string.
    */
-  simdjson_inline operator std::string_view() noexcept(false);
+  simdjson_inline operator std::string_view() noexcept(false) simdjson_lifetime_bound;
   /**
    * Cast this JSON value to a raw_json_string.
    *
@@ -331,7 +331,7 @@ public:
    * @returns A pointer to the raw JSON for the given string.
    * @exception simdjson_error(INCORRECT_TYPE) if the JSON value is not a string.
    */
-  simdjson_inline operator raw_json_string() noexcept(false);
+  simdjson_inline operator raw_json_string() noexcept(false) simdjson_lifetime_bound;
   /**
    * Cast this JSON value to a bool.
    *
@@ -481,11 +481,27 @@ public:
    * E.g., you must still call "is_null()" to check that a value is null even if
    * "type()" returns json_type::null.
    *
+   * The answer can be one of
+   * simdjson::ondemand::json_type::object,
+   * simdjson::ondemand::json_type::array,
+   * simdjson::ondemand::json_type::string,
+   * simdjson::ondemand::json_type::number,
+   * simdjson::ondemand::json_type::boolean,
+   * simdjson::ondemand::json_type::null.
+   *
+   * Starting with simdjson 4.0, this function will return simdjson::ondemand::json_type::unknown
+   * given a bad token.
+   * This allows you to identify a case such as {"key": NaN} and identify the NaN value.
+   * The simdjson::ondemand::json_type::unknown value should only happen with non-valid JSON.
+   *
    * NOTE: If you're only expecting a value to be one type (a typical case), it's generally
    * better to just call .get_double, .get_string, etc. and check for INCORRECT_TYPE (or just
    * let it throw an exception).
    *
-   * @error TAPE_ERROR when the JSON value is a bad token like "}" "," or "alse".
+   * Prior to simdjson 4.0, this function would return an error given a bad token.
+   * Starting with simdjson 4.0, it will return simdjson::ondemand::json_type::unknown.
+   * This allows you to identify a case such as {"key": NaN} and identify the NaN value.
+   * The simdjson::ondemand::json_type::unknown value should only happen with non-valid JSON.
    */
   simdjson_inline simdjson_result<json_type> type() noexcept;
 
@@ -709,11 +725,41 @@ public:
    * the JSON document.
    */
   simdjson_inline simdjson_result<std::string_view> raw_json() noexcept;
+
+#if SIMDJSON_STATIC_REFLECTION
+  /**
+   * Extract only specific fields from the JSON object into a struct.
+   *
+   * This allows selective deserialization of only the fields you need,
+   * potentially improving performance by skipping unwanted fields.
+   *
+   * Example:
+   * ```c++
+   * struct Car {
+   *   std::string make;
+   *   std::string model;
+   *   int year;
+   *   double price;
+   * };
+   *
+   * Car car;
+   * doc.extract_into<"make", "model">(car);
+   * // Only 'make' and 'model' fields are extracted from JSON
+   * ```
+   *
+   * @tparam FieldNames Compile-time string literals specifying which fields to extract
+   * @param out The output struct to populate with selected fields
+   * @returns SUCCESS on success, or an error code if a required field is missing or has wrong type
+   */
+  template<constevalutil::fixed_string... FieldNames, typename T>
+    requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+  simdjson_warn_unused simdjson_inline error_code extract_into(T& out) & noexcept;
+#endif // SIMDJSON_STATIC_REFLECTION
 protected:
   /**
    * Consumes the document.
    */
-  simdjson_inline error_code consume() noexcept;
+  simdjson_warn_unused simdjson_inline error_code consume() noexcept;
 
   simdjson_inline document(ondemand::json_iterator &&iter) noexcept;
   simdjson_inline const uint8_t *text(uint32_t idx) const noexcept;
@@ -766,7 +812,7 @@ public:
   simdjson_inline simdjson_result<double> get_double_in_string() noexcept;
   simdjson_inline simdjson_result<std::string_view> get_string(bool allow_replacement = false) noexcept;
   template <typename string_type>
-  simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
+  simdjson_warn_unused simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
   simdjson_inline simdjson_result<std::string_view> get_wobbly_string() noexcept;
   simdjson_inline simdjson_result<raw_json_string> get_raw_json_string() noexcept;
   simdjson_inline simdjson_result<bool> get_bool() noexcept;
@@ -775,7 +821,7 @@ public:
   simdjson_inline simdjson_result<bool> is_null() noexcept;
   template <typename T>
   simdjson_inline simdjson_result<T> get() &
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
     noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
 #else
     noexcept
@@ -788,7 +834,7 @@ public:
   }
   template<typename T>
   simdjson_inline simdjson_result<T> get() &&
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
     noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
 #else
     noexcept
@@ -810,14 +856,14 @@ public:
    * @returns SUCCESS If the parse succeeded and the out parameter was set to the value.
    */
   template<typename T>
-  simdjson_inline error_code get(T &out) &
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+  simdjson_warn_unused simdjson_inline error_code get(T &out) &
+#if SIMDJSON_SUPPORTS_CONCEPTS
     noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document_reference> : true)
 #else
     noexcept
 #endif
   {
-#if SIMDJSON_SUPPORTS_DESERIALIZATION
+#if SIMDJSON_SUPPORTS_CONCEPTS
     if constexpr (custom_deserializable<T, document_reference>) {
         return deserialize(*this, out);
     } else {
@@ -829,7 +875,7 @@ public:
       static_cast<void>(out); // to get rid of unused errors
       return UNINITIALIZED;
     }
-#else // SIMDJSON_SUPPORTS_DESERIALIZATION
+#else // SIMDJSON_SUPPORTS_CONCEPTS
     // Unless the simdjson library or the user provides an inline implementation, calling this method should
     // immediately fail.
     static_assert(!sizeof(T), "The get method with given type is not implemented by the simdjson library. "
@@ -839,12 +885,17 @@ public:
       " You may also add support for custom types, see our documentation.");
     static_cast<void>(out); // to get rid of unused errors
     return UNINITIALIZED;
-#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+#endif // SIMDJSON_SUPPORTS_CONCEPTS
   }
 
   /** @overload template<typename T> error_code get(T &out) & noexcept */
   template<typename T> simdjson_inline error_code get(T &out) && noexcept;
   simdjson_inline simdjson_result<std::string_view> raw_json() noexcept;
+#if SIMDJSON_STATIC_REFLECTION
+  template<constevalutil::fixed_string... FieldNames, typename T>
+    requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+  simdjson_warn_unused simdjson_inline error_code extract_into(T& out) & noexcept;
+#endif // SIMDJSON_STATIC_REFLECTION
   simdjson_inline operator document&() const noexcept;
 #if SIMDJSON_EXCEPTIONS
   template <class T>
@@ -913,7 +964,7 @@ public:
   simdjson_inline simdjson_result<double> get_double_in_string() noexcept;
   simdjson_inline simdjson_result<std::string_view> get_string(bool allow_replacement = false) noexcept;
   template <typename string_type>
-  simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
+  simdjson_warn_unused simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
   simdjson_inline simdjson_result<std::string_view> get_wobbly_string() noexcept;
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::raw_json_string> get_raw_json_string() noexcept;
   simdjson_inline simdjson_result<bool> get_bool() noexcept;
@@ -926,6 +977,9 @@ public:
   template<typename T> simdjson_inline error_code get(T &out) & noexcept;
   template<typename T> simdjson_inline error_code get(T &out) && noexcept;
 #if SIMDJSON_EXCEPTIONS
+
+  using SIMDJSON_IMPLEMENTATION::implementation_simdjson_result_base<SIMDJSON_IMPLEMENTATION::ondemand::document>::operator*;
+  using SIMDJSON_IMPLEMENTATION::implementation_simdjson_result_base<SIMDJSON_IMPLEMENTATION::ondemand::document>::operator->;
   template <class T, typename std::enable_if<std::is_same<T, SIMDJSON_IMPLEMENTATION::ondemand::document>::value == false>::type>
   explicit simdjson_inline operator T() noexcept(false);
   simdjson_inline operator SIMDJSON_IMPLEMENTATION::ondemand::array() & noexcept(false);
@@ -965,6 +1019,11 @@ public:
 
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> at_pointer(std::string_view json_pointer) noexcept;
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> at_path(std::string_view json_path) noexcept;
+#if SIMDJSON_STATIC_REFLECTION
+  template<constevalutil::fixed_string... FieldNames, typename T>
+    requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+  simdjson_warn_unused simdjson_inline error_code extract_into(T& out) & noexcept;
+#endif // SIMDJSON_STATIC_REFLECTION
 };
 
 
@@ -991,7 +1050,7 @@ public:
   simdjson_inline simdjson_result<double> get_double_in_string() noexcept;
   simdjson_inline simdjson_result<std::string_view> get_string(bool allow_replacement = false) noexcept;
   template <typename string_type>
-  simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
+  simdjson_warn_unused simdjson_inline error_code get_string(string_type& receiver, bool allow_replacement = false) noexcept;
   simdjson_inline simdjson_result<std::string_view> get_wobbly_string() noexcept;
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::raw_json_string> get_raw_json_string() noexcept;
   simdjson_inline simdjson_result<bool> get_bool() noexcept;
@@ -1042,6 +1101,11 @@ public:
 
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> at_pointer(std::string_view json_pointer) noexcept;
   simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> at_path(std::string_view json_path) noexcept;
+#if SIMDJSON_STATIC_REFLECTION
+  template<constevalutil::fixed_string... FieldNames, typename T>
+    requires(std::is_class_v<T> && (sizeof...(FieldNames) > 0))
+  simdjson_warn_unused simdjson_inline error_code extract_into(T& out) & noexcept;
+#endif // SIMDJSON_STATIC_REFLECTION
 };
 
 

include/simdjson/generic/ondemand/document_stream-inl.h

@@ -182,10 +182,19 @@ simdjson_inline document_stream::iterator& document_stream::iterator::operator++
   return *this;
 }
 
+simdjson_inline bool document_stream::iterator::at_end() const noexcept {
+  return finished;
+}
+
+
 simdjson_inline bool document_stream::iterator::operator!=(const document_stream::iterator &other) const noexcept {
   return finished != other.finished;
 }
 
+simdjson_inline bool document_stream::iterator::operator==(const document_stream::iterator &other) const noexcept {
+  return finished == other.finished;
+}
+
 simdjson_inline document_stream::iterator document_stream::begin() noexcept {
   start();
   // If there are no documents, we're finished.
@@ -303,7 +312,10 @@ inline void document_stream::next_document() noexcept {
   // Always set depth=1 at the start of document
   doc.iter._depth = 1;
   // consume comma if comma separated is allowed
-  if (allow_comma_separated) { doc.iter.consume_character(','); }
+  if (allow_comma_separated) {
+    error_code ignored = doc.iter.consume_character(',');
+    static_cast<void>(ignored); // ignored on purpose
+  }
   // Resets the string buffer at the beginning, thus invalidating the strings.
   doc.iter._string_buf_loc = parser->string_buf.get();
   doc.iter._root = doc.iter.position();

include/simdjson/generic/ondemand/document_stream.h

@@ -131,6 +131,7 @@ public:
      * Default constructor.
      */
     simdjson_inline iterator() noexcept;
+    simdjson_inline iterator(const iterator &other) noexcept = default;
     /**
      * Get the current document (or error).
      */
@@ -144,6 +145,7 @@ public:
      * @param other the end iterator to compare to.
      */
     simdjson_inline bool operator!=(const iterator &other) const noexcept;
+    simdjson_inline bool operator==(const iterator &other) const noexcept;
     /**
      * @private
      *
@@ -187,6 +189,11 @@ public:
      */
      inline error_code error() const noexcept;
 
+     /**
+      * Returns whether the iterator is at the end.
+      */
+     inline bool at_end() const noexcept;
+
   private:
     simdjson_inline iterator(document_stream *s, bool finished) noexcept;
     /** The document_stream we're iterating through. */
@@ -198,6 +205,7 @@ public:
     friend class document_stream;
     friend class json_iterator;
   };
+  using iterator = document_stream::iterator;
 
   /**
    * Start iterating the documents in the stream.

include/simdjson/generic/ondemand/field-inl.h

@@ -114,7 +114,7 @@ simdjson_inline simdjson_result<std::string_view> simdjson_result<SIMDJSON_IMPLE
 }
 
 template<typename string_type>
-simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::field>::unescaped_key(string_type &receiver, bool allow_replacement) noexcept {
+simdjson_warn_unused simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::field>::unescaped_key(string_type &receiver, bool allow_replacement) noexcept {
   if (error()) { return error(); }
   return first.unescaped_key(receiver, allow_replacement);
 }