More documentation regarding builder (#2270 )

* minor update * more improvment to our documentation (builder branch) * putting back missing functions
General madness simpler, no simpler!!! (#2267 )
2026-06-08 17:27:07 +00:00 · 2024-10-04 01:47:13 -04:00 · 2024-10-02 09:50:06 -04:00 · 2024-09-26 17:20:44 -04:00 · 2024-09-25 12:33:04 -04:00 · 2024-09-24 14:47:58 -04:00
64 changed files with 11432 additions and 5699 deletions
@@ -25,7 +25,6 @@ CompileFlags:
 Diagnostics:
    Suppress:
        - pp_including_mainfile_in_preamble
-        - unused-includes
 ---
 # Amalgamated files that require or partly define an implementation
 If:
@@ -0,0 +1,29 @@
+name: Ubuntu ppc64le (GCC 11)
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: uraimo/run-on-arch-action@v2
+        name: Test
+        id: runcmd
+        with:
+          arch: aarch64
+          distro: ubuntu_latest
+          githubToken: ${{ github.token }}
+          install: |
+            apt-get update -q -y
+            apt-get install -y cmake make g++
+          run: |
+            cmake -DSIMDJSON_SANITIZE_UNDEFINED=ON -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -B build
+            cmake --build build -j=2
+            ctest --output-on-failure --test-dir build
@@ -17,7 +17,7 @@ jobs:
        fuzz-seconds: 600
        dry-run: false
    - name: Upload Crash
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
      if: failure() && steps.build.outcome == 'success'
      with:
        name: artifacts
@@ -24,7 +24,7 @@ jobs:
             echo "no trailing whitespace found, good!"
          fi
      - name: Archive whitespace patch
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
        if: always()
        with:
          name: whitespace-patch
@@ -22,7 +22,7 @@ jobs:
          - msystem: "MINGW64"
            install: mingw-w64-x86_64-cmake mingw-w64-x86_64-ninja mingw-w64-x86_64-gcc
            type: Debug
-            - msystem: "MINGW64"
+          - msystem: "MINGW64"
            install: mingw-w64-x86_64-cmake mingw-w64-x86_64-ninja mingw-w64-x86_64-gcc
            type: RelWithDebInfo
    env:
@@ -24,6 +24,6 @@ jobs:
            apt-get update -q -y
            apt-get install -y cmake make g++
          run: |
-            cmake -DCMAKE_BUILD_TYPE=Release -B build
+            cmake -DCMAKE_BUILD_TYPE=Release -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF  -B build
            cmake --build build -j=2
            ctest --output-on-failure --test-dir build
@@ -24,6 +24,6 @@ jobs:
            apt-get update -q -y
            apt-get install -y cmake make g++
          run: |
-            cmake -DCMAKE_BUILD_TYPE=Release -B build
+            cmake -DCMAKE_BUILD_TYPE=Release -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF  -B build
            cmake --build build -j=2
            ctest --output-on-failure --test-dir build
@@ -24,6 +24,6 @@ jobs:
            apt-get update -q -y
            apt-get install -y cmake make g++
          run: |
-            cmake -DCMAKE_BUILD_TYPE=Release -B build
+            cmake -DCMAKE_BUILD_TYPE=Release  -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -B build
            cmake --build build -j=2
            ctest --output-on-failure --test-dir build
@@ -0,0 +1,22 @@
+name: Ubuntu 24.04 CI (CXX 20)
+
+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_DEVELOPER_MODE=ON  -B build
+        env:
+          CXX: ${{matrix.cxx}}
+      - name: Build
+        run: cmake --build build -j=2
+      - name: Test
+        run: ctest --output-on-failure --test-dir build
@@ -26,15 +26,15 @@ jobs:
      run: |
        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}} -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -DBUILD_SHARED_LIBS=${{matrix.shared}} -B build
    - name: Build Debug
-      run: cmake --build build --config ${{build_type}} --verbose
+      run: cmake --build build --config ${{matrix.build_type}} --verbose
    - name: Run tests
      run: |
        cd build
-        ctest -C ${{build_type}}  -LE explicitonly  --output-on-failure
+        ctest -C ${{matrix.build_type}}  -LE explicitonly  --output-on-failure
    - name: Install
      run: |
-        cmake --install build --config ${{build_type}}
+        cmake --install build --config ${{matrix.build_type}}
    - name: Test Installation
      run: |
        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}}  -B build_install_test tests/installation_tests/find
-        cmake --build build_install_test --config ${{build_type}}
+        cmake --build build_install_test --config ${{matrix.build_type}}
@@ -0,0 +1,37 @@
+name: VS17-CLANG-CI
+
+on: [push, pull_request]
+
+jobs:
+  ci:
+    if: >-
+      ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
+      ! contains(toJSON(github.event.commits.*.message), '[skip github]')
+    name: windows-vs17
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: Debug}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: Release}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: RelWithDebInfo}
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: Configure
+      run: |
+        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}}  -T ClangCL -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -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
+    - name: Install
+      run: |
+        cmake --install build --config ${{matrix.build_type}}
+    - name: Test Installation
+      run: |
+        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}}  -B build_install_test tests/installation_tests/find
+        cmake --build build_install_test --config ${{matrix.build_type}}
@@ -13,15 +13,15 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - {gen: Visual Studio 17 2022, arch: x64, build_type: Debug, cxx: 17}
-          - {gen: Visual Studio 17 2022, arch: x64, build_type: Debug, cxx: 20}
-          - {gen: Visual Studio 17 2022, arch: x64, build_type: Release, cxx: 17}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: Debug}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: Release}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: RelWithDebInfo}
    steps:
    - name: checkout
      uses: actions/checkout@v4
    - name: Configure
      run: |
-        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}} -DSIMDJSON_CXX_STANDARD=${{matrix.cxx}} -T ClangCL -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -B build
+        cmake -G "${{matrix.gen}}" -A ${{matrix.arch}}  -T ClangCL -DSIMDJSON_DEVELOPER_MODE=ON -DSIMDJSON_COMPETITION=OFF -B build
    - name: Build
      run: cmake --build build --config ${{matrix.build_type}} --verbose
    - name: Run tests
@@ -109,11 +109,23 @@
        "numbers": "cpp",
        "semaphore": "cpp",
        "stop_token": "cpp",
-        "cfenv": "cpp"
-    },
-    "cmake.configureSettings": {
-        "CMAKE_EXPORT_COMPILE_COMMANDS": "YES",
-        "SIMDJSON_DEVELOPER_MODE": "ON",
-        "SIMDJSON_SINGLEHEADER": "OFF"
+        "cfenv": "cpp",
+        "format": "cpp",
+        "xlocmes": "cpp",
+        "xlocmon": "cpp",
+        "xlocnum": "cpp",
+        "xloctime": "cpp",
+        "xutility": "cpp",
+        "coroutine": "cpp",
+        "xfacet": "cpp",
+        "xhash": "cpp",
+        "xiosbase": "cpp",
+        "xlocale": "cpp",
+        "xlocbuf": "cpp",
+        "xlocinfo": "cpp",
+        "xmemory": "cpp",
+        "xstring": "cpp",
+        "xtr1common": "cpp",
+        "xtree": "cpp"
    }
 }
@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.14)
 project(
    simdjson
    # The version number is modified by tools/release.py
-    VERSION 3.10.1
+    VERSION 3.10.0
    DESCRIPTION "Parsing gigabytes of JSON per second"
    HOMEPAGE_URL "https://simdjson.org/"
    LANGUAGES CXX C
@@ -23,11 +23,7 @@ string(
 set(SIMDJSON_LIB_VERSION "23.0.0" CACHE STRING "simdjson library version")
 set(SIMDJSON_LIB_SOVERSION "23" 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)
-  message(WARNING "SIMDJSON_BUILD_STATIC_LIB only makes sense if BUILD_SHARED_LIBS is set to ON")
-  message(WARNING "You might be building and installing a two identical static libraries.")
-endif()
+option(SIMDJSON_BUILD_STATIC_LIB "Build simdjson_static library along with simdjson" OFF)

 option(SIMDJSON_ENABLE_THREADS "Link with thread support" ON)

@@ -55,7 +51,6 @@ endif()
 if(is_top_project)
  option(SIMDJSON_DEVELOPER_MODE "Enable targets for developing simdjson" OFF)
  option(BUILD_SHARED_LIBS "Build simdjson as a shared library" OFF)
-  option(SIMDJSON_SINGLEHEADER "Disable singleheader generation" ON)
 endif()

 include(cmake/handle-deprecations.cmake)
@@ -160,13 +155,11 @@ endif()
 include(CMakePackageConfigHelpers)
 include(GNUInstallDirs)

-if(SIMDJSON_SINGLEHEADER)
-  install(
-      FILES singleheader/simdjson.h
-      DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
-      COMPONENT simdjson_Development
-  )
-endif()
+install(
+    FILES singleheader/simdjson.h
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
+    COMPONENT simdjson_Development
+)

 install(
    TARGETS simdjson
@@ -210,7 +203,6 @@ if(SIMDJSON_BUILD_STATIC_LIB)
      TARGETS simdjson_static
      EXPORT simdjson_staticTargets
      ARCHIVE COMPONENT simdjson_Development
-      INCLUDES DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
  )
  install(
      EXPORT simdjson_staticTargets
@@ -294,9 +286,8 @@ add_subdirectory(tools)  ## This needs to be before tests because of cxxopts
 # most of the data has been moved to https://github.com/simdjson/simdjson-data
 add_subdirectory(jsonexamples)

-if(SIMDJSON_SINGLEHEADER)
+
 add_subdirectory(singleheader)
-endif()



@@ -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         = "3.10.1"
+PROJECT_NUMBER         = "3.10.0"

 # 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
@@ -201,8 +201,8 @@ For the video inclined, <br />
 Funding
 -------

-The work is supported by the Natural Sciences and Engineering Research Council of Canada under grants
-RGPIN-2017-03910 and RGPIN-2024-03787.
+The work is supported by the Natural Sciences and Engineering Research Council of Canada under grant
+number RGPIN-2017-03910.

 [license]: LICENSE
 [license img]: https://img.shields.io/badge/License-Apache%202-blue.svg
@@ -13,7 +13,7 @@ struct nlohmann_json {
    auto root = nlohmann::json::parse(json.data(), json.data() + json.size());
    for (auto tweet : root["statuses"]) {
      if (tweet["id"] == find_id) {
-        result = tweet["text"];
+        result = to_string(tweet["text"]);
        return true;
      }
    }
@@ -24,35 +24,6 @@ struct simdjson_ondemand {

 BENCHMARK_TEMPLATE(kostya, simdjson_ondemand)->UseManualTime();

-
-#if SIMDJSON_SUPPORTS_EXTRACT
-using namespace simdjson::ondemand;
-
-struct simdjson_ondemand_extract {
-  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);
-    for (ondemand::object object_point : doc.find_field("coordinates")) {
-      point p;
-      auto error = object_point.extract(
-        to{"x", p.x},
-        to{"y", p.y},
-        to{"z", p.z}
-      );
-      if(error) { return false; }
-      result.push_back(p);
-    }
-    return true;
-  }
-};
-
-BENCHMARK_TEMPLATE(kostya, simdjson_ondemand_extract)->UseManualTime();
-
-#endif // SIMDJSON_SUPPORTS_EXTRACT
-
 } // namespace kostya

 #endif // SIMDJSON_EXCEPTIONS
@@ -9,7 +9,7 @@ namespace partial_tweets {
 using namespace simdjson;

 struct simdjson_ondemand {
-  using StringType = std::string_view;
+  using StringType=std::string_view;

  ondemand::parser parser{};

@@ -43,47 +43,6 @@ struct simdjson_ondemand {

 BENCHMARK_TEMPLATE(partial_tweets, simdjson_ondemand)->UseManualTime();

-
-#if SIMDJSON_SUPPORTS_EXTRACT
-using namespace simdjson::ondemand;
-
-struct simdjson_ondemand_extract {
-  using StringType = std::string_view;
-  ondemand::parser parser{};
-  bool run(simdjson::padded_string &json, std::vector<tweet<std::string_view>> &result) {
-    // Walk the document, parsing the tweets as we go
-    auto doc = parser.iterate(json);
-    for (ondemand::object tweet_object : doc.find_field("statuses")) {
-      tweet<std::string_view> t;
-      auto error = tweet_object.extract(
-        to{"created_at", t.created_at},
-        to{"id", t.id},
-        to{"text", t.result},
-        to{"in_reply_to_status_id", [&t](auto val) {
-          if(val.is_null()) {
-            t.in_reply_to_status_id = 0;
-          } else {
-            t.in_reply_to_status_id = val;
-          }
-         }},
-        to{"user", sub{
-          to{"id", t.user.id},
-          to{"screen_name", t.user.screen_name},
-        }},
-        to{"retweet_count", t.retweet_count},
-        to{"favorite_count", t.favorite_count});
-        if(error) { return false; }
-        result.push_back(t);
-    }
-    return true;
-  }
-};
-
-BENCHMARK_TEMPLATE(partial_tweets, simdjson_ondemand_extract)->UseManualTime();
-
-
-#endif
-
 } // namespace partial_tweets

 #endif // SIMDJSON_EXCEPTIONS
@@ -26,8 +26,8 @@ struct nlohmann_json {
      }
    }

-    result.text = top_tweet["text"];
-    result.screen_name = top_tweet["user"]["screen_name"];
+    result.text = to_string(top_tweet["text"]);
+    result.screen_name = to_string(top_tweet["user"]["screen_name"]);
    return result.retweet_count != -1;
  }
 };
@@ -17,6 +17,8 @@ An overview of what you need to know to use simdjson, with examples.
  - [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)
@@ -526,7 +528,7 @@ support for users who avoid exceptions. See [the simdjson error handling documen
  double value;
  auto doc = parser.iterate(abstract_json);
  auto error = doc["str"]["123"]["abc"].get(value);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  cout << value << endl; // Prints 3.14
  ```
  This examples also show how we can string several operations and only check for the error once, a strategy we call  *error chaining*.
@@ -788,6 +790,18 @@ 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:
+
+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)*
+
+We describe both 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.
+
+### 1. Specialize `simdjson::ondemand::value::get` to get custom types (pre-C++20)
+
 Suppose you have your own types, such as a `Car` struct:

 ```C++
@@ -821,9 +835,15 @@ 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:
+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
+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
+// The code is unnecessary with C++20:
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
 simdjson::ondemand::value::get() noexcept {
@@ -839,6 +859,7 @@ simdjson::ondemand::value::get() noexcept {
  }
  return vec;
 }
+#endif
 ```

 We may then provide support for our `Car` struct:
@@ -850,26 +871,10 @@ simdjson_inline simdjson_result<Car> simdjson::ondemand::value::get() noexcept {
  auto error = get_object().get(obj);
  if (error) { return error; }
  Car car;
-  // Instead of repeatedly obj["something"], we iterate through the object which
-  // we expect to be faster.
-  for (auto field : obj) {
-    raw_json_string key;
-    error = field.key().get(key);
-    if (error) { return error; }
-    if (key == "make") {
-      error = field.value().get_string(car.make);
-      if (error) { return error; }
-    } else if (key == "model") {
-      error = field.value().get_string(car.model);
-      if (error) { return error; }
-    } else if (key == "year") {
-      error = field.value().get_int64().get(car.year);
-      if (error) { return error; }
-    } else if (key == "tire_pressure") {
-      error = field.value().get<std::vector<double>>().get(car.tire_pressure);
-      if (auto  error) { return error; }
-    }
-  }
+  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; }
+  if((error = obj["tire_pressure"].get<std::vector<double>>().get(car.tire_pressure))) { return error; }
  return car;
 }
 ```
@@ -893,6 +898,8 @@ struct Car {
  std::vector<double> tire_pressure;
 };

+#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+// This code is not necessary if you have a C++20 compliant system:
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
 simdjson::ondemand::value::get() noexcept {
@@ -908,7 +915,7 @@ simdjson::ondemand::value::get() noexcept {
  }
  return vec;
 }
-
+#endif

 template <>
 simdjson_inline simdjson_result<Car> simdjson::ondemand::value::get() noexcept {
@@ -916,26 +923,10 @@ simdjson_inline simdjson_result<Car> simdjson::ondemand::value::get() noexcept {
  auto error = get_object().get(obj);
  if (error) { return error; }
  Car car;
-  // Instead of repeatedly obj["something"], we iterate through the object which
-  // we expect to be faster.
-  for (auto field : obj) {
-    raw_json_string key;
-    error = field.key().get(key);
-    if (error) { return error; }
-    if (key == "make") {
-      error = field.value().get_string(car.make);
-      if (error) { return error; }
-    } else if (key == "model") {
-      error = field.value().get_string(car.model);
-      if (error) { return error; }
-    } else if (key == "year") {
-      error = field.value().get_int64().get(car.year);
-      if (error) { return error; }
-    } else if (key == "tire_pressure") {
-      error = field.value().get<std::vector<double>>().get(car.tire_pressure);
-      if (error) { return error; }
-    }
-  }
+  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; }
+  if((error = obj["tire_pressure"].get<std::vector<double>>().get(car.tire_pressure))) { return error; }
  return car;
 }

@@ -950,15 +941,14 @@ int main(void) {
  ondemand::parser parser;
  ondemand::document doc = parser.iterate(json);
  for (auto val : doc) {
-    Car c(val);
+    Car c(val); // an exception may be thrown
    std::cout << c.make << std::endl;
  }
-  direct();
  return EXIT_SUCCESS;
 }
 ```

-Observe that we require an explicit cast (`Car c(val)` instead of `for (Car c : doc) {`): it is by design.
+Observe that we require an explicit cast (`Car c(val)` instead of `for (Car c : doc) {`): it is by design. We require explicit casting.

 If you prefer to avoid exceptions, you may modify the `main` function as follows:

@@ -974,11 +964,11 @@ int main(void) {
  ondemand::parser parser;
  ondemand::document doc;
  auto error = parser.iterate(json).get(doc);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  for (auto val : doc) {
    Car c;
    error = val.get<Car>().get(c);
-    if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+    if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
    std::cout << c.make << std::endl;
  }
  return EXIT_SUCCESS;
@@ -1009,49 +999,49 @@ struct Car {
  std::vector<double> tire_pressure;
 };

+#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+// This code is not necessary if you have a C++20 compliant system:
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
 simdjson::ondemand::value::get() noexcept {
  ondemand::array array;
-  if (auto error = get_array().get(array); error) { return error; }
+  auto error = get_array().get(array);
+  if (error) { return error; }
  std::vector<double> vec;
  for (auto v : array) {
    double val;
-    if (auto error = v.get_double().get(val); error) { return error; }
+    error = v.get_double().get(val);
+    if (error) { return error; }
    vec.push_back(val);
  }
  return vec;
 }
-
+#endif

 template <>
 simdjson_inline simdjson_result<Car> simdjson::ondemand::document::get() & noexcept {
  ondemand::object obj;
  auto error = get_object().get(obj);
-  if (error) {
-    return error;
-  }
+  if (error) { return error; }
  Car car;
-  // Instead of repeatedly obj["something"], we iterate through the object which
-  // we expect to be faster.
-  for (auto field : obj) {
-    raw_json_string key;
-    error = field.key().get(key);
-    if (error) { return error; }
-    if (key == "make") {
-      error = field.value().get_string(car.make);
-      if (error) { return error; }
-    } else if (key == "model") {
-      error = field.value().get_string(car.model);
-      if (error) { return error; }
-    } else if (key == "year") {
-      error = field.value().get_int64().get(car.year);
-      if (error) { return error; }
-    } else if (key == "tire_pressure") {
-      error = field.value().get<std::vector<double>>().get(car.tire_pressure);
-      if (error) { return error; }
-    }
-  }
+  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; }
+  if((error = obj["tire_pressure"].get<std::vector<double>>().get(car.tire_pressure))) { return error; }
+  return car;
+}
+
+
+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; }
+  if((error = obj["tire_pressure"].get<std::vector<double>>().get(car.tire_pressure))) { return error; }
  return car;
 }

@@ -1066,6 +1056,219 @@ int main(void) {
 }
 ```

+### 2. Use `tag_invoke` for custom types (C++20)
+
+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.
+
+A tag_invoke function serves as a mechanism for customization points. It is not directly part of the C++ standard library but is often used in libraries that implement customization points.
+The tag_invoke function is typically a generic function that takes a tag type and additional arguments.
+The first argument is usually a tag type (often an empty struct) that uniquely identifies the customization point (e.g., deserialization of custom types in simdjson). Users or library providers can specialize tag_invoke for their types by defining it in the appropriate namespace, often inline namespace.
+
+
+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
+to 1, otherwise it is set to 0.
+
+Consider a custom class `Car`:
+
+```C++
+struct Car {
+  std::string make;
+  std::string model;
+  int year;
+  std::vector<float> tire_pressure;
+};
+```
+
+Observe how we defined 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.
+
+You may support deserializing directly from a JSON value or document to your own `Car` instance
+by defining a single `tag_invoke` function:
+
+
+```C++
+namespace simdjson {
+// This tag_invoke MUST be inside simdjson namespace
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, Car& car) {
+  ondemand::object obj;
+  auto error = val.get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  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(car.year))) {
+    return error;
+  }
+  if ((error = obj["tire_pressure"].get<std::vector<float>>().get(
+           car.tire_pressure))) {
+    return error;
+  }
+  return simdjson::SUCCESS;
+}
+} // namespace simdjson
+```
+
+Observe how we call `get<std::vector<float>>()` even though we never defined support
+for `std::vector<float>` in the simdjson library: it is all automated thanks to C++20 concepts.
+
+Importantly, the `tag_invoke` function must be inside the `simdjson` namespace.
+Let us explain each argument of `tag_invoke` function.
+
+- `simdjson::deserialize_tag`: it is the tag for Customization Point Object (CPO). You may often ignore this parameter. It is used to indicate that you mean to provide a deserialization function for simdjson.
+- `var`: It receives automatically a `simdjson` value type (document, value, document_reference).
+- The third parameter is an instance of the type that you want to support.
+
+You can use it like so:
+
+```cpp
+  simdjson::padded_string json =
+      R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  Car c(doc);
+  std::cout << c.make << std::endl;
+```
+
+Observe how we first get an instance of `document` and then we cast.
+
+You can also handle errors explicitly:
+
+```cpp
+  Car c;
+  auto error = doc.get(c);
+  if(error) { std::cerr << simdjson::error_message(error); return false; }
+  std::cout << c.make << std::endl;
+```
+
+You can also read instances of `Car` from an array or an object:
+```cpp
+  simdjson::padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  for (auto val : doc) {
+    Car c(val); // an exception may be thrown
+    std::cout << c.year << std::endl;
+  }
+```
+
+Observe how we first get a generic (`val`) which we cast to `Car`. It is by design: we require
+explicit casting. The cast may throw an exception.
+
+Once more, you can handle errors explicitly:
+
+```cpp
+  for (auto val : doc) {
+    Car c;
+    auto error = val.get(c);
+    if(error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
+  }
+```
+
+You can also use the custom `Car` type as part of a template such as `std::vector`:
+
+```cpp
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  std::vector<Car> cars(doc);
+  // visual studio users need an explicit call:
+  //   std::vector<Car> cars = doc.get<std::vector<Car>>();
+  // because the compiler does not know whether to convert
+  // doc to an unsigned int or to a vector.
+  for(Car& c : cars) {
+    std::cout << c.year << std::endl;
+  }
+```
+
+By default, we support a wide range of standard templates such as
+`std::vector`,  `std::list`, `std::set`, `std::stack`, `std:queue`,
+`std:deque`, `std::priority_queue`, `std::unordered_set`, `std::multiset`,
+`std::unordered_multiset`, `std::unique_ptr`, `std::shared_ptr`, `std::optional`,
+etc. They are handled automatically.
+
+E.g., you can recover an `std::unique_ptr<Car>` like so:
+```C++
+int main() {
+  auto const json = R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  std::unique_ptr<Car> c(doc);
+  std::cout << c->make << std::endl;
+  return EXIT_SUCCESS;
+}
+```
+
+You may also conditionally fill in `std::optional` values.
+
+```C++
+
+  padded_string json =
+      R"( { "car1": { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+})"_padded;
+  ondemand::parser parser;
+  ondemand::document doc = parser.iterate(json);
+  std::optional<Car> car;
+  error = doc["key not found"].get<std::optional<Car>>().get(car);
+  // car has no value, error != simdjson::SUCCESS
+  error = doc["car1"].get<std::optional<Car>>().get(car);
+  // car has value Car{"Toyota", "Camry", 2018, {40.1f, 39.9f}}
+  // error is simdjson::SUCCESS
+```
+
+And so forth.
+
+Advanced users may want to overwrite the defaults provided by the simdjson library.
+Suppose for example that you want to construct an instance of `std::list<Car>`, but
+you also want to filter out any car made by Toyota. You may provide your own
+`tag_invoke` function:
+
+```c++
+namespace simdjson {
+// suppose we want to filter out all Toyotas
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, std::list<Car>& car) {
+  ondemand::array arr;
+  auto error = val.get_array().get(arr);
+  if (error) {
+    return error;
+  }
+  for (auto v : arr) {
+    Car c;
+    if ((error = v.get<Car>().get(c))) {
+      return error;
+    }
+    if(c.make != "Toyota") {
+      car.push_back(c);
+    }
+  }
+  return simdjson::SUCCESS;
+}
+}
+```
+
+With this code, deserializing an `std::list<Car>` instance would capture only the cars
+that are not made by Toyota.
+

 Minifying JSON strings without parsing
 ----------------------
@@ -1081,6 +1284,7 @@ In some cases, you may have valid JSON strings that you do not wish to parse but
  std::unique_ptr<char[]> buffer{new char[length]};
  size_t new_length{}; // It will receive the minified length.
  auto error = simdjson::minify(some_string, length, buffer.get(), new_length);
+  if(error) { std::cerr << simdjson::error_message(error); }
  // The buffer variable now has "[1,2,3,4]" and new_length has value 9.
 ```

@@ -1278,7 +1482,7 @@ pair. You can retrieve the value with .get() without generating an exception, li
 ```c++
 ondemand::document doc;
 auto error = parser.iterate(json).get(doc);
-if (error) { cerr << error << endl; exit(1); }
+if(error) { std::cerr << simdjson::error_message(error); exit(1); }
 ```

 When there is no error, the error code `simdjson::SUCCESS`is returned: it evaluates as false as a Boolean.
@@ -1309,7 +1513,7 @@ bool simple_error_example() {
    auto error = doc["bad number"].get_double().get(x);
    // returns "simdjson::NUMBER_ERROR"
    if (error != SUCCESS) {
-      std::cout << error << std::endl;
+      std::cerr << simdjson::error_message(error) << std::endl;
      return false;
    }
    std::cout << "Got " << x << std::endl;
@@ -1343,7 +1547,7 @@ Notice how we can retrieve the exact error condition (in this instance `simdjson
 from the exception.

 We can write a "quick start" example where we attempt to parse the following JSON file and access some data, without triggering exceptions:
-```JavaScript
+```JSON
 {
  "statuses": [
    {
@@ -1362,7 +1566,6 @@ We can write a "quick start" example where we attempt to parse the following JSO
 Our program loads the file, selects value corresponding to key `"search_metadata"` which expected to be an object, and then
 it selects the key `"count"` within that object.

-
 ```C++
 #include <iostream>
 #include "simdjson.h"
@@ -1370,10 +1573,10 @@ it selects the key `"count"` within that object.
 int main(void) {
  simdjson::ondemand::parser parser;
  auto error = padded_string::load("twitter.json").get(json);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  simdjson::ondemand::document tweets;
  error = parser.iterate(json).get(tweets);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  simdjson::ondemand::value res;
  error = tweets["search_metadata"]["count"].get(res);
  if (error != SUCCESS) {
@@ -1404,12 +1607,12 @@ int main(void) {
  simdjson::ondemand::document tweets;
  padded_string json;
  auto error = padded_string::load("twitter.json").get(json);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  error = parser.iterate(json).get(tweets);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  uint64_t identifier;
  error = tweets["statuses"].at(0)["id"].get(identifier);
-  if (error) { std::cerr << error << std::endl; return EXIT_FAILURE; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return EXIT_FAILURE; }
  std::cout << identifier << std::endl;
 }
 ```
@@ -1433,40 +1636,40 @@ bool parse() {

  // Iterating through an array of objects
  auto error = parser.iterate(cars_json).get(doc);
-  if (error) { std::cerr << error << std::endl; return false; }
+  if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
  ondemand::array cars; // invalid until the get() succeeds
  error = doc.get_array().get(cars);

  for (auto car_value : cars) {
    ondemand::object car; // invalid until the get() succeeds
    error = car_value.get_object().get(car);
-    if (error) { std::cerr << error << std::endl; return false; }
+    if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }

    // Accessing a field by name
    std::string_view make;
    std::string_view model;
    error = car["make"].get(make);
-    if (error) { std::cerr << error << std::endl; return false; }
+    if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
    error = car["model"].get(model);
-    if (error) { std::cerr << error << std::endl; return false; }
+    if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }

    cout << "Make/Model: " << make << "/" << model << endl;

    // Casting a JSON element to an integer
    uint64_t year{};
    error = car["year"].get(year);
-    if (error) { std::cerr << error << std::endl; return false; }
+    if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
    cout << "- This car is " << 2020 - year << " years old." << endl;

    // Iterating through an array of floats
    double total_tire_pressure = 0;
    ondemand::array pressures;
    error = car["tire_pressure"].get_array().get(pressures);
-    if (error) { std::cerr << error << std::endl; return false; }
+    if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
    for (auto tire_pressure_value : pressures) {
      double tire_pressure;
      error = tire_pressure_value.get_double().get(tire_pressure);
-      if (error) { std::cerr << error << std::endl; return false; }
+      if (error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
      total_tire_pressure += tire_pressure;
    }
    cout << "- Average tire pressure: " << (total_tire_pressure / 4) << endl;
@@ -1588,7 +1791,7 @@ auto doc = parser.iterate(broken_json);
 int64_t i;
 auto error = doc["integer"].get_int64().get(i);    // Expect to get integer from "integer" key, but get TAPE_ERROR
 if (error) {
-  std::cout << error << std::endl;    // Prints TAPE_ERROR error message
+  std::cerr << simdjson::error_message(error) << std::endl;    // Prints TAPE_ERROR error message
  // Recover a pointer to the location of the first error:
  const char * ptr;
  doc.current_location().get(ptr);
@@ -1625,7 +1828,7 @@ auto doc = parser.iterate(json);
 int64_t i;
 auto error = doc["integer"].get_int64().get(i);    // Incorrect call on array, INCORRECT_TYPE error
 if (error) {
-  std::cout << error << std::endl;     // Prints INCORRECT_TYPE error message
+  std::cerr << simdjson::error_message(error) << std::endl;     // Prints INCORRECT_TYPE error message
  std::cout<< doc.current_location() << std::endl;  // Prints "[1,2,3] " (location of INCORRECT_TYPE error)
 }
 ```
@@ -1798,7 +2001,7 @@ for (auto doc: stream) {
    error = doc.at_pointer("/4").get(val);
    // error == simdjson::CAPACITY
    if (error) {
-      std::cerr << error << std::endl;
+      std::cerr << simdjson::error_message(error) << std::endl;
      // We left 293 bytes unprocessed at the tail end of the input.
      std::cout << " unprocessed bytes at the end: " << stream.truncated_bytes() << std::endl;
      break;
@@ -25,6 +25,7 @@ Contents
 - [Use cases](#use-cases)
 - [Tracking your position](#tracking-your-position)
 - [Incomplete streams](#incomplete-streams)
+- [C++20 features](#c20-features)

 Motivation
 -----------
@@ -288,3 +289,111 @@ string
 object
 array
 ```
+
+
+C++20 features
+--------------------
+
+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.
+
+A tag_invoke function serves as a mechanism for customization points. It is not directly part of the C++ standard library but is often used in libraries that implement customization points.
+The tag_invoke function is typically a generic function that takes a tag type and additional arguments.
+The first argument is usually a tag type (often an empty struct) that uniquely identifies the customization point (e.g., deserialization of custom types in simdjson). Users or library providers can specialize tag_invoke for their types by defining it in the appropriate namespace, often inline namespace.
+
+
+
+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
+the simdjson library.
+
+Consider a custom class `Car`:
+
+```C++
+struct Car {
+  std::string make;
+  std::string model;
+  int year;
+  std::vector<float> tire_pressure;
+};
+```
+
+
+You may support deserializing directly from a JSON value or document to your own `Car` instance
+by defining a single `tag_invoke` function:
+
+
+```C++
+namespace simdjson {
+// This tag_invoke MUST be inside simdjson namespace
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, Car& car) {
+  ondemand::object obj;
+  auto error = val.get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  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(car.year))) {
+    return error;
+  }
+  if ((error = obj["tire_pressure"].get<std::vector<float>>().get(
+           car.tire_pressure))) {
+    return error;
+  }
+  return simdjson::SUCCESS;
+}
+} // namespace simdjson
+```
+
+Importantly, the `tag_invoke` function must be inside the `simdjson` namespace.
+Let us explain each argument of `tag_invoke` function.
+
+- `simdjson::deserialize_tag`: it is the tag for Customization Point Object (CPO). You may often ignore this parameter. It is used to indicate that you mean to provide a deserialization function for simdjson.
+- `var`: It receives automatically a `simdjson` value type (document, value, document_reference).
+- The third parameter is an instance of the type that you want to support.
+
+Please see our main documentation (`basics.md`) under
+"Use `tag_invoke` for custom types (C++20)" for details about
+tag_invoke functions.
+
+Given a stream of JSON documents, you can add them to a data struture
+such as a `std::vector<Car>` like so if you support exceptions:
+
+```C++
+  padded_string json =
+      R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] }
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+)"_padded;
+  ondemand::parser parser;
+  ondemand::document_stream stream;
+  [[maybe_unused]] auto error = parser.iterate_many(json).get(stream);
+  std::vector<Car> cars;
+  for(auto doc : stream) {
+    cars.push_back((Car)doc); // an exception may be thrown
+  }
+```
+
+Otherwise you may use this longer version for explicit handling of errors:
+
+
+```C++
+  std::vector<Car> cars;
+  for(auto doc : stream) {
+    Car c;
+    if ((error = doc.get<Car>().get(c))) {
+      std::cerr << simdjson::error_message(error); << std::endl;
+      return EXIT_FAILURE;
+    }
+    cars.push_back(c);
+  }
+```
@@ -125,7 +125,7 @@ Whitespace Characters:
 - **Nothing**

 Some official formats **(non-exhaustive list)**:
- [Newline-Delimited JSON (NDJSON)](https://github.com/ndjson/ndjson-spec)
+- [Newline-Delimited JSON (NDJSON)](http://ndjson.org/)
 - [JSON lines (JSONL)](http://jsonlines.org/)
 - [Record separator-delimited JSON (RFC 7464)](https://tools.ietf.org/html/rfc7464) <- Not supported by JsonStream!
 - [More on Wikipedia...](https://en.wikipedia.org/wiki/JSON_streaming)
@@ -53,5 +53,4 @@

 #include "simdjson/dom.h"
 #include "simdjson/ondemand.h"
-
 #endif // SIMDJSON_H
@@ -9,6 +9,7 @@
 #include "simdjson/compiler_check.h"
 #include "simdjson/error.h"
 #include "simdjson/portability.h"
+#include "simdjson/concepts.h"

 /**
 * @brief The top level simdjson namespace, containing everything the library provides.
@@ -50,8 +50,6 @@ double from_chars(const char *first, const char* end) noexcept;
 #define SIMDJSON_ISALIGNED_N(ptr, n) (((uintptr_t)(ptr) & ((n)-1)) == 0)

 #if SIMDJSON_REGULAR_VISUAL_STUDIO
-  // We could use [[deprecated]] but it requires C++14
-  #define simdjson_deprecated __declspec(deprecated)

  #define simdjson_really_inline __forceinline
  #define simdjson_never_inline __declspec(noinline)
@@ -90,8 +88,6 @@ double from_chars(const char *first, const char* end) noexcept;
  #define SIMDJSON_POP_DISABLE_UNUSED_WARNINGS

 #else // SIMDJSON_REGULAR_VISUAL_STUDIO
-  // We could use [[deprecated]] but it requires C++14
-  #define simdjson_deprecated __attribute__((deprecated))

  #define simdjson_really_inline inline __attribute__((always_inline))
  #define simdjson_never_inline inline __attribute__((noinline))
@@ -56,12 +56,10 @@
 #endif
 #endif

-
-
-#if defined(__cpp_concepts)
-#define SIMDJSON_SUPPORTS_EXTRACT 1
-#else
-#define SIMDJSON_SUPPORTS_EXTRACT 0
+#ifdef __cpp_concepts
+#include <utility>
+#define SIMDJSON_SUPPORTS_DESERIALIZATION 1
+#else // __cpp_concepts
+#define SIMDJSON_SUPPORTS_DESERIALIZATION 0
 #endif
-
 #endif // SIMDJSON_COMPILER_CHECK_H
@@ -0,0 +1,113 @@
+#ifndef SIMDJSON_CONCEPTS_H
+#define SIMDJSON_CONCEPTS_H
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+
+#include <concepts>
+#include <type_traits>
+
+namespace simdjson {
+namespace concepts {
+
+namespace details {
+#define SIMDJSON_IMPL_CONCEPT(name, method)                                    \
+  template <typename T>                                                        \
+  concept supports_##name = !std::is_const_v<T> && requires {                  \
+    typename std::remove_cvref_t<T>::value_type;                               \
+    requires requires(typename std::remove_cvref_t<T>::value_type &&val,       \
+                      T obj) {                                                 \
+      obj.method(std::move(val));                                              \
+      requires !requires { obj = std::move(val); };                            \
+    };                                                                         \
+  };
+
+SIMDJSON_IMPL_CONCEPT(emplace_back, emplace_back);
+SIMDJSON_IMPL_CONCEPT(emplace, emplace);
+SIMDJSON_IMPL_CONCEPT(push_back, push_back);
+SIMDJSON_IMPL_CONCEPT(add, add);
+SIMDJSON_IMPL_CONCEPT(push, push);
+SIMDJSON_IMPL_CONCEPT(append, append);
+SIMDJSON_IMPL_CONCEPT(insert, insert);
+SIMDJSON_IMPL_CONCEPT(op_append, operator+=);
+
+#undef SIMDJSON_IMPL_CONCEPT
+} // namespace details
+
+/// Check if T is a container that we can append to, including:
+///   std::vector, std::deque, std::list, std::string, ...
+template <typename T>
+concept appendable_containers =
+    details::supports_emplace_back<T> || details::supports_emplace<T> ||
+    details::supports_push_back<T> || details::supports_push<T> ||
+    details::supports_add<T> || details::supports_append<T> ||
+    details::supports_insert<T>;
+
+/// Insert into the container however possible
+template <appendable_containers T, typename... Args>
+constexpr decltype(auto) emplace_one(T &vec, Args &&...args) {
+  if constexpr (details::supports_emplace_back<T>) {
+    return vec.emplace_back(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_emplace<T>) {
+    return vec.emplace(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_push_back<T>) {
+    return vec.push_back(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_push<T>) {
+    return vec.push(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_add<T>) {
+    return vec.add(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_append<T>) {
+    return vec.append(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_insert<T>) {
+    return vec.insert(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_op_append<T> && sizeof...(Args) == 1) {
+    return vec.operator+=(std::forward<Args>(args)...);
+  } else {
+    static_assert(!sizeof(T *),
+                  "We don't know how to add things to this container");
+  }
+}
+
+/// This checks if the container will return a reference to the newly added
+/// element after an insert which for example `std::vector::emplace_back` does
+/// since C++17; this will allow some optimizations.
+template <typename T>
+concept returns_reference = appendable_containers<T> && requires {
+  typename std::remove_cvref_t<T>::reference;
+  requires requires(typename std::remove_cvref_t<T>::value_type &&val, T obj) {
+    {
+      emplace_one(obj, std::move(val))
+    } -> std::same_as<typename std::remove_cvref_t<T>::reference>;
+  };
+};
+
+template <typename T>
+concept smart_pointer = requires(std::remove_cvref_t<T> ptr) {
+  // Check if T has a member type named element_type
+  typename std::remove_cvref_t<T>::element_type;
+
+  // Check if T has a get() member function
+  {
+    ptr.get()
+  } -> std::same_as<typename std::remove_cvref_t<T>::element_type *>;
+
+  // Check if T can be dereferenced
+  { *ptr } -> std::same_as<typename std::remove_cvref_t<T>::element_type &>;
+};
+
+template <typename T>
+concept optional_type = requires(std::remove_cvref_t<T> obj) {
+  typename std::remove_cvref_t<T>::value_type;
+  { 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
+};
+
+} // namespace concepts
+} // namespace simdjson
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+#endif // SIMDJSON_CONCEPTS_H
@@ -9,7 +9,7 @@ namespace simdjson {
 namespace fallback {
 namespace {

-#if SIMDJSON_REGULAR_VISUAL_STUDIO && !defined(_M_ARM64) && !defined(_M_X64)
+#if defined(_MSC_VER) && !defined(_M_ARM64) && !defined(_M_X64)
 static inline unsigned char _BitScanForward64(unsigned long* ret, uint64_t x) {
  unsigned long x0 = (unsigned long)x, top, bottom;
  _BitScanForward(&top, (unsigned long)(x >> 32));
@@ -28,7 +28,7 @@ static unsigned char _BitScanReverse64(unsigned long* ret, uint64_t x) {

 /* result might be undefined when input_num is zero */
 simdjson_inline int leading_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#ifdef _MSC_VER
  unsigned long leading_zero = 0;
  // Search the mask data from most significant bit (MSB)
  // to least significant bit (LSB) for a set bit (1).
@@ -38,7 +38,7 @@ simdjson_inline int leading_zeroes(uint64_t input_num) {
    return 64;
 #else
  return __builtin_clzll(input_num);
-#endif// SIMDJSON_REGULAR_VISUAL_STUDIO
+#endif// _MSC_VER
 }

 } // unnamed namespace
@@ -16,5 +16,4 @@
 #include "simdjson/internal/jsoncharutils_tables.h"
 #include "simdjson/internal/numberparsing_tables.h"
 #include "simdjson/internal/simdprune_tables.h"
-
 #endif // SIMDJSON_GENERIC_DEPENDENCIES_H
@@ -4,6 +4,7 @@

 // Stuff other things depend on
 #include "simdjson/generic/ondemand/base.h"
+#include "simdjson/generic/ondemand/deserialize.h"
 #include "simdjson/generic/ondemand/value_iterator.h"
 #include "simdjson/generic/ondemand/value.h"
 #include "simdjson/generic/ondemand/logger.h"
@@ -23,9 +24,13 @@
 #include "simdjson/generic/ondemand/object_iterator.h"
 #include "simdjson/generic/ondemand/serialization.h"

+// Deserialization for standard types
+#include "simdjson/generic/ondemand/std_deserialize.h"
+
 // Inline definitions
 #include "simdjson/generic/ondemand/array-inl.h"
 #include "simdjson/generic/ondemand/array_iterator-inl.h"
+#include "simdjson/generic/ondemand/value-inl.h"
 #include "simdjson/generic/ondemand/document-inl.h"
 #include "simdjson/generic/ondemand/document_stream-inl.h"
 #include "simdjson/generic/ondemand/field-inl.h"
@@ -38,5 +43,6 @@
 #include "simdjson/generic/ondemand/raw_json_string-inl.h"
 #include "simdjson/generic/ondemand/serialization-inl.h"
 #include "simdjson/generic/ondemand/token_iterator-inl.h"
-#include "simdjson/generic/ondemand/value-inl.h"
 #include "simdjson/generic/ondemand/value_iterator-inl.h"
+
+
@@ -0,0 +1,123 @@
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+
+#ifndef SIMDJSON_ONDEMAND_DESERIALIZE_H
+#ifndef SIMDJSON_CONDITIONAL_INCLUDE
+#define SIMDJSON_ONDEMAND_DESERIALIZE_H
+#include "simdjson/generic/ondemand/base.h"
+#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
+template <typename> struct is_builtin_deserializable : std::false_type {};
+template <> struct is_builtin_deserializable<int64_t> : std::true_type {};
+template <> struct is_builtin_deserializable<uint64_t> : std::true_type {};
+template <> struct is_builtin_deserializable<double> : std::true_type {};
+template <> struct is_builtin_deserializable<bool> : std::true_type {};
+template <> struct is_builtin_deserializable<SIMDJSON_IMPLEMENTATION::ondemand::array> : std::true_type {};
+template <> struct is_builtin_deserializable<SIMDJSON_IMPLEMENTATION::ondemand::object> : std::true_type {};
+template <> struct is_builtin_deserializable<SIMDJSON_IMPLEMENTATION::ondemand::value> : std::true_type {};
+template <> struct is_builtin_deserializable<SIMDJSON_IMPLEMENTATION::ondemand::raw_json_string> : std::true_type {};
+template <> struct is_builtin_deserializable<std::string_view> : std::true_type {};
+
+template <typename T>
+concept is_builtin_deserializable_v = is_builtin_deserializable<T>::value;
+
+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>;
+
+template <typename T, typename ValT = SIMDJSON_IMPLEMENTATION::ondemand::value>
+concept nothrow_custom_deserializable = nothrow_tag_invocable<deserialize_tag, ValT&, T&>;
+
+// built-in types are noexcept and if an error happens, the value simply gets ignored and the error is returned.
+template <typename T, typename ValT = SIMDJSON_IMPLEMENTATION::ondemand::value>
+concept nothrow_deserializable = nothrow_custom_deserializable<T, ValT> || is_builtin_deserializable_v<T>;
+
+/// Deserialize Tag
+inline constexpr struct deserialize_tag {
+  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 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>) {
+    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>) {
+    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>) {
+    return tag_invoke(*this, object, output);
+  }
+
+
+} deserialize{};
+
+} // namespace simdjson
+
+#endif // SIMDJSON_ONDEMAND_DESERIALIZE_H
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+
@@ -3,15 +3,19 @@
 #ifndef SIMDJSON_CONDITIONAL_INCLUDE
 #define SIMDJSON_GENERIC_ONDEMAND_DOCUMENT_INL_H
 #include "simdjson/generic/ondemand/base.h"
+#include "simdjson/generic/ondemand/array-inl.h"
 #include "simdjson/generic/ondemand/array_iterator.h"
 #include "simdjson/generic/ondemand/document.h"
+#include "simdjson/generic/ondemand/json_iterator-inl.h"
+#include "simdjson/generic/ondemand/json_path_to_pointer_conversion.h"
+#include "simdjson/generic/ondemand/json_path_to_pointer_conversion-inl.h"
 #include "simdjson/generic/ondemand/json_type.h"
+#include "simdjson/generic/ondemand/object-inl.h"
 #include "simdjson/generic/ondemand/raw_json_string.h"
 #include "simdjson/generic/ondemand/value.h"
-#include "simdjson/generic/ondemand/array-inl.h"
-#include "simdjson/generic/ondemand/json_iterator-inl.h"
-#include "simdjson/generic/ondemand/object-inl.h"
+#include "simdjson/generic/ondemand/value-inl.h"
 #include "simdjson/generic/ondemand/value_iterator-inl.h"
+#include "simdjson/generic/ondemand/deserialize.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE

 namespace simdjson {
@@ -165,26 +169,20 @@ 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_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); }
-template<> simdjson_deprecated simdjson_inline simdjson_result<double> document::get() && noexcept { return std::forward<document>(*this).get_double(); }
-template<> simdjson_deprecated simdjson_inline simdjson_result<uint64_t> document::get() && noexcept { return std::forward<document>(*this).get_uint64(); }
-template<> simdjson_deprecated simdjson_inline simdjson_result<int64_t> document::get() && noexcept { return std::forward<document>(*this).get_int64(); }
-template<> simdjson_deprecated simdjson_inline simdjson_result<bool> document::get() && noexcept { return std::forward<document>(*this).get_bool(); }
-template<> simdjson_deprecated 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<typename T> simdjson_inline error_code document::get(T &out) & noexcept {
-  return get<T>().get(out);
-}
-template<typename T> simdjson_deprecated simdjson_inline error_code document::get(T &out) && noexcept {
-  return std::forward<document>(*this).get<T>().get(out);
-}

 #if SIMDJSON_EXCEPTIONS
 template <class T>
-simdjson_deprecated simdjson_inline document::operator T() && noexcept(false) { return get<T>(); }
-template <class T>
-simdjson_inline document::operator T() & noexcept(false) { return get<T>(); }
+simdjson_inline document::operator T() noexcept(false) { return get<T>(); }
 simdjson_inline document::operator array() & noexcept(false) { return get_array(); }
 simdjson_inline document::operator object() & noexcept(false) { return get_object(); }
 simdjson_inline document::operator uint64_t() noexcept(false) { return get_uint64(); }
@@ -471,7 +469,7 @@ simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::onde
  return first.get<T>();
 }
 template<typename T>
-simdjson_deprecated simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get() && noexcept {
+simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get() && noexcept {
  if (error()) { return error(); }
  return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document>(first).get<T>();
 }
@@ -487,7 +485,7 @@ simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::do
 }

 template<> simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>() & noexcept = delete;
-template<> simdjson_deprecated simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>() && noexcept {
+template<> simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document>::get<SIMDJSON_IMPLEMENTATION::ondemand::document>() && noexcept {
  if (error()) { return error(); }
  return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document>(first);
 }
@@ -818,6 +816,26 @@ simdjson_inline simdjson_result<bool> simdjson_result<SIMDJSON_IMPLEMENTATION::o
  if (error()) { return error(); }
  return first.is_null();
 }
+template<typename T>
+simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get() & noexcept {
+  if (error()) { return error(); }
+  return first.get<T>();
+}
+template<typename T>
+simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::get() && noexcept {
+  if (error()) { return error(); }
+  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 {
+  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 {
+  if (error()) { return error(); }
+  return std::forward<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>(first).get<T>(out);
+}
 simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::json_type> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::type() noexcept {
  if (error()) { return error(); }
  return first.type();
@@ -830,6 +848,18 @@ simdjson_inline simdjson_result<bool> simdjson_result<SIMDJSON_IMPLEMENTATION::o
  if (error()) { return error(); }
  return first.is_string();
 }
+template <>
+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 {
+  if (error()) { return error(); }
+  out = first;
+  return SUCCESS;
+}
 simdjson_inline simdjson_result<bool> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::is_negative() noexcept {
  if (error()) { return error(); }
  return first.is_negative();
@@ -847,10 +877,12 @@ simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::number> simdj
  return first.get_number();
 }
 #if SIMDJSON_EXCEPTIONS
-template <class T, typename std::enable_if<std::is_same<T, SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::value == false>::type>
+template <class T>
 simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::operator T() noexcept(false) {
+  static_assert(std::is_same<T, SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::value == false, "You should not call get<T> when T is a document");
+  static_assert(std::is_same<T, SIMDJSON_IMPLEMENTATION::ondemand::document>::value == false, "You should not call get<T> when T is a document");
  if (error()) { throw simdjson_error(error()); }
-  return first;
+  return first.get<T>();
 }
 simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::operator SIMDJSON_IMPLEMENTATION::ondemand::array() & noexcept(false) {
  if (error()) { throw simdjson_error(error()); }
@@ -4,8 +4,11 @@
 #define SIMDJSON_GENERIC_ONDEMAND_DOCUMENT_H
 #include "simdjson/generic/ondemand/base.h"
 #include "simdjson/generic/ondemand/json_iterator.h"
+#include "simdjson/generic/ondemand/deserialize.h"
+#include "simdjson/generic/ondemand/value.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE

+
 namespace simdjson {
 namespace SIMDJSON_IMPLEMENTATION {
 namespace ondemand {
@@ -178,24 +181,39 @@ public:
   * @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 {
-    // 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. "
-      "The supported types are ondemand::object, ondemand::array, raw_json_string, std::string_view, uint64_t, "
-      "int64_t, double, and bool. We recommend you use get_double(), get_bool(), get_uint64(), get_int64(), "
-      " get_object(), get_array(), get_raw_json_string(), or get_string() instead of the get template."
-      " You may also add support for custom types, see our documentation.");
+  template <typename T>
+  simdjson_inline simdjson_result<T> get() &
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
+#else
+    noexcept
+#endif
+  {
+    static_assert(std::is_default_constructible<T>::value, "Cannot initialize the specified type.");
+    T out{};
+    SIMDJSON_TRY(get<T>(out));
+    return out;
  }
-  /** @overload template<typename T> simdjson_result<T> get() & noexcept */
-  template<typename T> simdjson_deprecated simdjson_inline simdjson_result<T> get() && noexcept {
-    // 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. "
-      "The supported types are ondemand::object, ondemand::array, raw_json_string, std::string_view, uint64_t, "
-      "int64_t, double, and bool. We recommend you use get_double(), get_bool(), get_uint64(), get_int64(), "
-      " get_object(), get_array(), get_raw_json_string(), or get_string() instead of the get template."
-      " You may also add support for custom types, see our documentation.");
+  /**
+   * @overload template<typename T> simdjson_result<T> get() & noexcept
+   *
+   * We disallow the use tag_invoke CPO on a moved document; it may create UB
+   * if user uses `ondemand::array` or `ondemand::object` in their custom type.
+   *
+   * The member function is still remains specialize-able for compatibility
+   * reasons, but we completely disallow its use when a tag_invoke customization
+   * is provided.
+   */
+  template<typename T>
+  simdjson_inline simdjson_result<T> get() &&
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
+#else
+    noexcept
+#endif
+  {
+      static_assert(!std::is_same<T, array>::value && !std::is_same<T, object>::value, "You should never hold either an ondemand::array or ondemand::object without a corresponding ondemand::document being alive; that would be Undefined Behaviour.");
+      return static_cast<document&>(*this).get<T>();
  }

  /**
@@ -209,9 +227,34 @@ public:
   * @returns INCORRECT_TYPE If the JSON value is not an object.
   * @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) & noexcept;
+  template<typename T>
+  simdjson_inline error_code get(T &out) &
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
+#else
+    noexcept
+#endif
+  {
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    if constexpr (custom_deserializable<T, document>) {
+        return deserialize(*this, out);
+    } else {
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+      // 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. "
+        "The supported types are ondemand::object, ondemand::array, raw_json_string, std::string_view, uint64_t, "
+        "int64_t, double, and bool. We recommend you use get_double(), get_bool(), get_uint64(), get_int64(), "
+        " get_object(), get_array(), get_raw_json_string(), or get_string() instead of the get template."
+        " You may also add support for custom types, see our documentation.");
+      static_cast<void>(out); // to get rid of unused errors
+      return UNINITIALIZED;
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    }
+#endif
+  }
  /** @overload template<typename T> error_code get(T &out) & noexcept */
-  template<typename T> simdjson_deprecated simdjson_inline error_code get(T &out) && noexcept;
+  template<typename T> simdjson_inline error_code get(T &out) && noexcept;

 #if SIMDJSON_EXCEPTIONS
  /**
@@ -224,10 +267,7 @@ public:
   * @returns An instance of type T
   */
  template <class T>
-  explicit simdjson_inline operator T() & noexcept(false);
-  template <class T>
-  explicit simdjson_deprecated simdjson_inline operator T() && noexcept(false);
-
+  explicit simdjson_inline operator T() noexcept(false);
  /**
   * Cast this JSON value to an array.
   *
@@ -716,7 +756,70 @@ public:
  simdjson_inline simdjson_result<value> get_value() noexcept;

  simdjson_inline simdjson_result<bool> is_null() noexcept;
-  template<typename T> simdjson_inline simdjson_result<T> get() & noexcept;
+  template <typename T>
+  simdjson_inline simdjson_result<T> get() &
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
+#else
+    noexcept
+#endif
+  {
+    static_assert(std::is_default_constructible<T>::value, "Cannot initialize the specified type.");
+    T out{};
+    SIMDJSON_TRY(get<T>(out));
+    return out;
+  }
+  template<typename T>
+  simdjson_inline simdjson_result<T> get() &&
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document> : true)
+#else
+    noexcept
+#endif
+  {
+      static_assert(!std::is_same<T, array>::value && !std::is_same<T, object>::value, "You should never hold either an ondemand::array or ondemand::object without a corresponding ondemand::document_reference being alive; that would be Undefined Behaviour.");
+      return static_cast<document&>(*this).get<T>();
+  }
+
+  /**
+   * Get this value as the given type.
+   *
+   * Supported types: object, array, raw_json_string, string_view, uint64_t, int64_t, double, bool, value
+   *
+   * 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 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
+    noexcept(custom_deserializable<T, document> ? nothrow_custom_deserializable<T, document_reference> : true)
+#else
+    noexcept
+#endif
+  {
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    if constexpr (custom_deserializable<T, document_reference>) {
+        return deserialize(*this, out);
+    } else {
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+      // 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. "
+        "The supported types are ondemand::object, ondemand::array, raw_json_string, std::string_view, uint64_t, "
+        "int64_t, double, and bool. We recommend you use get_double(), get_bool(), get_uint64(), get_int64(), "
+        " get_object(), get_array(), get_raw_json_string(), or get_string() instead of the get template."
+        " You may also add support for custom types, see our documentation.");
+      static_cast<void>(out); // to get rid of unused errors
+      return UNINITIALIZED;
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    }
+#endif
+  }
+  /** @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;
  simdjson_inline operator document&() const noexcept;
 #if SIMDJSON_EXCEPTIONS
@@ -793,7 +896,7 @@ public:
  simdjson_inline simdjson_result<bool> is_null() noexcept;

  template<typename T> simdjson_inline simdjson_result<T> get() & noexcept;
-  template<typename T> simdjson_deprecated simdjson_inline simdjson_result<T> get() && noexcept;
+  template<typename T> simdjson_inline simdjson_result<T> get() && noexcept;

  template<typename T> simdjson_inline error_code get(T &out) & noexcept;
  template<typename T> simdjson_inline error_code get(T &out) && noexcept;
@@ -868,8 +971,14 @@ public:
  simdjson_inline simdjson_result<bool> get_bool() noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> get_value() noexcept;
  simdjson_inline simdjson_result<bool> is_null() noexcept;
+
+  template<typename T> simdjson_inline simdjson_result<T> get() & noexcept;
+  template<typename T> simdjson_inline simdjson_result<T> get() && noexcept;
+
+  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
-  template <class T, typename std::enable_if<std::is_same<T, SIMDJSON_IMPLEMENTATION::ondemand::document_reference>::value == false>::type>
+  template <class T>
  explicit simdjson_inline operator T() noexcept(false);
  simdjson_inline operator SIMDJSON_IMPLEMENTATION::ondemand::array() & noexcept(false);
  simdjson_inline operator SIMDJSON_IMPLEMENTATION::ondemand::object() & noexcept(false);
@@ -152,7 +152,6 @@ simdjson_inline document_stream::iterator::iterator(document_stream* _stream, bo
 }

 simdjson_inline simdjson_result<ondemand::document_reference> document_stream::iterator::operator*() noexcept {
-  //if(stream->error) { return stream->error; }
  return simdjson_result<ondemand::document_reference>(stream->doc, stream->error);
 }

@@ -316,7 +316,7 @@ private:
  friend class document;
  friend class json_iterator;
  friend struct simdjson_result<ondemand::document_stream>;
-  friend struct simdjson::internal::simdjson_result_base<ondemand::document_stream>;
+  friend struct internal::simdjson_result_base<ondemand::document_stream>;
 };  // document_stream

 } // namespace ondemand
@@ -0,0 +1,67 @@
+#pragma once
+
+#ifndef SIMDJSON_ONDEMAND_GENERIC_JSON_PATH_TO_POINTER_CONVERSION_INL_H
+#define SIMDJSON_ONDEMAND_GENERIC_JSON_PATH_TO_POINTER_CONVERSION_INL_H
+
+#ifndef SIMDJSON_CONDITIONAL_INCLUDE
+#define SIMDJSON_GENERIC_ONDEMAND_JSON_PATH_TO_POINTER_CONVERSION_INL_H
+#include "simdjson/generic/ondemand/json_path_to_pointer_conversion.h"
+#endif // SIMDJSON_CONDITIONAL_INCLUDE
+
+namespace simdjson {
+namespace SIMDJSON_IMPLEMENTATION {}
+namespace ondemand {
+
+simdjson_inline std::string json_path_to_pointer_conversion(std::string_view json_path) {
+  if (json_path.empty() || (json_path.front() != '.' && json_path.front() != '[') {
+    return "-1"; // Sentinel value to be handled as an error by the caller.
+  }
+
+  std::string result;
+  // Reserve space to reduce allocations, adjusting for potential increases due
+  // to escaping.
+  result.reserve(json_path.size() * 2);
+
+  // Skip the initial '.' as it's assumed every path starts with it.
+  size_t i = 0;
+
+  while (i < json_path.length()) {
+    if (json_path[i] == '.') {
+      result += '/';
+    } else if (json_path[i] == '[') {
+      result += '/';
+      ++i; // Move past the '['
+      while (i < json_path.length() && json_path[i] != ']') {
+        if (json_path[i] == '~') {
+          result += "~0";
+        } else if (json_path[i] == '/') {
+          result += "~1";
+        } else {
+          result += json_path[i];
+        }
+        ++i;
+      }
+      if (i == json_path.length() || json_path[i] != ']') {
+        return "-1"; // Returning sentinel value that will be handled as an error by the caller
+      }
+    } else {
+      if (json_path[i] == '~') {
+        result += "~0";
+      } else if (json_path[i] == '/') {
+        result += "~1";
+      } else {
+        result += json_path[i];
+      }
+    }
+    ++i;
+  }
+
+  return simdjson_result<std::string>(result);
+}
+
+
+} // namespace ondemand
+} // namespace SIMDJSON_IMPLEMENTATION
+} // namespace simdjson
+
+#endif // SIMDJSON_ONDEMAND_GENERIC_JSON_PATH_TO_POINTER_CONVERSION_INL_H
@@ -0,0 +1,22 @@
+#pragma once
+
+#ifndef SIMDJSON_ONDEMAND_GENERIC_JSON_PATH_TO_POINTER_CONVERSION_H
+#define SIMDJSON_ONDEMAND_GENERIC_JSON_PATH_TO_POINTER_CONVERSION_H
+
+namespace simdjson {
+namespace SIMDJSON_IMPLEMENTATION {
+namespace internal {
+
+/**
+ * Converts JSONPath to JSON Pointer.
+ * @param json_path The JSONPath string to be converted.
+ * @return A string containing the equivalent JSON Pointer.
+ * @throws simdjson_error If the conversion fails.
+ */
+simdjson_inline std::string json_path_to_pointer_conversion(std::string_view json_path);
+
+} // namespace internal
+} // namespace SIMDJSON_IMPLEMENTATION
+} // namespace simdjson
+
+#endif // SIMDJSON_JSON_PATH_TO_POINTER_CONVERSION_H
@@ -15,141 +15,6 @@ namespace simdjson {
 namespace SIMDJSON_IMPLEMENTATION {
 namespace ondemand {

-
-#if SIMDJSON_SUPPORTS_EXTRACT
-
-
-#if SIMDJSON_REGULAR_VISUAL_STUDIO
-template <endpoint ...Funcs>
-simdjson_inline error_code object::extract(Funcs&&... endpoints) {
-  return iter.on_field_raw([&, eps = std::make_tuple(std::forward<Funcs>(endpoints)...)](auto field_key, error_code& error) mutable {
-    std::apply([&](auto &...endpoints) {
-       std::ignore = ((field_key.unsafe_is_equal(endpoints.key()) ? (error = endpoints(value(iter.child()))) == SUCCESS : true) && ...);
-    }, eps);
-    if (error) {
-      return true;
-    }
-    return false;
-  });
-}
-#else
-template <endpoint ...Funcs>
-simdjson_inline error_code object::extract(Funcs&&... endpoints) noexcept((nothrow_endpoint<Funcs> && ...)) {
-  return iter.on_field_raw([&](auto field_key, error_code& error) noexcept((nothrow_endpoint<Funcs> && ...)) {
-    std::ignore = ((field_key.unsafe_is_equal(endpoints.key()) ? (error = endpoints(value(iter.child()))) == SUCCESS : true) && ...);
-    if (error) {
-      return true;
-    }
-    return false;
-  });
-}
-#endif
-
-template <typename T>
-struct to {
-private:
-  T *pointer;
-  std::string_view m_key;
-
-public:
-  constexpr explicit(false)
-      to(std::string_view const inp_key, T &obj_ref) noexcept
-      : pointer{std::addressof(obj_ref)}, m_key{inp_key} {}
-
-  constexpr to(to const &) = default;
-  constexpr to(to &&) noexcept = default;
-  constexpr to &operator=(to const &) = default;
-  constexpr to &operator=(to &&) noexcept = default;
-  constexpr ~to() = default;
-
-  [[nodiscard]] constexpr std::string_view key() const noexcept {
-    return m_key;
-  }
-
-  [[nodiscard]] constexpr error_code operator()(simdjson_result<value> val) noexcept(
-      std::is_nothrow_assignable_v<T, simdjson_result<value>>) {
-    return val.get<T>(*pointer);
-  }
-};
-
-template <typename Func>
-  requires(std::is_invocable_v<Func, simdjson_result<value>>)
-struct to<Func> {
-private:
-  Func func;
-  std::string_view m_key;
-
-public:
-  constexpr explicit(false)
-      to(std::string_view const inp_key,
-         Func &&inp_func) noexcept(std::is_nothrow_copy_assignable_v<Func>)
-      : func{std::forward<Func>(inp_func)}, m_key{inp_key} {}
-
-  constexpr to(to const &) = default;
-  constexpr to(to &&) noexcept = default;
-  constexpr to& operator=(to const &) = default;
-  constexpr to& operator=(to &&) noexcept = default;
-  constexpr ~to() = default;
-
-  [[nodiscard]] constexpr std::string_view key() const noexcept {
-    return m_key;
-  }
-
-  [[nodiscard]] constexpr error_code operator()(simdjson_result<value> val) noexcept(
-      std::is_nothrow_invocable_v<Func, simdjson_result<value>>) {
-    if constexpr (std::is_invocable_r_v<error_code, Func, simdjson_result<value>>) {
-      return func(val);
-    } else {
-      static_cast<void>(func(val));
-      return SUCCESS;
-    }
-  }
-};
-
-template <typename Func>
-  requires(std::is_invocable_v<Func, simdjson_result<value>>)
-to(std::string_view, Func &&) -> to<Func>;
-
-template <typename T>
-to(std::string_view, T&) -> to<T>;
-
-template <endpoint... Tos>
-struct sub {
-private:
-  using tuple_type = std::tuple<Tos...>;
-  tuple_type tos;
-
-public:
-
-  // double templating to make perfect forwarding work
-  template <typename ...T>
-    requires ((std::same_as<T, Tos> && ...))
-  explicit constexpr sub(T&&...inp_tos) noexcept(std::is_nothrow_constructible_v<tuple_type, T...>)
-      : tos{std::forward<T>(inp_tos)...} {}
-
-  constexpr sub(sub const &) = default;
-  constexpr sub(sub &&) noexcept = default;
-  constexpr sub &operator=(sub const &) = default;
-  constexpr sub &operator=(sub &&) = default;
-  constexpr ~sub() = default;
-
-  [[nodiscard]] constexpr error_code operator()(simdjson_result<value> val) noexcept((nothrow_endpoint<Tos> && ...)) {
-    object obj;
-    if (auto const err = val.get_object().get(obj); err) {
-      return err;
-    }
-    return std::apply([&obj]<typename... T>(T &&...app_tos) {
-      return obj.extract(std::forward<T>(app_tos)...);
-    }, tos);
-  }
-};
-
-template <endpoint... Tos>
-sub(Tos&&...) -> sub<Tos...>;
-
-#endif
-
-
 simdjson_inline simdjson_result<value> object::find_field_unordered(const std::string_view key) & noexcept {
  bool has_value;
  SIMDJSON_TRY( iter.find_field_unordered_raw(key).get(has_value) );
@@ -11,19 +11,6 @@ namespace simdjson {
 namespace SIMDJSON_IMPLEMENTATION {
 namespace ondemand {

-#if SIMDJSON_SUPPORTS_EXTRACT
-
-template <typename T>
-concept endpoint = std::is_invocable_r_v<error_code, T, simdjson_result<value>> &&
-                   std::is_copy_constructible_v<T> && requires(T to) {
-                     { to.key() } noexcept -> std::convertible_to<std::string_view>;
-                   };
-
-template <typename T>
-concept nothrow_endpoint = endpoint<T> && std::is_nothrow_invocable_r_v<error_code, T, simdjson_result<value>>;
-
-#endif
-
 /**
 * A forward-only JSON object field iterator.
 */
@@ -78,21 +65,6 @@ public:
  /** @overload simdjson_inline simdjson_result<value> find_field(std::string_view key) & noexcept; */
  simdjson_inline simdjson_result<value> find_field(std::string_view key) && noexcept;

-#if SIMDJSON_SUPPORTS_EXTRACT
-  /**
-   * Extract all the fields in one go
-   * Funcs are invocables that take a simdjson_result<value> as input.
-   */
-  template <endpoint ...Funcs>
-  simdjson_inline error_code extract(Funcs&&... endpoints)
-#ifndef SIMDJSON_REGULAR_VISUAL_STUDIO // msvc thinks noexcept is not the same in definition
- noexcept((nothrow_endpoint<Funcs> && ...))
-#endif
- ;
-#endif
-
-
-
  /**
   * Look up a field by name on an object, without regard to key order.
   *
@@ -340,7 +340,7 @@ public:

 private:
  /** @private [for benchmarking access] The implementation to use */
-  std::unique_ptr<simdjson::internal::dom_parser_implementation> implementation{};
+  std::unique_ptr<internal::dom_parser_implementation> implementation{};
  size_t _capacity{0};
  size_t _max_capacity;
  size_t _max_depth{DEFAULT_MAX_DEPTH};
@@ -0,0 +1,166 @@
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+
+#ifndef SIMDJSON_ONDEMAND_DESERIALIZE_H
+#ifndef SIMDJSON_CONDITIONAL_INCLUDE
+#define SIMDJSON_ONDEMAND_DESERIALIZE_H
+#include "simdjson/generic/ondemand/array.h"
+#include "simdjson/generic/ondemand/base.h"
+#endif // SIMDJSON_CONDITIONAL_INCLUDE
+
+#include <concepts>
+#include <limits>
+
+namespace simdjson {
+template <typename T>
+constexpr bool require_custom_serialization = false;
+
+//////////////////////////////
+// Number deserialization
+//////////////////////////////
+
+template <std::unsigned_integral T>
+  requires(!require_custom_serialization<T>)
+error_code tag_invoke(deserialize_tag, auto &val, T &out) noexcept {
+  using limits = std::numeric_limits<T>;
+
+  uint64_t x;
+  SIMDJSON_TRY(val.get_uint64().get(x));
+  if (x > (limits::max)()) {
+    return NUMBER_OUT_OF_RANGE;
+  }
+  out = static_cast<T>(x);
+  return SUCCESS;
+}
+
+template <std::floating_point T>
+  requires(!require_custom_serialization<T>)
+error_code tag_invoke(deserialize_tag, auto &val, T &out) noexcept {
+  double x;
+  SIMDJSON_TRY(val.get_double().get(x));
+  out = static_cast<T>(x);
+  return SUCCESS;
+}
+
+template <std::signed_integral T>
+  requires(!require_custom_serialization<T>)
+error_code tag_invoke(deserialize_tag, auto &val, T &out) noexcept {
+  using limits = std::numeric_limits<T>;
+
+  int64_t x;
+  SIMDJSON_TRY(val.get_int64().get(x));
+  if (x > (limits::max)() || x < (limits::min)()) {
+    return NUMBER_OUT_OF_RANGE;
+  }
+  out = static_cast<T>(x);
+  return SUCCESS;
+}
+
+/**
+ * STL containers have several constructors including one that takes a single
+ * size argument. Thus, some compilers (Visual Studio) will not be able to
+ * disambiguate between the size and container constructor. Users should
+ * explicitly specify the type of the container as needed: e.g.,
+ * doc.get<std::vector<int>>().
+ */
+template <concepts::appendable_containers T, typename ValT>
+  requires(!require_custom_serialization<T>)
+error_code tag_invoke(deserialize_tag, ValT &val, T &out) noexcept(false) {
+  using value_type = typename std::remove_cvref_t<T>::value_type;
+  static_assert(
+      deserializable<value_type, ValT>,
+      "The specified type inside the container must itself be deserializable");
+  static_assert(
+      std::is_default_constructible_v<value_type>,
+      "The specified type inside the container must default constructible.");
+
+  SIMDJSON_IMPLEMENTATION::ondemand::array arr;
+  SIMDJSON_TRY(val.get_array().get(arr));
+  for (auto v : arr) {
+    if constexpr (concepts::returns_reference<T>) {
+      if (auto const err = v.get<value_type>().get(concepts::emplace_one(out));
+          err) {
+        // If an error occurs, the empty element that we just inserted gets
+        // removed. We're not using a temp variable because if T is a heavy
+        // type, we want the valid path to be the fast path and the slow path be
+        // the path that has errors in it.
+        if constexpr (requires { out.pop_back(); }) {
+          static_cast<void>(out.pop_back());
+        }
+        return err;
+      }
+    } else {
+      value_type temp;
+      if (auto const err = v.get<value_type>().get(temp); err) {
+        return err;
+      }
+      concepts::emplace_one(out, std::move(temp));
+    }
+  }
+  return SUCCESS;
+}
+
+
+
+/**
+ * This CPO (Customization Point Object) will help deserialize into
+ * smart pointers.
+ *
+ * If constructing T is nothrow, this conversion should be nothrow as well since
+ * we return MEMALLOC if we're not able to allocate memory instead of throwing
+ * the error message.
+ *
+ * @tparam T The type inside the smart pointer
+ * @tparam ValT document/value type
+ * @param val document/value
+ * @param out a reference to the smart pointer
+ * @return status of the conversion
+ */
+template <concepts::smart_pointer T, typename ValT>
+  requires(!require_custom_serialization<T>)
+error_code tag_invoke(deserialize_tag, ValT &val, T &out) noexcept(nothrow_deserializable<typename std::remove_cvref_t<T>::element_type, ValT>) {
+  using element_type = typename std::remove_cvref_t<T>::element_type;
+
+  // For better error messages, don't use these as constraints on
+  // the tag_invoke CPO.
+  static_assert(
+      deserializable<element_type, ValT>,
+      "The specified type inside the unique_ptr must itself be deserializable");
+  static_assert(
+      std::is_default_constructible_v<element_type>,
+      "The specified type inside the unique_ptr must default constructible.");
+
+  auto ptr = new (std::nothrow) element_type();
+  if (ptr == nullptr) {
+    return MEMALLOC;
+  }
+  SIMDJSON_TRY(val.template get<element_type>(*ptr));
+  out.reset(ptr);
+  return SUCCESS;
+}
+
+/**
+ * This CPO (Customization Point Object) will help deserialize into optional types.
+ */
+template <concepts::optional_type T, typename ValT>
+  requires(!require_custom_serialization<T>)
+error_code tag_invoke(deserialize_tag, ValT &val, T &out) noexcept(nothrow_deserializable<typename std::remove_cvref_t<T>::value_type, ValT>) {
+  using value_type = typename std::remove_cvref_t<T>::value_type;
+
+  static_assert(
+      deserializable<value_type, ValT>,
+      "The specified type inside the unique_ptr must itself be deserializable");
+  static_assert(
+      std::is_default_constructible_v<value_type>,
+      "The specified type inside the unique_ptr must default constructible.");
+
+  if (!out) {
+    out.emplace();
+  }
+  SIMDJSON_TRY(val.template get<value_type>(out.value()));
+  return SUCCESS;
+}
+
+} // namespace simdjson
+
+#endif // SIMDJSON_ONDEMAND_DESERIALIZE_H
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
@@ -6,6 +6,8 @@
 #include "simdjson/generic/ondemand/array.h"
 #include "simdjson/generic/ondemand/array_iterator.h"
 #include "simdjson/generic/ondemand/json_iterator.h"
+#include "simdjson/generic/ondemand/json_path_to_pointer_conversion.h"
+#include "simdjson/generic/ondemand/json_path_to_pointer_conversion-inl.h"
 #include "simdjson/generic/ondemand/json_type.h"
 #include "simdjson/generic/ondemand/object.h"
 #include "simdjson/generic/ondemand/raw_json_string.h"
@@ -78,6 +80,7 @@ simdjson_inline simdjson_result<bool> value::get_bool() noexcept {
 simdjson_inline simdjson_result<bool> value::is_null() noexcept {
  return iter.is_null();
 }
+
 template<> simdjson_inline simdjson_result<array> value::get() noexcept { return get_array(); }
 template<> simdjson_inline simdjson_result<object> value::get() noexcept { return get_object(); }
 template<> simdjson_inline simdjson_result<raw_json_string> value::get() noexcept { return get_raw_json_string(); }
@@ -88,9 +91,16 @@ template<> simdjson_inline simdjson_result<uint64_t> value::get() noexcept { ret
 template<> simdjson_inline simdjson_result<int64_t> value::get() noexcept { return get_int64(); }
 template<> simdjson_inline simdjson_result<bool> value::get() noexcept { return get_bool(); }

-template<typename T> simdjson_inline error_code value::get(T &out) noexcept {
-  return get<T>().get(out);
-}
+
+template<> simdjson_inline error_code value::get(array& out) noexcept { return get_array().get(out); }
+template<> simdjson_inline error_code value::get(object& out) noexcept { return get_object().get(out); }
+template<> simdjson_inline error_code value::get(raw_json_string& out) noexcept { return get_raw_json_string().get(out); }
+template<> simdjson_inline error_code value::get(std::string_view& out) noexcept { return get_string(false).get(out); }
+template<> simdjson_inline error_code value::get(number& out) noexcept { return get_number().get(out); }
+template<> simdjson_inline error_code value::get(double& out) noexcept { return get_double().get(out); }
+template<> simdjson_inline error_code value::get(uint64_t& out) noexcept { return get_uint64().get(out); }
+template<> simdjson_inline error_code value::get(int64_t& out) noexcept { return get_int64().get(out); }
+template<> simdjson_inline error_code value::get(bool& out) noexcept { return get_bool().get(out); }

 #if SIMDJSON_EXCEPTIONS
 template <class T>
@@ -414,6 +424,12 @@ simdjson_inline simdjson_result<bool> simdjson_result<SIMDJSON_IMPLEMENTATION::o
  return first.is_null();
 }

+template<> simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value>::get<SIMDJSON_IMPLEMENTATION::ondemand::value>(SIMDJSON_IMPLEMENTATION::ondemand::value &out) noexcept {
+  if (error()) { return error(); }
+  out = first;
+  return SUCCESS;
+}
+
 template<typename T> simdjson_inline simdjson_result<T> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value>::get() noexcept {
  if (error()) { return error(); }
  return first.get<T>();
@@ -427,11 +443,6 @@ template<> simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::va
  if (error()) { return error(); }
  return std::move(first);
 }
-template<> simdjson_inline error_code simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value>::get<SIMDJSON_IMPLEMENTATION::ondemand::value>(SIMDJSON_IMPLEMENTATION::ondemand::value &out) noexcept {
-  if (error()) { return error(); }
-  out = first;
-  return SUCCESS;
-}

 simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::json_type> simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value>::type() noexcept {
  if (error()) { return error(); }
@@ -465,7 +476,7 @@ simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::number> simdj
 template <class T>
 simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value>::operator T() noexcept(false) {
  if (error()) { throw simdjson_error(error()); }
-  return static_cast<T>(first);
+  return first.get<T>();
 }
 simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value>::operator SIMDJSON_IMPLEMENTATION::ondemand::array() noexcept(false) {
  if (error()) { throw simdjson_error(error()); }
@@ -5,12 +5,15 @@
 #include "simdjson/generic/ondemand/base.h"
 #include "simdjson/generic/implementation_simdjson_result_base.h"
 #include "simdjson/generic/ondemand/value_iterator.h"
+#include "simdjson/generic/ondemand/deserialize.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE

+#include <type_traits>
+
 namespace simdjson {
+
 namespace SIMDJSON_IMPLEMENTATION {
 namespace ondemand {
-
 /**
 * An ephemeral JSON value returned during iteration. It is only valid for as long as you do
 * not access more data in the JSON document.
@@ -35,16 +38,21 @@ public:
   * @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 {
-    // 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. "
-      "The supported types are ondemand::object, ondemand::array, raw_json_string, std::string_view, uint64_t, "
-      "int64_t, double, and bool. We recommend you use get_double(), get_bool(), get_uint64(), get_int64(), "
-      " get_object(), get_array(), get_raw_json_string(), or get_string() instead of the get template."
-      " You may also add support for custom types, see our documentation.");
+  template <typename T>
+  simdjson_inline simdjson_result<T> get()
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, value> ? nothrow_custom_deserializable<T, value> : true)
+#else
+    noexcept
+#endif
+  {
+    static_assert(std::is_default_constructible<T>::value, "The specified type is not default constructible.");
+    T out{};
+    SIMDJSON_TRY(get<T>(out));
+    return out;
  }

+
  /**
   * Get this value as the given type.
   *
@@ -54,7 +62,32 @@ public:
   * @returns INCORRECT_TYPE If the JSON value is not an object.
   * @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) noexcept;
+  template <typename T>
+  simdjson_inline error_code get(T &out)
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    noexcept(custom_deserializable<T, value> ? nothrow_custom_deserializable<T, value> : true)
+#else
+    noexcept
+#endif
+ {
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    if constexpr (custom_deserializable<T, value>) {
+      return deserialize(*this, out);
+    } else {
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+      // 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. "
+        "The supported types are ondemand::object, ondemand::array, raw_json_string, std::string_view, uint64_t, "
+        "int64_t, double, and bool. We recommend you use get_double(), get_bool(), get_uint64(), get_int64(), "
+        " get_object(), get_array(), get_raw_json_string(), or get_string() instead of the get template."
+        " You may also add support for custom types, see our documentation.");
+      static_cast<void>(out); // to get rid of unused errors
+      return UNINITIALIZED;
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+    }
+#endif
+  }

  /**
   * Cast this JSON value to an array.
@@ -1,4 +1,3 @@
-#include <type_traits>
 #ifndef SIMDJSON_GENERIC_ONDEMAND_VALUE_ITERATOR_INL_H

 #ifndef SIMDJSON_CONDITIONAL_INCLUDE
@@ -7,9 +6,9 @@
 #include "simdjson/generic/atomparsing.h"
 #include "simdjson/generic/numberparsing.h"
 #include "simdjson/generic/ondemand/json_iterator.h"
-#include "simdjson/generic/ondemand/value_iterator.h"
 #include "simdjson/generic/ondemand/json_type-inl.h"
 #include "simdjson/generic/ondemand/raw_json_string-inl.h"
+#include "simdjson/generic/ondemand/value_iterator.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE

 namespace simdjson {
@@ -110,108 +109,6 @@ simdjson_warn_unused simdjson_inline simdjson_result<bool> value_iterator::has_n
  }
 }

-template <typename Func>
-simdjson_warn_unused simdjson_inline error_code value_iterator::on_field_raw(Func&& func)
-#ifdef __cpp_lib_is_invocable
-  noexcept(std::is_nothrow_invocable_r_v<bool, Func, raw_json_string, error_code&>)
-#else
-  noexcept(false)
-#endif
-{
-#ifdef __cpp_lib_is_invocable
-  static_assert(std::is_invocable_r_v<bool, Func, raw_json_string, error_code&>, "Invalid function provided.");
-#endif
-
-  error_code error = SUCCESS;
-  bool has_value;
-  //
-  // Initially, the object can be in one of a few different places:
-  //
-  // 1. The start of the object, at the first field:
-  //
-  //    ```
-  //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
-  //      ^ (depth 2, index 1)
-  //    ```
-  if (at_first_field()) {
-    has_value = true;
-
-  //
-  // 2. When a previous search did not yield a value or the object is empty:
-  //
-  //    ```
-  //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
-  //                                     ^ (depth 0)
-  //    { }
-  //        ^ (depth 0, index 2)
-  //    ```
-  //
-  } else if (!is_open()) {
-#if SIMDJSON_DEVELOPMENT_CHECKS
-    // If we're past the end of the object, we're being iterated out of order.
-    // Note: this is not perfect detection. It's possible the user is inside some other object; if so,
-    // this object iterator will blithely scan that object for fields.
-    if (_json_iter->depth() < depth() - 1) { return OUT_OF_ORDER_ITERATION; }
-#endif
-    return EMPTY;
-
-  // 3. When a previous search found a field or an iterator yielded a value:
-  //
-  //    ```
-  //    // When a field was not fully consumed (or not even touched at all)
-  //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
-  //           ^ (depth 2)
-  //    // When a field was fully consumed
-  //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
-  //                   ^ (depth 1)
-  //    // When the last field was fully consumed
-  //    { "a": [ 1, 2 ], "b": [ 3, 4 ] }
-  //                                   ^ (depth 1)
-  //    ```
-  //
-  } else {
-    if ((error = skip_child() )) { abandon(); return error; }
-    if ((error = has_next_field().get(has_value) )) { abandon(); return error; }
-#if SIMDJSON_DEVELOPMENT_CHECKS
-    if (_json_iter->start_position(_depth) != start_position()) { return OUT_OF_ORDER_ITERATION; }
-#endif
-  }
-  while (has_value) {
-    // Get the key and colon, stopping at the value.
-    raw_json_string actual_key;
-    // size_t max_key_length = _json_iter->peek_length() - 2; // -2 for the two quotes
-    // Note: _json_iter->peek_length() - 2 might overflow if _json_iter->peek_length() < 2.
-    // field_key() advances the pointer and checks that '"' is found (corresponding to a key).
-    // The depth is left unchanged by field_key().
-    if ((error = field_key().get(actual_key) )) { abandon(); return error; };
-    // field_value() will advance and check that we find a ':' separating the
-    // key and the value. It will also increment the depth by one.
-    if ((error = field_value() )) { abandon(); return error; }
-    // If it matches, stop and return
-    // We could do it this way if we wanted to allow arbitrary
-    // key content (including escaped quotes).
-    //if (actual_key.unsafe_is_equal(max_key_length, key)) {
-    // Instead we do the following which may trigger buffer overruns if the
-    // user provides an adversarial key (containing a well placed unescaped quote
-    // character and being longer than the number of bytes remaining in the JSON
-    // input).
-    if (func(actual_key, error)) {
-      break;
-    }
-
-    // The call to skip_child is meant to skip over the value corresponding to the key.
-    // After skip_child(), we are right before the next comma (',') or the final brace ('}').
-    SIMDJSON_TRY( skip_child() ); // Skip the value entirely
-    // The has_next_field() advances the pointer and check that either ',' or '}' is found.
-    // It returns true if ',' is found, false otherwise. If anything other than ',' or '}' is found,
-    // then we are in error and we abort.
-    if ((error = has_next_field().get(has_value) )) { abandon(); return error; }
-  }
-
-  // If the loop ended, we're out of fields to look at.
-  return error;
-}
-
 simdjson_warn_unused simdjson_inline simdjson_result<bool> value_iterator::find_field_raw(const std::string_view key) noexcept {
  error_code error;
  bool has_value;
@@ -1191,4 +1088,4 @@ simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value_iterato

 } // namespace simdjson

-#endif // SIMDJSON_GENERIC_ONDEMAND_VALUE_ITERATOR_INL_H
+#endif // SIMDJSON_GENERIC_ONDEMAND_VALUE_ITERATOR_INL_H
@@ -6,12 +6,6 @@
 #include "simdjson/generic/implementation_simdjson_result_base.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE

-#ifdef __has_include
-#if __has_include (<version>)
-#include <version>
-#endif
-#endif
-
 namespace simdjson {
 namespace SIMDJSON_IMPLEMENTATION {
 namespace ondemand {
@@ -204,22 +198,6 @@ public:
   */
  simdjson_warn_unused simdjson_inline simdjson_result<bool> find_field_raw(const std::string_view key) noexcept;

-
-  /**
-   * Runs Func on each key found.
-   * Almost same as `find_field_raw` but it runs `func` instead of checking the key ourselves.
-   *
-   * @param Func func(raw_json_string key, error_code& error) noexcept
-   */
-  template <typename Func>
-  simdjson_warn_unused simdjson_inline error_code on_field_raw(Func&& func)
-#ifdef __cpp_lib_is_invocable
-  noexcept(std::is_nothrow_invocable_r_v<bool, Func, raw_json_string, error_code&>)
-#else
-  noexcept(false)
-#endif
-  ;
-
  /**
   * Find the field with the given key without regard to order, and *without* unescaping.
   *
@@ -511,4 +489,4 @@ public:

 } // namespace simdjson

-#endif // SIMDJSON_GENERIC_ONDEMAND_VALUE_ITERATOR_H
+#endif // SIMDJSON_GENERIC_ONDEMAND_VALUE_ITERATOR_H
@@ -53,9 +53,6 @@ inline padded_string::padded_string(const char *data, size_t length) noexcept
  if ((data != nullptr) && (data_ptr != nullptr)) {
    std::memcpy(data_ptr, data, length);
  }
-  if (data_ptr == nullptr) {
-    viable_size = 0;
-  }
 }
 #ifdef __cpp_char8_t
 inline padded_string::padded_string(const char8_t *data, size_t length) noexcept
@@ -63,17 +60,12 @@ inline padded_string::padded_string(const char8_t *data, size_t length) noexcept
  if ((data != nullptr) && (data_ptr != nullptr)) {
    std::memcpy(data_ptr, reinterpret_cast<const char *>(data), length);
  }
-  if (data_ptr == nullptr) {
-    viable_size = 0;
-  }
 }
 #endif
 // note: do not pass std::string arguments by value
 inline padded_string::padded_string(const std::string & str_ ) noexcept
    : viable_size(str_.size()), data_ptr(internal::allocate_padded_buffer(str_.size())) {
-  if (data_ptr == nullptr) {
-    viable_size = 0;
-  } else {
+  if (data_ptr != nullptr) {
    std::memcpy(data_ptr, str_.data(), str_.size());
  }
 }
@@ -4,7 +4,7 @@
 #define SIMDJSON_SIMDJSON_VERSION_H

 /** The version of simdjson being used (major.minor.revision) */
-#define SIMDJSON_VERSION "3.10.1"
+#define SIMDJSON_VERSION "3.10.0"

 namespace simdjson {
 enum {
@@ -19,7 +19,7 @@ enum {
  /**
   * The revision (major.minor.REVISION) of simdjson being used.
   */
-  SIMDJSON_VERSION_REVISION = 1
+  SIMDJSON_VERSION_REVISION = 0
 };
 } // namespace simdjson

@@ -1,4 +1,4 @@
-/* auto-generated on 2024-08-26 09:37:03 -0400. Do not edit! */
+/* auto-generated on 2024-09-30 10:57:33 -0400. Do not edit! */
 /* including simdjson.cpp:  */
 /* begin file simdjson.cpp */
 #define SIMDJSON_SRC_SIMDJSON_CPP
@@ -77,6 +77,18 @@
 #endif
 #endif

+#ifdef __has_include
+#if __has_include(<version>)
+#include <version>
+#endif
+#endif
+
+#ifdef __cpp_concepts
+#include <utility>
+#define SIMDJSON_SUPPORTS_DESERIALIZATION 1
+#else // __cpp_concepts
+#define SIMDJSON_SUPPORTS_DESERIALIZATION 0
+#endif
 #endif // SIMDJSON_COMPILER_CHECK_H
 /* end file simdjson/compiler_check.h */
 /* including simdjson/portability.h: #include "simdjson/portability.h" */
@@ -332,8 +344,6 @@ double from_chars(const char *first, const char* end) noexcept;
 #define SIMDJSON_ISALIGNED_N(ptr, n) (((uintptr_t)(ptr) & ((n)-1)) == 0)

 #if SIMDJSON_REGULAR_VISUAL_STUDIO
-  // We could use [[deprecated]] but it requires C++14
-  #define simdjson_deprecated __declspec(deprecated)

  #define simdjson_really_inline __forceinline
  #define simdjson_never_inline __declspec(noinline)
@@ -372,8 +382,6 @@ double from_chars(const char *first, const char* end) noexcept;
  #define SIMDJSON_POP_DISABLE_UNUSED_WARNINGS

 #else // SIMDJSON_REGULAR_VISUAL_STUDIO
-  // We could use [[deprecated]] but it requires C++14
-  #define simdjson_deprecated __attribute__((deprecated))

  #define simdjson_really_inline inline __attribute__((always_inline))
  #define simdjson_never_inline inline __attribute__((noinline))
@@ -2662,6 +2670,122 @@ inline const std::string error_message(int error) noexcept;
 #endif // SIMDJSON_ERROR_H
 /* end file simdjson/error.h */
 /* skipped duplicate #include "simdjson/portability.h" */
+/* including simdjson/concepts.h: #include "simdjson/concepts.h" */
+/* begin file simdjson/concepts.h */
+#ifndef SIMDJSON_CONCEPTS_H
+#define SIMDJSON_CONCEPTS_H
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+
+#include <concepts>
+#include <type_traits>
+
+namespace simdjson {
+namespace concepts {
+
+namespace details {
+#define SIMDJSON_IMPL_CONCEPT(name, method)                                    \
+  template <typename T>                                                        \
+  concept supports_##name = !std::is_const_v<T> && requires {                  \
+    typename std::remove_cvref_t<T>::value_type;                               \
+    requires requires(typename std::remove_cvref_t<T>::value_type &&val,       \
+                      T obj) {                                                 \
+      obj.method(std::move(val));                                              \
+      requires !requires { obj = std::move(val); };                            \
+    };                                                                         \
+  };
+
+SIMDJSON_IMPL_CONCEPT(emplace_back, emplace_back);
+SIMDJSON_IMPL_CONCEPT(emplace, emplace);
+SIMDJSON_IMPL_CONCEPT(push_back, push_back);
+SIMDJSON_IMPL_CONCEPT(add, add);
+SIMDJSON_IMPL_CONCEPT(push, push);
+SIMDJSON_IMPL_CONCEPT(append, append);
+SIMDJSON_IMPL_CONCEPT(insert, insert);
+SIMDJSON_IMPL_CONCEPT(op_append, operator+=);
+
+#undef SIMDJSON_IMPL_CONCEPT
+} // namespace details
+
+/// Check if T is a container that we can append to, including:
+///   std::vector, std::deque, std::list, std::string, ...
+template <typename T>
+concept appendable_containers =
+    details::supports_emplace_back<T> || details::supports_emplace<T> ||
+    details::supports_push_back<T> || details::supports_push<T> ||
+    details::supports_add<T> || details::supports_append<T> ||
+    details::supports_insert<T>;
+
+/// Insert into the container however possible
+template <appendable_containers T, typename... Args>
+constexpr decltype(auto) emplace_one(T &vec, Args &&...args) {
+  if constexpr (details::supports_emplace_back<T>) {
+    return vec.emplace_back(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_emplace<T>) {
+    return vec.emplace(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_push_back<T>) {
+    return vec.push_back(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_push<T>) {
+    return vec.push(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_add<T>) {
+    return vec.add(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_append<T>) {
+    return vec.append(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_insert<T>) {
+    return vec.insert(std::forward<Args>(args)...);
+  } else if constexpr (details::supports_op_append<T> && sizeof...(Args) == 1) {
+    return vec.operator+=(std::forward<Args>(args)...);
+  } else {
+    static_assert(!sizeof(T *),
+                  "We don't know how to add things to this container");
+  }
+}
+
+/// This checks if the container will return a reference to the newly added
+/// element after an insert which for example `std::vector::emplace_back` does
+/// since C++17; this will allow some optimizations.
+template <typename T>
+concept returns_reference = appendable_containers<T> && requires {
+  typename std::remove_cvref_t<T>::reference;
+  requires requires(typename std::remove_cvref_t<T>::value_type &&val, T obj) {
+    {
+      emplace_one(obj, std::move(val))
+    } -> std::same_as<typename std::remove_cvref_t<T>::reference>;
+  };
+};
+
+template <typename T>
+concept smart_pointer = requires(std::remove_cvref_t<T> ptr) {
+  // Check if T has a member type named element_type
+  typename std::remove_cvref_t<T>::element_type;
+
+  // Check if T has a get() member function
+  {
+    ptr.get()
+  } -> std::same_as<typename std::remove_cvref_t<T>::element_type *>;
+
+  // Check if T can be dereferenced
+  { *ptr } -> std::same_as<typename std::remove_cvref_t<T>::element_type &>;
+};
+
+template <typename T>
+concept optional_type = requires(std::remove_cvref_t<T> obj) {
+  typename std::remove_cvref_t<T>::value_type;
+  { 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
+};
+
+} // namespace concepts
+} // namespace simdjson
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+#endif // SIMDJSON_CONCEPTS_H
+/* end file simdjson/concepts.h */

 /**
 * @brief The top level simdjson namespace, containing everything the library provides.
@@ -6447,7 +6571,6 @@ extern SIMDJSON_DLLIMPORTEXPORT const uint64_t thintable_epi8[256];

 #endif // SIMDJSON_INTERNAL_SIMDPRUNE_TABLES_H
 /* end file simdjson/internal/simdprune_tables.h */
-
 #endif // SIMDJSON_GENERIC_DEPENDENCIES_H
 /* end file simdjson/generic/dependencies.h */
 /* including generic/dependencies.h: #include <generic/dependencies.h> */
@@ -2,33 +2,37 @@
 link_libraries(simdjson)
 include_directories(..)
 add_subdirectory(compilation_failure_tests)
-add_cpp_test(ondemand_log_tests              LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_log_error_tests        LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_tostring_tests         LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_active_tests           LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_array_tests            LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_array_error_tests      LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_compilation_tests      LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_document_stream_tests  LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_error_tests            LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_error_location_tests   LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_json_pointer_tests     LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_json_path_tests        LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_key_string_tests       LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_misc_tests             LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_number_tests           LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_number_in_string_tests LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_object_tests           LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_object_error_tests     LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_ordering_tests         LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_parse_api_tests        LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_readme_examples        LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_scalar_tests           LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_to_string              LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_twitter_tests          LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_wrong_type_error_tests LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_iterate_many_csv       LABELS ondemand acceptance per_implementation)
-add_cpp_test(ondemand_extract_tests          LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_car_tag_invoke_deserialization LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_car_deserialization            LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_log_tests                      LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_log_error_tests                LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_tostring_tests                 LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_active_tests                   LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_array_tests                    LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_array_error_tests              LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_compilation_tests              LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_document_stream_tests          LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_error_tests                    LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_error_location_tests           LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_json_pointer_tests             LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_json_path_tests                LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_key_string_tests               LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_misc_tests                     LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_number_tests                   LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_number_in_string_tests         LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_object_tests                   LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_object_error_tests             LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_ordering_tests                 LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_parse_api_tests                LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_readme_examples                LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_scalar_tests                   LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_to_string                      LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_twitter_tests                  LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_wrong_type_error_tests         LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_iterate_many_csv               LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_custom_types_tests             LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_custom_types_document_tests    LABELS ondemand acceptance per_implementation)
+add_cpp_test(ondemand_stl_types_tests                LABELS ondemand acceptance per_implementation)
 if(NOT SIMDJSON_SANITIZE)
  add_cpp_test(ondemand_cacheline              LABELS ondemand acceptance per_implementation)
 endif()
@@ -13,8 +13,7 @@ function(add_dual_compile_test TEST_NAME)
  target_compile_definitions(${TEST_NAME}_should_not_compile PRIVATE COMPILATION_TEST_USE_FAILING_CODE=1)
 endfunction(add_dual_compile_test)

-add_dual_compile_test(iterate_object)
-add_dual_compile_test(iterate_array)
+
 add_dual_compile_test(iterate_char_star)
 add_dual_compile_test(iterate_string_view)
 add_dual_compile_test(iterate_temporary_buffer)
@@ -1,34 +0,0 @@
-
-#include <iostream>
-#include "simdjson.h"
-
-using namespace simdjson;
-
-int main() {
-    auto json = "[1]"_padded;
-    ondemand::parser parser;
-    auto f = [](ondemand::parser& p, simdjson::padded_string& jsons) -> ondemand::document {
-        ondemand::document doc;
-        auto error = p.iterate(jsons).get(doc);
-        if(error) { std::abort(); }
-        return doc;
-    };
-    ondemand::array arrayv;
-#if COMPILATION_TEST_USE_FAILING_CODE
-    // Not allowed as this would be unsafe, the document must remain alive.
-    auto error = f(parser).get_array().get(arrayv);
-#else
-    ondemand::document doc = f(parser, json);
-    auto error = doc.get_array().get(arrayv);
-#endif
-    if(error) {
-        std::cout << "Failure" << std::endl;
-    }
-    int64_t a = 0;
-    error = arrayv.at(0).get_int64().get(a);
-    if(error) {
-        std::cout << "failure" << std::endl;
-    }
-    printf("a = %d\n", (int)a);
-    return EXIT_SUCCESS;
-}
@@ -1,34 +0,0 @@
-
-#include <iostream>
-#include "simdjson.h"
-
-using namespace simdjson;
-
-int main() {
-    auto json = "{\"a\":1}"_padded;
-    ondemand::parser parser;
-    auto f = [](ondemand::parser& p, simdjson::padded_string& jsons) -> ondemand::document {
-        ondemand::document doc;
-        auto error = p.iterate(jsons).get(doc);
-        if(error) { std::abort(); }
-        return doc;
-    };
-    ondemand::object objv;
-#if COMPILATION_TEST_USE_FAILING_CODE
-    // Not allowed as this would be unsafe, the document must remain alive.
-    auto error = f(parser).get_object().get(objv);
-#else
-    ondemand::document doc = f(parser, json);
-    auto error = doc.get_object().get(objv);
-#endif
-    if(error) {
-        std::cout << "Failure" << std::endl;
-    }
-    int64_t a = 0;
-    error = objv["a"].get_int64().get(a);
-    if(error) {
-        std::cout << "failure" << std::endl;
-    }
-    printf("a = %d\n", (int)a);
-    return EXIT_SUCCESS;
-}
@@ -0,0 +1,263 @@
+#include "simdjson.h"
+#include "test_ondemand.h"
+#include <iostream>
+#include <vector>
+
+using namespace simdjson;
+
+/**
+ * A custom type that we want to parse.
+ */
+struct Car {
+  std::string make{};
+  std::string model{};
+  int64_t year{};
+  std::vector<double> tire_pressure{};
+  bool operator==(const Car &other) const {
+    return make == other.make && model == other.model && year == other.year &&
+           tire_pressure == other.tire_pressure;
+  }
+};
+
+std::ostream &operator<<(std::ostream &os, const Car &c) {
+  os << c.make << " " << c.model << " " << c.year << " ";
+  for (auto p : c.tire_pressure) {
+    os << p << " ";
+  }
+  return os;
+}
+
+#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+// This code is not necessary if you have a C++20 compliant system:
+template <>
+simdjson_inline simdjson_result<std::vector<double>>
+simdjson::ondemand::value::get() noexcept {
+  ondemand::array array;
+  auto error = get_array().get(array);
+  if (error) {
+    return error;
+  }
+  std::vector<double> vec;
+  for (auto v : array) {
+    double val;
+    error = v.get_double().get(val);
+    if (error) {
+      return error;
+    }
+    vec.push_back(val);
+  }
+  return vec;
+}
+#endif
+
+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;
+  }
+  if ((error = obj["tire_pressure"].get<std::vector<double>>().get(
+           car.tire_pressure))) {
+    return error;
+  }
+  return car;
+}
+
+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;
+  }
+  if ((error = obj["tire_pressure"].get<std::vector<double>>().get(
+           car.tire_pressure))) {
+    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;
+  }
+  if ((error = obj["tire_pressure"].get<std::vector<double>>().get(
+           car.tire_pressure))) {
+    return error;
+  }
+  return car;
+}
+
+int main_should_compile(void) {
+  padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+  for (auto val : doc) {
+#if SIMDJSON_EXCEPTIONS
+    Car c(val); // an exception may be thrown
+#else
+    Car c;
+    if (auto error = val.get<Car>().get(c)) {
+      std::cerr << error << std::endl;
+      return EXIT_FAILURE;
+    }
+#endif
+  }
+  return EXIT_SUCCESS;
+}
+
+namespace car_error_tests {
+bool car_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+  std::vector<Car> cars;
+  for (auto val : doc) {
+#if SIMDJSON_EXCEPTIONS
+    Car c(val); // an exception may be thrown
+#else
+    Car c;
+    if (auto error = val.get<Car>().get(c)) {
+      std::cerr << error << std::endl;
+      return EXIT_FAILURE;
+    }
+#endif
+    cars.push_back(c);
+    std::cout << c.make << std::endl;
+  }
+  std::vector<Car> expected = {{"Toyota", "Camry", 2018, {40.1, 39.9}},
+                               {"Kia", "Soul", 2012, {30.1, 31.0}},
+                               {"Toyota", "Tercel", 1999, {29.8, 30.0}}};
+  ASSERT_EQUAL(cars.size(), expected.size());
+  for (size_t i = 0; i < cars.size(); i++) {
+    ASSERT_EQUAL(cars[i], expected[i]);
+  }
+  TEST_SUCCEED();
+}
+
+bool car_doc_deserialize() {
+  TEST_START();
+  padded_string json = R"(  { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+)"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+#if SIMDJSON_EXCEPTIONS
+  Car c(doc);   // an exception may be thrown
+#else
+  Car c;
+  if (auto error = doc.get<Car>().get(c)) {
+    std::cerr << error << std::endl;
+    return EXIT_FAILURE;
+  }
+#endif
+  Car expected = {"Toyota", "Camry", 2018, {40.1, 39.9}};
+  ASSERT_EQUAL(c, expected);
+  TEST_SUCCEED();
+}
+
+bool car_stream_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] }
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+)"_padded;
+  ondemand::parser parser;
+  ondemand::document_stream stream;
+  auto error = parser.iterate_many(json).get(stream);
+  if(error) {
+    std::cerr << error << std::endl;
+    return EXIT_FAILURE;
+  }
+  std::vector<Car> cars;
+
+#if SIMDJSON_EXCEPTIONS
+  for(ondemand::document_reference doc : stream) {
+    //Car c(doc);   // an exception may be thrown
+    cars.push_back(Car(doc)); // an exception may be thrown
+  }
+#else
+  for(auto doc : stream) {
+    Car c;
+    if ((error = doc.get<Car>().get(c))) {
+      std::cerr << error << std::endl;
+      return EXIT_FAILURE;
+    }
+    cars.push_back(c);
+  }
+#endif
+  std::vector<Car> expected = {{"Toyota", "Camry", 2018, {40.1, 39.9}},
+                               {"Kia", "Soul", 2012, {30.1, 31.0}},
+                               {"Toyota", "Tercel", 1999, {29.8, 30.0}}};
+  ASSERT_EQUAL(cars.size(), expected.size());
+  for (size_t i = 0; i < cars.size(); i++) {
+    ASSERT_EQUAL(cars[i], expected[i]);
+  }
+  TEST_SUCCEED();
+}
+
+bool run() { return car_stream_deserialize() && car_doc_deserialize() && car_deserialize(); }
+} // namespace car_error_tests
+
+int main(int argc, char *argv[]) {
+  return test_main(argc, argv, car_error_tests::run);
+}
@@ -0,0 +1,335 @@
+#include "simdjson.h"
+#include "test_ondemand.h"
+#include <cstdlib>
+#include <iostream>
+#include <vector>
+#include <list>
+#include <optional>
+
+using namespace simdjson;
+
+#if !SIMDJSON_SUPPORTS_DESERIALIZATION
+
+int main(void) {
+  printf("This test is only relevant when SIMDJSON_SUPPORTS_DESERIALIZATION is true (C++20)\n");
+  return EXIT_SUCCESS;
+}
+#else
+
+/**
+ * A custom type that we want to parse.
+ */
+struct Car {
+  std::string make{};
+  std::string model{};
+  int year{};
+  std::vector<float> tire_pressure{};
+  bool operator==(const Car &other) const {
+    return make == other.make && model == other.model && year == other.year &&
+           tire_pressure == other.tire_pressure;
+  }
+};
+
+std::ostream &operator<<(std::ostream &os, const Car &c) {
+  os << c.make << " " << c.model << " " << c.year << " ";
+  for (auto p : c.tire_pressure) {
+    os << p << " ";
+  }
+  return os;
+}
+
+
+
+namespace simdjson {
+// This tag_invoke MUST be inside simdjson namespace
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, Car& car) {
+  ondemand::object obj;
+  auto error = val.get_object().get(obj);
+  if (error) {
+    return error;
+  }
+  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(car.year))) {
+    return error;
+  }
+  if ((error = obj["tire_pressure"].get<std::vector<float>>().get(
+           car.tire_pressure))) {
+    return error;
+  }
+  return simdjson::SUCCESS;
+}
+
+// suppose we want to filter out all Toyotas
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, std::list<Car>& car) {
+  ondemand::array arr;
+  auto error = val.get_array().get(arr);
+  if (error) {
+    return error;
+  }
+  for (auto v : arr) {
+    Car c;
+    if ((error = v.get<Car>().get(c))) {
+      return error;
+    }
+    if(c.make != "Toyota") {
+      car.push_back(c);
+    }
+  }
+  return simdjson::SUCCESS;
+}
+} // namespace simdjson
+
+
+int main_should_compile(void) {
+  padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+  for (auto val : doc) {
+#if SIMDJSON_EXCEPTIONS
+    Car c(val); // an exception may be thrown
+#else
+    Car c;
+    if (auto error = val.get<Car>().get(c)) {
+      std::cerr << error << std::endl;
+      return EXIT_FAILURE;
+    }
+#endif
+  }
+  return EXIT_SUCCESS;
+}
+
+namespace car_error_tests {
+bool car_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+  std::vector<Car> cars;
+  for (auto val : doc) {
+#if SIMDJSON_EXCEPTIONS
+    Car c(val); // an exception may be thrown
+#else
+    Car c;
+    if (auto error = val.get<Car>().get(c)) {
+      std::cerr << error << std::endl;
+      return EXIT_FAILURE;
+    }
+#endif
+    cars.push_back(c);
+    std::cout << c.make << std::endl;
+  }
+  std::vector<Car> expected = {{"Toyota", "Camry", 2018, {40.1f, 39.9f}},
+                               {"Kia", "Soul", 2012, {30.1f, 31.0f}},
+                               {"Toyota", "Tercel", 1999, {29.8f, 30.0f}}};
+  ASSERT_EQUAL(cars.size(), expected.size());
+  for (size_t i = 0; i < cars.size(); i++) {
+    ASSERT_EQUAL(cars[i], expected[i]);
+  }
+  TEST_SUCCEED();
+}
+
+bool vector_car_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+#if SIMDJSON_EXCEPTIONS
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
+  std::vector<Car> cars = doc.get<std::vector<Car>>();  // an exception may be thrown
+#else
+  std::vector<Car> cars(doc); // an exception may be thrown
+#endif
+#else
+  std::vector<Car> cars;
+  if (auto error = doc.get<std::vector<Car>>().get(cars)) {
+    std::cerr << error << std::endl;
+    return EXIT_FAILURE;
+  }
+#endif
+  std::vector<Car> expected = {{"Toyota", "Camry", 2018, {40.1f, 39.9f}},
+                               {"Kia", "Soul", 2012, {30.1f, 31.0f}},
+                               {"Toyota", "Tercel", 1999, {29.8f, 30.0f}}};
+  ASSERT_EQUAL(cars.size(), expected.size());
+  for (size_t i = 0; i < cars.size(); i++) {
+    ASSERT_EQUAL(cars[i], expected[i]);
+  }
+  TEST_SUCCEED();
+}
+
+
+bool list_car_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+#if SIMDJSON_EXCEPTIONS
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
+  std::list<Car> cars = doc.get<std::list<Car>>();  // an exception may be thrown
+#else
+  std::list<Car> cars(doc); // an exception may be thrown
+#endif
+#else
+  std::list<Car> cars;
+  if (auto error = doc.get<std::list<Car>>().get(cars)) {
+    std::cerr << error << std::endl;
+    return EXIT_FAILURE;
+  }
+#endif
+  std::list<Car> expected = {{"Kia", "Soul", 2012, {30.1f, 31.0f}}};
+  ASSERT_EQUAL(cars.size(), expected.size());
+  ASSERT_EQUAL(cars.front(), expected.front());
+  TEST_SUCCEED();
+}
+
+bool optional_car_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( { "car1": { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+})"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto error = parser.iterate(json).get(doc);
+  std::optional<Car> car;
+  error = doc["key not found"].get<std::optional<Car>>().get(car);
+  ASSERT_TRUE(!car);
+  error = doc["car1"].get<std::optional<Car>>().get(car);
+  std::optional<Car> expected = Car{"Toyota", "Camry", 2018, {40.1f, 39.9f}};
+  ASSERT_TRUE(car == expected);
+  TEST_SUCCEED();
+}
+
+bool car_doc_deserialize() {
+  TEST_START();
+  padded_string json = R"(  { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+)"_padded;
+  ondemand::parser parser;
+  ondemand::document doc;
+  [[maybe_unused]] auto doc_error = parser.iterate(json).get(doc);
+#if SIMDJSON_EXCEPTIONS
+  Car c(doc);   // an exception may be thrown
+#else
+  Car c;
+  if (auto error = doc.get<Car>().get(c)) {
+    std::cerr << error << std::endl;
+    return EXIT_FAILURE;
+  }
+#endif
+  Car expected = {"Toyota", "Camry", 2018, {40.1f, 39.9f}};
+  ASSERT_EQUAL(c, expected);
+  TEST_SUCCEED();
+}
+
+
+bool car_stream_deserialize() {
+  TEST_START();
+  padded_string json =
+      R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] }
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] }
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+)"_padded;
+  ondemand::parser parser;
+  ondemand::document_stream stream;
+  [[maybe_unused]] auto error = parser.iterate_many(json).get(stream);
+  std::vector<Car> cars;
+
+#if SIMDJSON_EXCEPTIONS
+  for(auto doc : stream) {
+    cars.push_back((Car)doc); // an exception may be thrown
+  }
+#else
+  for(auto doc : stream) {
+    Car c;
+    if ((error = doc.get<Car>().get(c))) {
+      std::cerr << error << std::endl;
+      return EXIT_FAILURE;
+    }
+    cars.push_back(c);
+  }
+#endif
+  std::vector<Car> expected = {{"Toyota", "Camry", 2018, {40.1f, 39.9f}},
+                               {"Kia", "Soul", 2012, {30.1f, 31.0f}},
+                               {"Toyota", "Tercel", 1999, {29.8f, 30.0f}}};
+  ASSERT_EQUAL(cars.size(), expected.size());
+  for (size_t i = 0; i < cars.size(); i++) {
+    ASSERT_EQUAL(cars[i], expected[i]);
+  }
+  TEST_SUCCEED();
+}
+
+bool car_unique_ptr_deserialize() {
+  TEST_START();
+  auto const json = R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc;
+  [[maybe_unused]] auto error = parser.iterate(json).get(doc);
+#if SIMDJSON_EXCEPTIONS
+  std::unique_ptr<Car> c(doc);
+#else
+  std::unique_ptr<Car> c;
+  if ((error = doc.get<std::unique_ptr<Car>>().get(c))) {
+    std::cerr << error << std::endl;
+    return EXIT_FAILURE;
+  }
+#endif
+  ASSERT_EQUAL(c->make, "Toyota");
+  TEST_SUCCEED();
+}
+
+bool run() { return list_car_deserialize()
+                    && optional_car_deserialize()
+                    && car_unique_ptr_deserialize()
+                    && vector_car_deserialize()
+                    && car_stream_deserialize()
+                    && car_doc_deserialize()
+                    && car_deserialize(); }
+} // namespace car_error_tests
+
+int main(int argc, char *argv[]) {
+  return test_main(argc, argv, car_error_tests::run);
+}
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
@@ -59,22 +59,6 @@ void compilation_test_3() {
    }
  }
 }
-
-// Do not run this, it is only meant to compile
-void compilation_test_4() {
-  const padded_string bogus = ""_padded;
-  ondemand::parser parser;
-  int64_t x1 = (int64_t)parser.iterate(bogus);
-  double x2 = (double)parser.iterate(bogus);
-  std::string_view x = (std::string_view)parser.iterate(bogus);
-  uint64_t x3 = (uint64_t)parser.iterate(bogus);
-  bool x4 = (bool)parser.iterate(bogus);
-  (void) x1;
-  (void) x2;
-  (void) x3;
-  (void) x4;
-  (void) x;
-}
 #endif // SIMDJSON_EXCEPTIONS

 int main(void) {
@@ -0,0 +1,178 @@
+#include "simdjson.h"
+#include "test_ondemand.h"
+
+#include <string>
+#include <vector>
+
+
+namespace doc_custom_types_tests {
+#if SIMDJSON_EXCEPTIONS && defined(__cpp_concepts)
+struct Car {
+  std::string make{};
+  std::string model{};
+  int64_t year{};
+  std::vector<double> tire_pressure{};
+
+  friend error_code tag_invoke(simdjson::deserialize_tag,
+                                         auto &val, Car& car) {
+    simdjson::ondemand::object obj;
+    if (auto const error = val.get_object().get(obj)) {
+      return error;
+    }
+    // Instead of repeatedly obj["something"], we iterate through the object
+    // which we expect to be faster.
+    for (auto field : obj) {
+      simdjson::ondemand::raw_json_string key;
+      if (auto const error = field.key().get(key)) {
+        return error;
+      }
+      if (key == "make") {
+        if (auto const error = field.value().get_string(car.make)) {
+          return error;
+        }
+      } else if (key == "model") {
+        if (auto const error = field.value().get_string(car.model)) {
+          return error;
+        }
+      } else if (key == "year") {
+        if (auto const error = field.value().get_int64().get(car.year)) {
+          return error;
+        }
+      } else if (key == "tire_pressure") {
+        if (auto const error = field.value().get<std::vector<double>>().get(
+                car.tire_pressure)) {
+          return error;
+        }
+      }
+    }
+    return error_code::SUCCESS;
+  }
+};
+
+static_assert(simdjson::custom_deserializable<std::unique_ptr<Car>, simdjson::ondemand::value>, "It should be invocable");
+static_assert(simdjson::custom_deserializable<std::unique_ptr<Car>, simdjson::ondemand::document>, "Tag_invoke should work with document as well.");
+static_assert(simdjson::custom_deserializable<std::vector<Car>, simdjson::ondemand::value>, "It should be invocable");
+static_assert(simdjson::custom_deserializable<std::vector<Car>, simdjson::ondemand::document>, "Tag_invoke should work with document as well.");
+
+bool custom_test() {
+  TEST_START();
+  auto const json = R"( {
+      "make": "Toyota",
+      "model": "Camry",
+      "year": 2018,
+      "tire_pressure": [ 40.1, 39.9 ]
+ } )"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+
+  // creating car directly from "doc":
+  const std::unique_ptr<Car> car(doc);
+  if (car->make != "Toyota") {
+    return false;
+  }
+  if (car->model != "Camry") {
+    return false;
+  }
+  if (car->year != 2018) {
+    return false;
+  }
+  if (car->tire_pressure.size() != 2) {
+    return false;
+  }
+  TEST_SUCCEED();
+}
+
+bool readme_test() {
+  TEST_START();
+  auto const json = R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  std::unique_ptr<Car> c(doc);
+  std::cout << c->make << std::endl;
+  TEST_SUCCEED();
+}
+
+
+bool simple_document_test() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  Car c(doc);
+  std::cout << c.make << std::endl;
+  ASSERT_EQUAL(c.make, "Toyota");
+  TEST_SUCCEED();
+}
+
+bool custom_test_crazier() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
+  std::vector<Car> cars = doc.get<std::vector<Car>>();
+#else
+  std::vector<Car> cars(doc);
+#endif
+  for(Car& c : cars) {
+    std::cout << c.year << std::endl;
+    if (c.make != "Toyota" && c.make != "Kia") {
+      return false;
+    }
+    if (c.model != "Camry" && c.model != "Soul" && c.model != "Tercel") {
+      return false;
+    }
+    if (c.year != 2018 && c.year != 2012 && c.year != 1999) {
+      return false;
+    }
+    if (c.tire_pressure.size() != 2) {
+      return false;
+    }
+  }
+  TEST_SUCCEED();
+}
+
+bool simple_document_test_no_except() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] })"_padded;
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  Car c;
+  auto error = doc.get(c);
+  if(error) { std::cerr << simdjson::error_message(error); return false; }
+  std::cout << c.make << std::endl;
+  ASSERT_EQUAL(c.make, "Toyota");
+  TEST_SUCCEED();
+}
+#endif // SIMDJSON_EXCEPTIONS
+bool run() {
+  return
+#if SIMDJSON_EXCEPTIONS && defined(__cpp_concepts)
+      readme_test() &&
+      custom_test() &&
+      simple_document_test() &&
+      simple_document_test_no_except() &&
+      custom_test_crazier() &&
+#endif // SIMDJSON_EXCEPTIONS
+      true;
+}
+
+} // namespace doc_custom_types_tests
+
+int main(const int argc, char *argv[]) {
+  return test_main(argc, argv, doc_custom_types_tests::run);
+}
@@ -0,0 +1,195 @@
+#include "simdjson.h"
+#include "test_ondemand.h"
+
+#include <string>
+#include <vector>
+
+
+namespace custom_types_tests {
+#if SIMDJSON_EXCEPTIONS && SIMDJSON_SUPPORTS_DESERIALIZATION
+struct Car {
+  std::string make{};
+  std::string model{};
+  int year{};
+  std::vector<double> tire_pressure{};
+
+  friend simdjson::error_code tag_invoke(simdjson::deserialize_tag, auto &val, Car& car) {
+    simdjson::ondemand::object obj;
+    auto error = val.get_object().get(obj);
+    if (error) {
+      return error;
+    }
+    // Instead of repeatedly obj["something"], we iterate through the object
+    // which we expect to be faster.
+    for (auto field : obj) {
+      simdjson::ondemand::raw_json_string key;
+      error = field.key().get(key);
+      if (error) {
+        return error;
+      }
+      if (key == "make") {
+        error = field.value().get_string(car.make);
+        if (error) {
+          return error;
+        }
+      } else if (key == "model") {
+        error = field.value().get_string(car.model);
+        if (error) {
+          return error;
+        }
+      } else if (key == "year") {
+        error = field.value().get(car.year);
+        if (error) {
+          return error;
+        }
+      } else if (key == "tire_pressure") {
+        error = field.value().get(car.tire_pressure);
+        if (error) {
+          return error;
+        }
+      }
+    }
+    return simdjson::SUCCESS;
+  }
+};
+
+static_assert(simdjson::custom_deserializable<std::unique_ptr<Car>>, "It should be deserializable");
+
+bool custom_uniqueptr_test() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  for (auto val : doc) {
+    std::unique_ptr<Car> c(val);
+    if (c->make != "Toyota" && c->make != "Kia") {
+      return false;
+    }
+    if (c->model != "Camry" && c->model != "Soul" && c->model != "Tercel") {
+      return false;
+    }
+    if (c->year != 2018 && c->year != 2012 && c->year != 1999) {
+      return false;
+    }
+    if (c->tire_pressure.size() != 2) {
+      return false;
+    }
+  }
+
+  TEST_SUCCEED();
+}
+
+
+
+bool custom_test() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  for (auto val : doc) {
+    Car c(val);
+    if (c.make != "Toyota" && c.make != "Kia") {
+      return false;
+    }
+    if (c.model != "Camry" && c.model != "Soul" && c.model != "Tercel") {
+      return false;
+    }
+    if (c.year != 2018 && c.year != 2012 && c.year != 1999) {
+      return false;
+    }
+    if (c.tire_pressure.size() != 2) {
+      return false;
+    }
+  }
+
+  TEST_SUCCEED();
+}
+
+
+
+bool custom_test_crazy() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  for (auto val : doc) {
+    Car c(val);
+    std::cout << c.year << std::endl;
+    if (c.make != "Toyota" && c.make != "Kia") {
+      return false;
+    }
+    if (c.model != "Camry" && c.model != "Soul" && c.model != "Tercel") {
+      return false;
+    }
+    if (c.year != 2018 && c.year != 2012 && c.year != 1999) {
+      return false;
+    }
+    if (c.tire_pressure.size() != 2) {
+      return false;
+    }
+  }
+
+  TEST_SUCCEED();
+}
+
+bool custom_no_except() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
+       "tire_pressure": [ 40.1, 39.9 ] },
+  { "make": "Kia",    "model": "Soul",   "year": 2012,
+       "tire_pressure": [ 30.1, 31.0 ] },
+  { "make": "Toyota", "model": "Tercel", "year": 1999,
+       "tire_pressure": [ 29.8, 30.0 ] }
+])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  for (auto val : doc) {
+    Car c;
+    auto error = val.get(c);
+    if(error) { std::cerr << simdjson::error_message(error) << std::endl; return false; }
+  }
+
+  TEST_SUCCEED();
+}
+#endif // SIMDJSON_EXCEPTIONS
+bool run() {
+  return
+#if SIMDJSON_EXCEPTIONS && SIMDJSON_SUPPORTS_DESERIALIZATION
+      custom_test() &&
+      custom_uniqueptr_test() &&
+      custom_no_except() &&
+#endif // SIMDJSON_EXCEPTIONS
+      true;
+}
+
+} // namespace custom_types_tests
+
+int main(int argc, char *argv[]) {
+  return test_main(argc, argv, custom_types_tests::run);
+}
@@ -1,116 +0,0 @@
-#include "simdjson.h"
-#include "test_ondemand.h"
-
-using namespace simdjson;
-
-namespace multi_get_tests {
-#ifdef __cpp_concepts
-struct Car {
-  std::string_view make;
-  std::string_view model;
-  std::int64_t year = 0;
-  struct wheel_size_type {
-    std::int64_t front = 0;
-    std::int64_t back = 0;
-  } wheels;
-
-  static simdjson_result<Car> create(auto& value) {
-    using ondemand::to;
-    using ondemand::sub;
-
-    simdjson::ondemand::object obj;
-    auto error = value.get_object().get(obj);
-    if (error) {
-      return error;
-    }
-    Car car{};
-    // Instead of this:
-    //     for (auto field : obj) {
-    //       simdjson::ondemand::raw_json_string key;
-    //       error = field.key().get(key);
-    //       if (error) {
-    //         return error;
-    //       }
-    //       if (key == "make") {
-    //         error = field.value().get_string(car.make);
-    //         if (error) {
-    //           return error;
-    //         }
-    //       } else if (key == "model") {
-    //         error = field.value().get_string(car.model);
-    //         if (error) {
-    //           return error;
-    //         }
-    //       } else if (key == "year") {
-    //         error = field.value().get(car.year);
-    //         if (error) {
-    //           return error;
-    //         }
-    //     }
-    //
-    // we can do this now:
-    error = obj.extract(
-      to{"wheels", sub{
-        to{"front", car.wheels.front},
-        to{"back", car.wheels.back},
-      }},
-      to{"make", car.make},
-      to{"model", car.model},
-      to{"year", [&car](auto val) {
-        car.year = val;
-      }});
-    if (error) {
-      return error;
-    }
-    return car;
-  }
-};
-
-bool car_example() {
-  TEST_START();
-  simdjson::padded_string json =
-      R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
-       "tire_pressure": [ 40.1, 39.9 ], "wheels": { "front": 10, "back": 10 } },
-  { "make": "Kia",    "model": "Soul",   "year": 2012,
-       "tire_pressure": [ 30.1, 31.0 ], "wheels": { "front": 10, "back": 10 } },
-  { "make": "Toyota", "model": "Tercel", "year": 1999,
-       "tire_pressure": [ 29.8, 30.0 ], "wheels": { "front": 10, "back": 10 } }
-])"_padded;
-
-  simdjson::ondemand::parser parser;
-  simdjson::ondemand::document doc = parser.iterate(json);
-  for (auto val : doc) {
-    auto car = Car::create(val);
-    ASSERT_EQUAL(car.error(), SUCCESS);
-    Car const c(car.value());
-    if (c.make != "Toyota" && c.make != "Kia") {
-      return false;
-    }
-    if (c.model != "Camry" && c.model != "Soul" && c.model != "Tercel") {
-      return false;
-    }
-    if (c.year != 2018 && c.year != 2012 && c.year != 1999) {
-      return false;
-    }
-    if (c.wheels.front != 10 || c.wheels.back != 10) {
-      return false;
-    }
-  }
-
-  TEST_SUCCEED();
-}
-
-#endif
-bool run() {
-  return
-#ifdef __cpp_concepts
-      car_example() &&
-#endif
-      true;
-}
-
-} // namespace multi_get_tests
-
-int main(int argc, char *argv[]) {
-  return test_main(argc, argv, multi_get_tests::run);
-}
@@ -164,7 +164,8 @@ namespace json_pointer_tests {
        ASSERT_TRUE(is_scalar);
        ASSERT_ERROR(doc.at_pointer("").get(val), simdjson::SCALAR_DOCUMENT_AS_VALUE);
        std::cout << "  checking true"<< std::endl;
-        ASSERT_SUCCESS(parser.iterate(true_json).is_scalar().get(is_scalar));
+        ASSERT_SUCCESS(parser.iterate(true_json).get(doc));
+        ASSERT_SUCCESS(doc.is_scalar().get(is_scalar));
        ASSERT_TRUE(is_scalar);
        ASSERT_ERROR(doc.at_pointer("").get(val), simdjson::SCALAR_DOCUMENT_AS_VALUE);
        std::cout << "  checking object"<< std::endl;
@@ -49,6 +49,7 @@ struct Car {
  std::vector<double> tire_pressure;
 };

+#ifndef __cpp_concepts
 template <>
 simdjson_inline simdjson_result<std::vector<double>>
 simdjson::ondemand::value::get() noexcept {
@@ -66,7 +67,7 @@ simdjson::ondemand::value::get() noexcept {
  }
  return vec;
 }
-
+#endif


 template <>
@@ -75,29 +76,13 @@ simdjson_inline simdjson_result<Car> simdjson::ondemand::value::get() noexcept {
  auto error = get_object().get(obj);
  if (error) { return error; }
  Car car;
-  // Instead of repeatedly obj["something"], we iterate through the object which
-  // we expect to be faster.
-  for (auto field : obj) {
-    raw_json_string key;
-    if (error = field.key().get(key); error) { return error; }
-    if (key == "make") {
-      error = field.value().get_string(car.make);
-      if(error) { return error; }
-    } else if (key == "model") {
-      error = field.value().get_string(car.model);
-      if(error) { return error; }
-    } else if (key == "year") {
-      error = field.value().get_int64().get(car.year);
-      if(error) { return error; }
-    } else if (key == "tire_pressure") {
-      error = field.value().get<std::vector<double>>().get(car.tire_pressure);
-      if (error) { return error; }
-    }
-  }
+  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; }
+  if((error = obj["tire_pressure"].get<std::vector<double>>().get(car.tire_pressure))) { return error; }
  return car;
 }

-
 int custom_type_without_exceptions() {
  padded_string json = R"( [ { "make": "Toyota", "model": "Camry",  "year": 2018,
       "tire_pressure": [ 40.1, 39.9 ] },
@@ -193,8 +178,8 @@ int custom_type_with_exceptions() {
 ])"_padded;
  ondemand::parser parser;
  ondemand::document doc = parser.iterate(json);
-  for (auto val : doc) {
-    Car c(val);
+  for (auto value : doc) {
+    Car c(value);
    std::cout << c.make << std::endl;
  }
  return 0;
@@ -0,0 +1,257 @@
+#include "simdjson.h"
+#include "test_ondemand.h"
+
+#include <string>
+#include <vector>
+#include <list>
+#include <set>
+#include <stack>
+#include <queue>
+#include <deque>
+#include <unordered_set>
+#include <optional>
+
+#if SIMDJSON_SUPPORTS_DESERIALIZATION
+class Array : public std::vector<float> {};
+static_assert(simdjson::concepts::appendable_containers<Array>, "Array must be appendable_containers");
+static_assert(!simdjson::require_custom_serialization<Array>);
+namespace simdjson {
+// This tag_invoke MUST be inside simdjson namespace
+template <typename simdjson_value>
+auto tag_invoke(deserialize_tag, simdjson_value &val, Array& out) {
+    simdjson::ondemand::array arr;
+    SIMDJSON_TRY(val.get_array().get(arr));
+    for (auto v : arr) {
+      float temp;
+      if (auto const err = v.get<float>().get(temp); err) {
+        return err;
+      }
+      out.push_back(temp);
+      out.push_back(temp); // adding it twice
+    }
+    return error_code::SUCCESS;
+}
+} // namespace simdjson
+
+// require_custom_serialization
+#endif // SIMDJSON_SUPPORTS_DESERIALIZATION
+
+namespace stl_types {
+#if SIMDJSON_EXCEPTIONS && SIMDJSON_SUPPORTS_DESERIALIZATION
+
+bool basic_general_madness() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "codes": [1,2,3,4,18,19] },
+            { "codes": [1,3,4,111,1111] } ])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  std::vector<uint16_t> codes;
+  for (auto val : doc) {
+    simdjson::ondemand::object obj;
+    SIMDJSON_TRY(val.get_object().get(obj));
+    obj["codes"].get(codes); // append to it
+  }
+
+  if (codes.size() != 11) {
+    return false;
+  }
+  if (codes[5] != 19 || codes[7] != 3 || codes[9] != 111) {
+    return false;
+  }
+
+  TEST_SUCCEED();
+}
+
+bool basic_general_madness_vector() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "codes": [1.2, 3.4, 5.6, 7.8, 9.0] },
+            { "codes": [2.2, 4.4, 6.6, 8.8, 10.0] } ])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  std::vector<float> codes;
+  for (auto val : doc) {
+    simdjson::ondemand::object obj;
+    SIMDJSON_TRY(val.get_object().get(obj));
+    obj["codes"].get(codes); // append to it
+  }
+
+  if (codes.size() != 10) {
+    return false;
+  }
+  if (codes[5] != 2.2f || codes[7] != 6.6f || codes[9] != 10.0f) {
+    return false;
+  }
+
+  TEST_SUCCEED();
+}
+
+bool basic_general_madness_list() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "codes": [1.2, 3.4, 5.6, 7.8, 9.0] },
+            { "codes": [2.2, 4.4, 6.6, 8.8, 10.0] } ])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  std::list<float> codes;
+  for (auto val : doc) {
+    simdjson::ondemand::object obj;
+    SIMDJSON_TRY(val.get_object().get(obj));
+    obj["codes"].get(codes); // append to it
+  }
+
+  if (codes.size() != 10) {
+    return false;
+  }
+  if (codes.back() != 10.0f || codes.front() != 1.2f) {
+    return false;
+  }
+
+  TEST_SUCCEED();
+}
+
+
+
+bool basic_general_madness_Array() {
+  TEST_START();
+  simdjson::padded_string json =
+      R"( [ { "codes": [1.2, 3.4, 5.6, 7.8, 9.0] },
+            { "codes": [2.2, 4.4, 6.6, 8.8, 10.0] } ])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  Array codes;
+  for (auto val : doc) {
+    simdjson::ondemand::object obj;
+    SIMDJSON_TRY(val.get_object().get(obj));
+    obj["codes"].get(codes); // append to it
+  }
+  ASSERT_EQUAL(codes.size(), 20);
+  TEST_SUCCEED();
+}
+
+
+template <template <typename...> typename Container, typename ValT = float>
+bool basic_general_madness_container() {
+  TYPED_TEST_START(Container<ValT>);
+
+  simdjson::padded_string json =
+      R"( [ { "codes": [1.0, 3.4, 5.6, 7.8, 9.0] },
+            { "codes": [2.2, 4.4, 6.6, 8.8, 10.0] } ])"_padded;
+
+  simdjson::ondemand::parser parser;
+  simdjson::ondemand::document doc = parser.iterate(json);
+  Container<ValT> codes;
+  for (auto val : doc) {
+    simdjson::ondemand::object obj;
+    SIMDJSON_TRY(val.get_object().get(obj));
+    obj["codes"].get(codes); // append to it
+  }
+
+  if (codes.size() != 10) {
+    return false;
+  }
+
+
+  if constexpr (requires {codes.front();}) {
+    if constexpr (requires {*codes.front();}) {
+      if (*codes.front() != 1.0) {
+        return false;
+      }
+    } else {
+      if (codes.front() != 1.0) {
+        return false;
+      }
+    }
+  }
+  if constexpr (requires {codes.back();} ) {
+    if constexpr (requires {*codes.back();}) {
+      if (*codes.back() != 10.0) {
+        return false;
+      }
+    } else {
+      if (codes.back() != 10.0) {
+        return false;
+      }
+    }
+  }
+
+  TEST_SUCCEED();
+}
+
+
+#endif // SIMDJSON_EXCEPTIONS
+bool run() {
+  return
+#if SIMDJSON_EXCEPTIONS && SIMDJSON_SUPPORTS_DESERIALIZATION
+      basic_general_madness() &&
+      basic_general_madness_vector() &&
+      basic_general_madness_list() &&
+      basic_general_madness_Array() &&
+      basic_general_madness_container<std::vector>() &&
+      basic_general_madness_container<std::list>() &&
+      basic_general_madness_container<std::set>() &&
+      basic_general_madness_container<std::stack>() &&
+      basic_general_madness_container<std::queue>() &&
+      basic_general_madness_container<std::deque>() &&
+      basic_general_madness_container<std::priority_queue>() &&
+      basic_general_madness_container<std::unordered_set>() &&
+      basic_general_madness_container<std::multiset>() &&
+      basic_general_madness_container<std::unordered_multiset>() &&
+        // double:
+      basic_general_madness_container<std::vector, double>() &&
+      basic_general_madness_container<std::list, double>() &&
+      basic_general_madness_container<std::set, double>() &&
+      basic_general_madness_container<std::stack, double>() &&
+      basic_general_madness_container<std::queue, double>() &&
+      basic_general_madness_container<std::deque, double>() &&
+      basic_general_madness_container<std::priority_queue, double>() &&
+      basic_general_madness_container<std::unordered_set, double>() &&
+      basic_general_madness_container<std::multiset, double>() &&
+      basic_general_madness_container<std::unordered_multiset, double>() &&
+        // unique_ptr<double>:
+      basic_general_madness_container<std::vector, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::list, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::set, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::stack, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::deque, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::queue, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::priority_queue, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::unordered_set, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::multiset, std::unique_ptr<double>>() &&
+      basic_general_madness_container<std::unordered_multiset, std::unique_ptr<double>>() &&
+        // shared_ptr<double>:
+      basic_general_madness_container<std::vector, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::list, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::set, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::stack, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::deque, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::queue, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::priority_queue, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::unordered_set, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::multiset, std::shared_ptr<double>>() &&
+      basic_general_madness_container<std::unordered_multiset, std::shared_ptr<double>>() &&
+        // optional<double>:
+      basic_general_madness_container<std::vector, std::optional<double>>() &&
+      basic_general_madness_container<std::list, std::optional<double>>() &&
+      basic_general_madness_container<std::set, std::optional<double>>() &&
+      basic_general_madness_container<std::stack, std::optional<double>>() &&
+      basic_general_madness_container<std::deque, std::optional<double>>() &&
+      basic_general_madness_container<std::queue, std::optional<double>>() &&
+      basic_general_madness_container<std::priority_queue, std::optional<double>>() &&
+      basic_general_madness_container<std::unordered_set, std::optional<double>>() &&
+      basic_general_madness_container<std::multiset, std::optional<double>>() &&
+      basic_general_madness_container<std::unordered_multiset, std::optional<double>>() &&
+#endif // SIMDJSON_EXCEPTIONS
+      true;
+}
+
+} // namespace stl_types
+
+int main(int argc, char *argv[]) {
+  return test_main(argc, argv, stl_types::run);
+}
@@ -110,6 +110,7 @@ simdjson_inline bool assert_iterate_error(T &arr, simdjson::error_code expected,
  return assert_equal( count, 1, operation );
 }
 #define TEST_START()                    do { std::cout << "> Running " << __func__ << " ..." << std::endl; } while(0);
+#define TYPED_TEST_START(T)             do { std::cout << "> Running " << __func__ << "<" << typeid(T).name() << "> ..." << std::endl; } while(0);
 #define SUBTEST(NAME, TEST)             do { std::cout << " - Subtest " << (NAME) << " ..." << std::endl; if (!(TEST)) { return false; } } while (0);
 #define ASSERT_EQUAL(ACTUAL, EXPECTED)  do { if (!::assert_equal  ((ACTUAL), (EXPECTED), #ACTUAL)) { return false; } } while (0);
 #define ASSERT_RESULT(ACTUAL, EXPECTED) do { if (!::assert_result ((ACTUAL), (EXPECTED), #ACTUAL)) { return false; } } while (0);
Author	SHA1	Message	Date
Daniel Lemire	b7b01fd788	More documentation regarding builder (#2270 ) * minor update * more improvment to our documentation (builder branch) * putting back missing functions	2024-10-04 01:47:13 -04:00
Daniel Lemire	2c07a242ea	General madness simpler, no simpler!!! (#2267 ) * Minimal tag_invokes for STL types * simpler madness * adding a comment * missing file * minor tweaks to style * fixing incorrect max/min usage * updating single * simplify * validating the idea * putting back the concept * moving the include * guarding * Cheap General Madness (#2268) * Some General Concepts and their deserializations * Resolving ambiguity * Add missing #include * C++20 custom deserializer: better documentation (#2269) * mostly a documentation update. * missing cpp * [no-ci] fix comment * various minor fixes --------- Co-authored-by: Daniel Lemire <dlemire@lemire.me> --------- Co-authored-by: M. Bahoosh <12122474+the-moisrex@users.noreply.github.com> Co-authored-by: Daniel Lemire <dlemire@lemire.me> Co-authored-by: M. Bahoosh <moisrex@gmail.com>	2024-10-02 09:50:06 -04:00
Daniel Lemire	a63c77a977	typo	2024-09-26 17:20:44 -04:00
Daniel Lemire	43219e50e0	update CI on the builder_development_branch (no code change) (#2262 )	2024-09-25 12:33:04 -04:00
M. Bahoosh	49b9860899	Making `tag_invoke` a "put" as opposed to a "get" (#2256 ) * fix: add tests related to issue 2227 (#2229) * fix: add tests related to issue 2227 * avoiding name clash * pedantic fix * deprecate rvalue get on document * selectively deprecating * Fix ndjson spec link (#2234) * fix ndjson spec link The link in the readme of parse_many links to a casino spam site * fix link * [no-ci] Update README.md * Make simdjson compile again * Enable SIMDJSON_SINGLEHEADER=OFF in VS Code With singleheader on, clangd can't find the right include files. * Add missing include directives to static build targets of simdjson. (#2240) * adding a warning * adding warning regarding SIMDJSON_BUILD_STATIC_LIB * release candidate * pedantic viable size * Making tag_invoke a feeder instead of a producer * adding missing undef silencer (#2253) * Ignore pragma once when amalgamating source files (#2248) With gcc it causes an error in `simdjson.cpp`: ``` simdjson.cpp:548:9: warning: #pragma once in main file 548 \| #pragma once \| ^~~~ ``` It had previously been commented out in: https://github.com/simdjson/simdjson/commit/6ef555e6fb79363fae057a9a46b52cd208d9e305 However, this was lost in an upgrade: https://github.com/simdjson/simdjson/commit/2a4ff7346813b120f2b5b40e95d69352b593cc9c * Update CI (#2254) * adding missing undef silencer * Updating CI * more fixes * fix * big endian fix * Moving to the new tag_invoke signature * Fix nlohmann ambiguity on C++23-enabled clang * Revert "Merge branch 'master' of https://github.com/simdjson/simdjson into builder_development_branch_extra" This reverts commit `3eeecbab34`, reversing changes made to `6858b208b4`. --------- Co-authored-by: Daniel Lemire <daniel@lemire.me> Co-authored-by: Sasha Lopoukhine <superlopuh@gmail.com> Co-authored-by: John Keiser <john@johnkeiser.com> Co-authored-by: Tan Li Boon <undisputed-seraphim@users.noreply.github.com> Co-authored-by: tobil4sk <tobil4sk@outlook.com>	2024-09-24 14:47:58 -04:00
Daniel Lemire	0388d79770	Extending the deserialization code with more defaults + docs (#2233 ) * Make custom types easier with some predefined cases + docs * missing include * adding Ubuntu 24 CXX 20 * using concepts all the way * minor tweak * tiny tweak * tweaks * more tweaking * saving --------- Co-authored-by: Daniel Lemire <dlemire@lemire.me>	2024-08-11 14:14:35 -04:00
Daniel Lemire	c0fa1aec66	fix: correct small issues with deserialize (#2232 )	2024-08-09 16:07:08 -04:00
M. Bahoosh	6e61b7f6ef	Making `tag_invoke` to support `ondemand::document` as well + docs (#2228 ) * Making `tag_invoke` to support `ondemand::document` as well + docs * Fix typos and doc update by @lemire Co-authored-by: Daniel Lemire <daniel@lemire.me> * Better docs by @lemire Co-authored-by: Daniel Lemire <daniel@lemire.me> * Preserving the old, disallowing in the new I'm disabling `document::get() &&` if the user has provided a `tag_invoke`d version; otherwise, we retain the compatibility. --------- Co-authored-by: Daniel Lemire <daniel@lemire.me>	2024-08-09 15:25:52 -04:00
M. Bahoosh	a76e778804	tag_invoke based custom types (#2219 ) * tag_invoke based custom types Now you can use tag_invoke to add a custom type or a group of custom types. * Fixing macro usage + Fixing noexcept * Fixing the usage of #include We don't need <concepts> at all seems like it * Fixing tag_invoke impl for MSVC	2024-08-07 09:16:31 -04:00