sync

Merge branch 'master' of github.com:simdjson/simdjson
release candidate 3.11.2
2026-06-08 17:27:07 +00:00 · 2024-12-09 21:36:43 -05:00 · 2024-12-09 21:36:12 -05:00 · 2024-12-09 21:35:21 -05:00 · 2024-12-09 10:20:33 -05:00 · 2024-12-07 11:13:00 -05:00
58 changed files with 12123 additions and 5373 deletions
@@ -1,9 +1,8 @@
 name: Doxygen GitHub Pages

 on:
-  push:
-    branches:
-      - master
+  release:
+    types: [created]
  # Allows you to run this workflow manually from the Actions tab
  workflow_dispatch:

@@ -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: ${{matrix.cxx}}
+      - name: Build
+        run: cmake --build build -j=2
+      - name: Test
+        run: ctest --output-on-failure --test-dir build
@@ -10,7 +10,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-           - {arch: ARM}
           - {arch: ARM64}
           - {arch: ARM64EC}
     steps:
@@ -0,0 +1,37 @@
+name: VS17-CLANG-CI
+
+on: [push, pull_request]
+
+jobs:
+  ci:
+    if: >-
+      ! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
+      ! contains(toJSON(github.event.commits.*.message), '[skip github]')
+    name: windows-vs17
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: Debug}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: Release}
+          - {gen: Visual Studio 17 2022, arch: x64, build_type: RelWithDebInfo}
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: Configure
+      run: |
+        cmake -G "${{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}}
@@ -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 3.11.2
    DESCRIPTION "Parsing gigabytes of JSON per second"
    HOMEPAGE_URL "https://simdjson.org/"
    LANGUAGES CXX C
@@ -20,8 +20,8 @@ string(
 # ---- Options, variables ----

 # These version numbers are modified by tools/release.py
-set(SIMDJSON_LIB_VERSION "23.0.0" CACHE STRING "simdjson library version")
-set(SIMDJSON_LIB_SOVERSION "23" CACHE STRING "simdjson library soversion")
+set(SIMDJSON_LIB_VERSION "24.0.0" CACHE STRING "simdjson library version")
+set(SIMDJSON_LIB_SOVERSION "24" 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)
@@ -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         = "3.11.2"

 # 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
@@ -31,6 +31,7 @@ Table of Contents
 * [Documentation](#documentation)
 * [Godbolt](#godbolt)
 * [Performance results](#performance-results)
+* [Packages](#packages)
 * [Bindings and Ports of simdjson](#bindings-and-ports-of-simdjson)
 * [About simdjson](#about-simdjson)
 * [Funding](#funding)
@@ -143,6 +144,9 @@ speed for [synthetic files over various sizes generated with a script](https://g
 For NDJSON files, we can exceed 3 GB/s with [our  multithreaded parsing functions](https://github.com/simdjson/simdjson/blob/master/doc/parse_many.md).


+Packages
+------------------------------
+[![Packaging status](https://repology.org/badge/vertical-allrepos/simdjson.svg)](https://repology.org/project/simdjson/versions)


 Bindings and Ports of simdjson
@@ -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;
      }
    }
@@ -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)
@@ -207,6 +209,25 @@ std::string data = "my data";
 simdjson::padded_string my_padded_data(data); // copies to a padded buffer
 ```

+You can then parse the JSON data from the `simdjson::padded_string` instance:
+
+
+```c++
+ondemand::document doc = parser.iterate(my_padded_data);
+```
+
+Whenever you pass an `std::string` reference to `parser::iterate`,
+the parser will access the bytes beyond the end of
+the string but before the end of the allocated memory (`std::string::capacity()`).
+If you are using a sanitizer that checks for reading uninitialized bytes or `std::string`'s
+container-overflow checks, you may encounter sanitizer warnings.
+You can safely ignore these warnings. Or you can call `simdjson::pad(std::string&)` to pad the
+string with `SIMDJSON_PADDING` spaces: this function returns a `simdjson::padding_string_view` which can be be passed to the parser's iterator function:
+
+```c++
+std::string json = "[1]";
+ondemand::document doc = parser.iterate(simdjson::pad(json));
+```

 We recommend against creating many `std::string` or many `std::padding_string` instances in your application to store your JSON data.
 Consider reusing the same buffers and limiting memory allocations.
@@ -526,7 +547,7 @@ 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*.
@@ -536,7 +557,7 @@ support for users who avoid exceptions. See [the simdjson error handling documen
  For this purpose, `array` instances have a `count_elements` method. Users should be
  aware that the `count_elements` method can be costly since it requires scanning the
  whole array. You should only call `count_elements` as a last resort as it may
-  require scanning the document twice or more. You may use it as follows if your document is itself an array:
+  require scanning the document twice or more. In the spirit of On-Demand, the `count_elements` function does not validate the values in the array. You may use it as follows if your document is itself an array:

  ```C++
  auto cars_json = R"( [ 40.1, 39.9, 37.7, 40.4 ] )"_padded;
@@ -788,6 +809,18 @@ 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 +854,15 @@ 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 +878,7 @@ simdjson::ondemand::value::get() noexcept {
  }
  return vec;
 }
+#endif
 ```

 We may then provide support for our `Car` struct:
@@ -850,26 +890,10 @@ 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 +917,8 @@ 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 +934,7 @@ simdjson::ondemand::value::get() noexcept {
  }
  return vec;
 }
-
+#endif

 template <>
 simdjson_inline simdjson_result<Car> simdjson::ondemand::value::get() noexcept {
@@ -916,26 +942,10 @@ 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 +960,14 @@ 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 +983,11 @@ 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 +1018,49 @@ 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 +1075,219 @@ 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 +1303,7 @@ 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.
 ```

@@ -1292,7 +1515,7 @@ 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.
@@ -1323,7 +1546,7 @@ 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;
@@ -1357,7 +1580,7 @@ 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": [
    {
@@ -1376,7 +1599,6 @@ 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"
@@ -1384,10 +1606,10 @@ 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) {
@@ -1418,12 +1640,12 @@ 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;
 }
 ```
@@ -1447,40 +1669,40 @@ 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;
@@ -1602,7 +1824,7 @@ 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);
@@ -1639,7 +1861,7 @@ 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)
 }
 ```
@@ -1812,7 +2034,7 @@ 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;
@@ -60,6 +60,26 @@ std::string data = "my data";
 simdjson::padded_string my_padded_data(data); // copies to a padded buffer
 ```

+You can then parse the JSON document from the `simdjson::padded_string` instance:
+
+```cpp
+simdjson::dom::parser parser;
+simdjson::dom::element doc = parser.parse(my_padded_data);
+```
+
+Whenever you pass an `std::string` reference to `parser::parse`,
+the parser will access the bytes beyond the end of
+the string but before the end of the allocated memory (`std::string::capacity()`).
+If you are using a sanitizer that checks for reading uninitialized bytes or `std::string`'s
+container-overflow checks, you may encounter sanitizer warnings.
+You can safely ignore these warnings. Or you can call `simdjson::pad(std::string&)` to pad the
+string with `SIMDJSON_PADDING` spaces: this function returns a `simdjson::padding_string_view` which can be be passed to the parser's iterator function:
+
+```c++
+std::string json = "[1]";
+dom::element doc = parser.parse(simdjson::pad(json));
+```
+
 The parsed document resulting from the `parser.load` and `parser.parse` calls depends on the `parser` instance. Thus the `parser` instance must remain in scope. Furthermore, you must have at most one parsed document in play per `parser` instance.
 You cannot copy a `parser` instance, you may only move it.

@@ -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
 -----------
@@ -293,3 +294,111 @@ 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);
+  }
+```
@@ -53,5 +53,4 @@

 #include "simdjson/dom.h"
 #include "simdjson/ondemand.h"
-
 #endif // SIMDJSON_H
@@ -19,7 +19,7 @@ SIMDJSON_NO_SANITIZE_UNDEFINED
 // See issue https://github.com/simdjson/simdjson/issues/1965
 SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  unsigned long ret;
  // Search the mask data from least significant bit (LSB)
  // to the most significant bit (MSB) for a set bit (1).
@@ -43,7 +43,7 @@ simdjson_inline uint64_t clear_lowest_bit(uint64_t input_num) {
 SIMDJSON_NO_SANITIZE_UNDEFINED
 /* result might be undefined when input_num is zero */
 simdjson_inline int leading_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  unsigned long leading_zero = 0;
  // Search the mask data from most significant bit (MSB)
  // to least significant bit (LSB) for a set bit (1).
@@ -96,7 +96,7 @@ simdjson_inline uint64_t zero_leading_bit(uint64_t rev_bits, int leading_zeroes)
 #endif

 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2, uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  *result = value1 + value2;
  return *result < value1;
 #else
@@ -12,7 +12,7 @@ namespace arm64 {
 namespace {
 namespace simd {

-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 namespace {
 // Start of private section with Visual Studio workaround

@@ -121,7 +121,7 @@ namespace {
    // We return uint32_t instead of uint16_t because that seems to be more efficient for most
    // purposes (cutting it down to uint16_t costs performance in some compilers).
    simdjson_inline uint32_t to_bitmask() const {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      const uint8x16_t bit_mask =  simdjson_make_uint8x16_t(0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
                                                   0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80);
 #else
@@ -152,7 +152,7 @@ namespace {
    // Splat constructor
    simdjson_inline simd8(uint8_t _value) : simd8(splat(_value)) {}
    // Member-by-member initialization
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
    simdjson_inline simd8(
      uint8_t v0,  uint8_t v1,  uint8_t v2,  uint8_t v3,  uint8_t v4,  uint8_t v5,  uint8_t v6,  uint8_t v7,
      uint8_t v8,  uint8_t v9,  uint8_t v10, uint8_t v11, uint8_t v12, uint8_t v13, uint8_t v14, uint8_t v15
@@ -246,7 +246,7 @@ namespace {
      uint64x2_t shufmask64 = {thintable_epi8[mask1], thintable_epi8[mask2]};
      uint8x16_t shufmask = vreinterpretq_u8_u64(shufmask64);
      // we increment by 0x08 the second half of the mask
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      uint8x16_t inc = simdjson_make_uint8x16_t(0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08);
 #else
      uint8x16_t inc = {0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08};
@@ -276,7 +276,7 @@ namespace {
      uint8x8_t compactmask1 = vcreate_u8(thintable_epi8[mask1]);
      uint8x8_t compactmask2 = vcreate_u8(thintable_epi8[mask2]);
      // we increment by 0x08 the second half of the mask
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      uint8x8_t inc = simdjson_make_uint8x8_t(0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08);
 #else
      uint8x8_t inc = {0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08};
@@ -328,7 +328,7 @@ namespace {
    // Array constructor
    simdjson_inline simd8(const int8_t* values) : simd8(load(values)) {}
    // Member-by-member initialization
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
    simdjson_inline simd8(
      int8_t v0,  int8_t v1,  int8_t v2,  int8_t v3, int8_t v4,  int8_t v5,  int8_t v6,  int8_t v7,
      int8_t v8,  int8_t v9,  int8_t v10, int8_t v11, int8_t v12, int8_t v13, int8_t v14, int8_t v15
@@ -449,7 +449,7 @@ namespace {
    }

    simdjson_inline uint64_t to_bitmask() const {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      const uint8x16_t bit_mask = simdjson_make_uint8x16_t(
        0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
        0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80
@@ -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.
@@ -50,4 +50,16 @@
 #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
@@ -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
@@ -372,6 +372,8 @@ public:
   *         - INCORRECT_TYPE if this is not an object
   */
  inline simdjson_result<element> operator[](const char *key) const noexcept;
+  simdjson_result<element> operator[](int) const noexcept = delete;
+

  /**
   * Get the value associated with the given JSON pointer.  We use the RFC 6901
@@ -540,6 +542,7 @@ public:

  simdjson_inline simdjson_result<dom::element> operator[](std::string_view key) const noexcept;
  simdjson_inline simdjson_result<dom::element> operator[](const char *key) const noexcept;
+  simdjson_result<dom::element> operator[](int) const noexcept = delete;
  simdjson_inline simdjson_result<dom::element> at_pointer(const std::string_view json_pointer) const noexcept;
  simdjson_inline simdjson_result<dom::element> at_path(const std::string_view json_path) const noexcept;
  [[deprecated("For standard compliance, use at_pointer instead, and prefix your pointers with a slash '/', see RFC6901 ")]]
@@ -145,6 +145,7 @@ public:
   *         - INCORRECT_TYPE if this is not an object
   */
  inline simdjson_result<element> operator[](const char *key) const noexcept;
+  simdjson_result<element> operator[](int) const noexcept = delete;

  /**
   * Get the value associated with the given JSON pointer. We use the RFC 6901
@@ -258,6 +259,7 @@ public:

  inline simdjson_result<dom::element> operator[](std::string_view key) const noexcept;
  inline simdjson_result<dom::element> operator[](const char *key) const noexcept;
+  simdjson_result<dom::element> operator[](int) const noexcept = delete;
  inline simdjson_result<dom::element> at_pointer(std::string_view json_pointer) const noexcept;
  inline simdjson_result<dom::element> at_path(std::string_view json_path) const noexcept;
  inline simdjson_result<dom::element> at_key(std::string_view key) const noexcept;
@@ -202,6 +202,22 @@ public:
   *   simdjson::dom::parser parser;
   *   simdjson::dom::element element = parser.parse(padded_json_copy.get(), json_len, false);
   *
+   * ### std::string references
+   *
+   * If you pass a mutable std::string reference (std::string&), the parser will seek to extend
+   * its capacity to SIMDJSON_PADDING bytes beyond the end of the string.
+   *
+   * Whenever you pass an std::string reference, the parser will access the bytes beyond the end of
+   * the string but before the end of the allocated memory (std::string::capacity()).
+   * If you are using a sanitizer that checks for reading uninitialized bytes or std::string's
+   * container-overflow checks, you may encounter sanitizer warnings.
+   * You can safely ignore these warnings. Or you can call simdjson::pad(std::string&) to pad the
+   * string with SIMDJSON_PADDING spaces: this function returns a simdjson::padding_string_view
+   * which can be be passed to the parser's parse function:
+   *
+   *    std::string json = R"({ "foo": 1 } { "foo": 2 } { "foo": 3 } )";
+   *    element doc = parser.parse(simdjson::pad(json));
+   *
   * ### Parser Capacity
   *
   * If the parser's current capacity is less than len, it will allocate enough capacity
@@ -86,7 +86,7 @@ struct simdjson_error : public std::exception {
   */
  simdjson_error(error_code error) noexcept : _error{error} { }
  /** The error message */
-  const char *what() const noexcept { return error_message(error()); }
+  const char *what() const noexcept override { return error_message(error()); }
  /** The error code */
  error_code error() const noexcept { return _error; }
 private:
@@ -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"
+
+
@@ -44,7 +44,8 @@ public:
   * calling this function, if successful, the array is 'rewinded' at its
   * beginning as if it had never been accessed. If the JSON is malformed (e.g.,
   * there is a missing comma), then an error is returned and it is no longer
-   * safe to continue.
+   * safe to continue. Note that count_elements() does not validate the JSON values,
+   * only the structure of the array.
   *
   * To check that an array is empty, it is more performant to use
   * the is_empty() method.
@@ -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
+
@@ -8,10 +8,12 @@
 #include "simdjson/generic/ondemand/json_type.h"
 #include "simdjson/generic/ondemand/raw_json_string.h"
 #include "simdjson/generic/ondemand/value.h"
+#include "simdjson/generic/ondemand/value-inl.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_iterator-inl.h"
+#include "simdjson/generic/ondemand/deserialize.h"
 #endif // SIMDJSON_CONDITIONAL_INCLUDE

 namespace simdjson {
@@ -165,6 +167,16 @@ template<> simdjson_inline simdjson_result<int64_t> document::get() & noexcept {
 template<> simdjson_inline simdjson_result<bool> document::get() & noexcept { return get_bool(); }
 template<> simdjson_inline simdjson_result<value> document::get() & noexcept { return get_value(); }

+template<> simdjson_inline error_code document::get(array& out) & noexcept { return get_array().get(out); }
+template<> simdjson_inline error_code document::get(object& out) & noexcept { return get_object().get(out); }
+template<> simdjson_inline error_code document::get(raw_json_string& out) & noexcept { return get_raw_json_string().get(out); }
+template<> simdjson_inline error_code document::get(std::string_view& out) & noexcept { return get_string(false).get(out); }
+template<> simdjson_inline error_code document::get(double& out) & noexcept { return get_double().get(out); }
+template<> simdjson_inline error_code document::get(uint64_t& out) & noexcept { return get_uint64().get(out); }
+template<> simdjson_inline error_code document::get(int64_t& out) & noexcept { return get_int64().get(out); }
+template<> simdjson_inline error_code document::get(bool& out) & noexcept { return get_bool().get(out); }
+template<> simdjson_inline error_code document::get(value& out) & noexcept { return get_value().get(out); }
+
 template<> simdjson_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(); }
@@ -173,13 +185,6 @@ template<> simdjson_deprecated simdjson_inline simdjson_result<int64_t> document
 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<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>(); }
@@ -818,6 +823,26 @@ 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 +855,18 @@ 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 +884,12 @@ 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>();
  }

  /**
@@ -209,7 +227,32 @@ 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, 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;

@@ -311,7 +354,8 @@ public:
   * calling this function, if successful, the array is 'rewinded' at its
   * beginning as if it had never been accessed. If the JSON is malformed (e.g.,
   * there is a missing comma), then an error is returned and it is no longer
-   * safe to continue.
+   * safe to continue. Note that count_elements() does not validate the JSON values,
+   * only the structure of the array.
   */
  simdjson_inline simdjson_result<size_t> count_elements() & noexcept;
   /**
@@ -423,6 +467,7 @@ public:
  simdjson_inline simdjson_result<value> operator[](std::string_view key) & noexcept;
  /** @overload simdjson_inline simdjson_result<value> find_field_unordered(std::string_view key) & noexcept; */
  simdjson_inline simdjson_result<value> operator[](const char *key) & noexcept;
+ simdjson_result<value> operator[](int) & noexcept = delete;

  /**
   * Get the type of this JSON value. It does not validate or consume the value.
@@ -721,7 +766,70 @@ 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
@@ -746,6 +854,7 @@ public:
  simdjson_inline simdjson_result<value> find_field(const char *key) & noexcept;
  simdjson_inline simdjson_result<value> operator[](std::string_view key) & noexcept;
  simdjson_inline simdjson_result<value> operator[](const char *key) & noexcept;
+  simdjson_result<value> operator[](int) & noexcept = delete;
  simdjson_inline simdjson_result<value> find_field_unordered(std::string_view key) & noexcept;
  simdjson_inline simdjson_result<value> find_field_unordered(const char *key) & noexcept;

@@ -824,6 +933,7 @@ public:
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field(const char *key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](std::string_view key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](const char *key) & noexcept;
+  simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](int) & noexcept = delete;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field_unordered(std::string_view key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field_unordered(const char *key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::json_type> type() noexcept;
@@ -873,8 +983,14 @@ 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);
@@ -895,6 +1011,7 @@ public:
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field(const char *key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](std::string_view key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](const char *key) & noexcept;
+  simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](int) & noexcept = delete;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field_unordered(std::string_view key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field_unordered(const char *key) & noexcept;
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::json_type> type() noexcept;
@@ -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);
 }

@@ -84,6 +84,22 @@ public:
   * using a sanitizer that verifies that no uninitialized byte is read, then you should initialize the
   * SIMDJSON_PADDING bytes to avoid runtime warnings.
   *
+   * ### std::string references
+   *
+   * If you pass a mutable std::string reference (std::string&), the parser will seek to extend
+   * its capacity to SIMDJSON_PADDING bytes beyond the end of the string.
+   *
+   * Whenever you pass an std::string reference, the parser will access the bytes beyond the end of
+   * the string but before the end of the allocated memory (std::string::capacity()).
+   * If you are using a sanitizer that checks for reading uninitialized bytes or std::string's
+   * container-overflow checks, you may encounter sanitizer warnings.
+   * You can safely ignore these warnings. Or you can call simdjson::pad(std::string&) to pad the
+   * string with SIMDJSON_PADDING spaces: this function returns a simdjson::padding_string_view
+   * which can be be passed to the parser's iterate function:
+   *
+   *    std::string json = R"({ "foo": 1 } { "foo": 2 } { "foo": 3 } )";
+   *    document doc = parser.iterate(simdjson::pad(json));
+   *
   * @param json The JSON to parse.
   * @param len The length of the JSON.
   * @param capacity The number of bytes allocated in the JSON (must be at least len+SIMDJSON_PADDING).
@@ -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
@@ -78,6 +78,7 @@ 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 +89,16 @@ 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 +422,12 @@ 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 +441,6 @@ 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 +474,7 @@ 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.
@@ -130,6 +163,17 @@ public:
   * Important: a value should be consumed once. Calling get_string() twice on the same value
   * is an error.
   *
+   * In some instances, you may want to allow replacement of invalid Unicode sequences.
+   * You may do so by passing the allow_replacement parameter as true. In the following
+   * example, the string "431924697b\udff0L\u0001Y" is not valid Unicode. By passing true
+   * to get_string, we allow the replacement of the invalid Unicode sequences with the Unicode
+   * replacement character (U+FFFD).
+   *
+   *   simdjson::ondemand::parser parser;
+   *   auto json = R"({"deviceId":"431924697b\udff0L\u0001Y"})"_padded;
+   *   simdjson::ondemand::document doc = parser.iterate(json);
+   *   auto view = doc["deviceId"].get_string(true);
+   *
   * @returns An UTF-8 string. The string is stored in the parser and will be invalidated the next
   *          time it parses a document or when it is destroyed.
   * @returns INCORRECT_TYPE if the JSON value is not a string.
@@ -381,6 +425,7 @@ public:
  simdjson_inline simdjson_result<value> operator[](std::string_view key) noexcept;
  /** @overload simdjson_inline simdjson_result<value> find_field_unordered(std::string_view key) noexcept; */
  simdjson_inline simdjson_result<value> operator[](const char *key) noexcept;
+  simdjson_result<value> operator[](int) noexcept = delete;

  /**
   * Get the type of this JSON value. It does not validate or consume the value.
@@ -748,6 +793,7 @@ public:
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](std::string_view key) noexcept;
  /** @overload simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> find_field_unordered(std::string_view key) noexcept; */
  simdjson_inline simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](const char *key) noexcept;
+  simdjson_result<SIMDJSON_IMPLEMENTATION::ondemand::value> operator[](int) noexcept = delete;

  /**
   * Get the type of this JSON value.
@@ -187,11 +187,11 @@ inline simdjson_result<padded_string> padded_string::load(std::string_view filen

 } // namespace simdjson

-inline simdjson::padded_string operator "" _padded(const char *str, size_t len) {
+inline simdjson::padded_string operator ""_padded(const char *str, size_t len) {
  return simdjson::padded_string(str, len);
 }
 #ifdef __cpp_char8_t
-inline simdjson::padded_string operator "" _padded(const char8_t *str, size_t len) {
+inline simdjson::padded_string operator ""_padded(const char8_t *str, size_t len) {
  return simdjson::padded_string(reinterpret_cast<const char8_t *>(str), len);
 }
 #endif
@@ -161,9 +161,9 @@ inline std::ostream& operator<<(std::ostream& out, simdjson_result<padded_string
 } // namespace simdjson

 // This is deliberately outside of simdjson so that people get it without having to use the namespace
-inline simdjson::padded_string operator "" _padded(const char *str, size_t len);
+inline simdjson::padded_string operator ""_padded(const char *str, size_t len);
 #ifdef __cpp_char8_t
-inline simdjson::padded_string operator "" _padded(const char8_t *str, size_t len);
+inline simdjson::padded_string operator ""_padded(const char8_t *str, size_t len);
 #endif

 namespace simdjson {
@@ -53,6 +53,11 @@ inline bool padded_string_view::remove_utf8_bom() noexcept {
 inline std::ostream& operator<<(std::ostream& out, simdjson_result<padded_string_view> &s) noexcept(false) { return out << s.value(); }
 #endif

+inline padded_string_view pad(std::string& s) noexcept {
+  const auto len = s.size();
+  s.append(SIMDJSON_PADDING, ' ');
+  return padded_string_view(s.data(), len, s.size());
+}
 } // namespace simdjson


@@ -83,6 +83,15 @@ public:
 inline std::ostream& operator<<(std::ostream& out, simdjson_result<padded_string_view> &s) noexcept(false);
 #endif

+/**
+ * Create a padded_string_view from a string. The string will be padded with SIMDJSON_PADDING
+ * space characters. The resulting padded_string_view will have a length equal to the original
+ * string.
+ *
+ * @param s The string.
+ * @return The padded string.
+ */
+inline padded_string_view pad(std::string& s) noexcept;
 } // namespace simdjson

 #endif // SIMDJSON_PADDED_STRING_VIEW_H
@@ -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 "3.11.2"

 namespace simdjson {
 enum {
@@ -15,11 +15,11 @@ enum {
  /**
   * The minor version (major.MINOR.revision) of simdjson being used.
   */
-  SIMDJSON_VERSION_MINOR = 10,
+  SIMDJSON_VERSION_MINOR = 11,
  /**
   * The revision (major.minor.REVISION) of simdjson being used.
   */
-  SIMDJSON_VERSION_REVISION = 1
+  SIMDJSON_VERSION_REVISION = 2
 };
 } // namespace simdjson

@@ -1,4 +1,4 @@
-/* auto-generated on 2024-09-17 15:48:50 -0400. Do not edit! */
+/* auto-generated on 2024-12-09 21:36:12 -0500. 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" */
@@ -2468,7 +2480,7 @@ struct simdjson_error : public std::exception {
   */
  simdjson_error(error_code error) noexcept : _error{error} { }
  /** The error message */
-  const char *what() const noexcept { return error_message(error()); }
+  const char *what() const noexcept override { return error_message(error()); }
  /** The error code */
  error_code error() const noexcept { return _error; }
 private:
@@ -2700,6 +2712,122 @@ 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.
@@ -6485,7 +6613,6 @@ 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> */
@@ -7661,7 +7788,7 @@ SIMDJSON_NO_SANITIZE_UNDEFINED
 // See issue https://github.com/simdjson/simdjson/issues/1965
 SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  unsigned long ret;
  // Search the mask data from least significant bit (LSB)
  // to the most significant bit (MSB) for a set bit (1).
@@ -7685,7 +7812,7 @@ simdjson_inline uint64_t clear_lowest_bit(uint64_t input_num) {
 SIMDJSON_NO_SANITIZE_UNDEFINED
 /* result might be undefined when input_num is zero */
 simdjson_inline int leading_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  unsigned long leading_zero = 0;
  // Search the mask data from most significant bit (MSB)
  // to least significant bit (LSB) for a set bit (1).
@@ -7738,7 +7865,7 @@ simdjson_inline uint64_t zero_leading_bit(uint64_t rev_bits, int leading_zeroes)
 #endif

 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2, uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  *result = value1 + value2;
  return *result < value1;
 #else
@@ -7881,7 +8008,7 @@ namespace arm64 {
 namespace {
 namespace simd {

-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 namespace {
 // Start of private section with Visual Studio workaround

@@ -7990,7 +8117,7 @@ namespace {
    // We return uint32_t instead of uint16_t because that seems to be more efficient for most
    // purposes (cutting it down to uint16_t costs performance in some compilers).
    simdjson_inline uint32_t to_bitmask() const {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      const uint8x16_t bit_mask =  simdjson_make_uint8x16_t(0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
                                                   0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80);
 #else
@@ -8021,7 +8148,7 @@ namespace {
    // Splat constructor
    simdjson_inline simd8(uint8_t _value) : simd8(splat(_value)) {}
    // Member-by-member initialization
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
    simdjson_inline simd8(
      uint8_t v0,  uint8_t v1,  uint8_t v2,  uint8_t v3,  uint8_t v4,  uint8_t v5,  uint8_t v6,  uint8_t v7,
      uint8_t v8,  uint8_t v9,  uint8_t v10, uint8_t v11, uint8_t v12, uint8_t v13, uint8_t v14, uint8_t v15
@@ -8115,7 +8242,7 @@ namespace {
      uint64x2_t shufmask64 = {thintable_epi8[mask1], thintable_epi8[mask2]};
      uint8x16_t shufmask = vreinterpretq_u8_u64(shufmask64);
      // we increment by 0x08 the second half of the mask
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      uint8x16_t inc = simdjson_make_uint8x16_t(0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08);
 #else
      uint8x16_t inc = {0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08};
@@ -8145,7 +8272,7 @@ namespace {
      uint8x8_t compactmask1 = vcreate_u8(thintable_epi8[mask1]);
      uint8x8_t compactmask2 = vcreate_u8(thintable_epi8[mask2]);
      // we increment by 0x08 the second half of the mask
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      uint8x8_t inc = simdjson_make_uint8x8_t(0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08);
 #else
      uint8x8_t inc = {0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08};
@@ -8197,7 +8324,7 @@ namespace {
    // Array constructor
    simdjson_inline simd8(const int8_t* values) : simd8(load(values)) {}
    // Member-by-member initialization
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
    simdjson_inline simd8(
      int8_t v0,  int8_t v1,  int8_t v2,  int8_t v3, int8_t v4,  int8_t v5,  int8_t v6,  int8_t v7,
      int8_t v8,  int8_t v9,  int8_t v10, int8_t v11, int8_t v12, int8_t v13, int8_t v14, int8_t v15
@@ -8318,7 +8445,7 @@ namespace {
    }

    simdjson_inline uint64_t to_bitmask() const {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      const uint8x16_t bit_mask = simdjson_make_uint8x16_t(
        0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
        0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80
@@ -10428,7 +10555,7 @@ SIMDJSON_NO_SANITIZE_UNDEFINED
 // See issue https://github.com/simdjson/simdjson/issues/1965
 SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  unsigned long ret;
  // Search the mask data from least significant bit (LSB)
  // to the most significant bit (MSB) for a set bit (1).
@@ -10452,7 +10579,7 @@ simdjson_inline uint64_t clear_lowest_bit(uint64_t input_num) {
 SIMDJSON_NO_SANITIZE_UNDEFINED
 /* result might be undefined when input_num is zero */
 simdjson_inline int leading_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  unsigned long leading_zero = 0;
  // Search the mask data from most significant bit (MSB)
  // to least significant bit (LSB) for a set bit (1).
@@ -10505,7 +10632,7 @@ simdjson_inline uint64_t zero_leading_bit(uint64_t rev_bits, int leading_zeroes)
 #endif

 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2, uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
  *result = value1 + value2;
  return *result < value1;
 #else
@@ -10648,7 +10775,7 @@ namespace arm64 {
 namespace {
 namespace simd {

-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 namespace {
 // Start of private section with Visual Studio workaround

@@ -10757,7 +10884,7 @@ namespace {
    // We return uint32_t instead of uint16_t because that seems to be more efficient for most
    // purposes (cutting it down to uint16_t costs performance in some compilers).
    simdjson_inline uint32_t to_bitmask() const {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      const uint8x16_t bit_mask =  simdjson_make_uint8x16_t(0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
                                                   0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80);
 #else
@@ -10788,7 +10915,7 @@ namespace {
    // Splat constructor
    simdjson_inline simd8(uint8_t _value) : simd8(splat(_value)) {}
    // Member-by-member initialization
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
    simdjson_inline simd8(
      uint8_t v0,  uint8_t v1,  uint8_t v2,  uint8_t v3,  uint8_t v4,  uint8_t v5,  uint8_t v6,  uint8_t v7,
      uint8_t v8,  uint8_t v9,  uint8_t v10, uint8_t v11, uint8_t v12, uint8_t v13, uint8_t v14, uint8_t v15
@@ -10882,7 +11009,7 @@ namespace {
      uint64x2_t shufmask64 = {thintable_epi8[mask1], thintable_epi8[mask2]};
      uint8x16_t shufmask = vreinterpretq_u8_u64(shufmask64);
      // we increment by 0x08 the second half of the mask
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      uint8x16_t inc = simdjson_make_uint8x16_t(0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08);
 #else
      uint8x16_t inc = {0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08};
@@ -10912,7 +11039,7 @@ namespace {
      uint8x8_t compactmask1 = vcreate_u8(thintable_epi8[mask1]);
      uint8x8_t compactmask2 = vcreate_u8(thintable_epi8[mask2]);
      // we increment by 0x08 the second half of the mask
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      uint8x8_t inc = simdjson_make_uint8x8_t(0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08);
 #else
      uint8x8_t inc = {0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08};
@@ -10964,7 +11091,7 @@ namespace {
    // Array constructor
    simdjson_inline simd8(const int8_t* values) : simd8(load(values)) {}
    // Member-by-member initialization
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
    simdjson_inline simd8(
      int8_t v0,  int8_t v1,  int8_t v2,  int8_t v3, int8_t v4,  int8_t v5,  int8_t v6,  int8_t v7,
      int8_t v8,  int8_t v9,  int8_t v10, int8_t v11, int8_t v12, int8_t v13, int8_t v14, int8_t v15
@@ -11085,7 +11212,7 @@ namespace {
    }

    simdjson_inline uint64_t to_bitmask() const {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
      const uint8x16_t bit_mask = simdjson_make_uint8x16_t(
        0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
        0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80
@@ -14038,6 +14165,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool allow_replacement) const noexcept {
  return arm64::stringparsing::parse_string(src, dst, allow_replacement);
 }
@@ -14176,8 +14304,14 @@ static_assert(sizeof(__m256i) <= simdjson::SIMDJSON_PADDING, "insufficient paddi
 /* end file simdjson/haswell/intrinsics.h */

 #if !SIMDJSON_CAN_ALWAYS_RUN_HASWELL
+// We enable bmi2 only if LLVM/clang is used, because GCC may not
+// make good use of it. See https://github.com/simdjson/simdjson/pull/2243
+#if defined(__clang__)
+SIMDJSON_TARGET_REGION("avx2,bmi,bmi2,pclmul,lzcnt,popcnt")
+#else
 SIMDJSON_TARGET_REGION("avx2,bmi,pclmul,lzcnt,popcnt")
 #endif
+#endif

 /* including simdjson/haswell/bitmanipulation.h: #include "simdjson/haswell/bitmanipulation.h" */
 /* begin file simdjson/haswell/bitmanipulation.h */
@@ -16808,8 +16942,14 @@ static_assert(sizeof(__m256i) <= simdjson::SIMDJSON_PADDING, "insufficient paddi
 /* end file simdjson/haswell/intrinsics.h */

 #if !SIMDJSON_CAN_ALWAYS_RUN_HASWELL
+// We enable bmi2 only if LLVM/clang is used, because GCC may not
+// make good use of it. See https://github.com/simdjson/simdjson/pull/2243
+#if defined(__clang__)
+SIMDJSON_TARGET_REGION("avx2,bmi,bmi2,pclmul,lzcnt,popcnt")
+#else
 SIMDJSON_TARGET_REGION("avx2,bmi,pclmul,lzcnt,popcnt")
 #endif
+#endif

 /* including simdjson/haswell/bitmanipulation.h: #include "simdjson/haswell/bitmanipulation.h" */
 /* begin file simdjson/haswell/bitmanipulation.h */
@@ -20253,6 +20393,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return haswell::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -26507,6 +26648,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return icelake::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -32931,6 +33073,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return ppc64::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -40019,6 +40162,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return westmere::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -46016,6 +46160,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool allow_replacement) const noexcept {
  return lsx::stringparsing::parse_string(src, dst, allow_replacement);
 }
@@ -52038,6 +52183,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool allow_replacement) const noexcept {
  return lasx::stringparsing::parse_string(src, dst, allow_replacement);
 }
@@ -56011,6 +56157,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return fallback::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -150,6 +150,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool allow_replacement) const noexcept {
  return arm64::stringparsing::parse_string(src, dst, allow_replacement);
 }
@@ -388,6 +388,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return fallback::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -147,6 +147,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return haswell::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -193,6 +193,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return icelake::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -110,6 +110,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool allow_replacement) const noexcept {
  return lasx::stringparsing::parse_string(src, dst, allow_replacement);
 }
@@ -114,6 +114,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool allow_replacement) const noexcept {
  return lsx::stringparsing::parse_string(src, dst, allow_replacement);
 }
@@ -120,6 +120,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return ppc64::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -152,6 +152,7 @@ simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::docu
  return stage2::tape_builder::parse_document<true>(*this, _doc);
 }

+SIMDJSON_NO_SANITIZE_MEMORY
 simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {
  return westmere::stringparsing::parse_string(src, dst, replacement_char);
 }
@@ -461,6 +461,13 @@ void parse_documentation_lowlevel() {
  (void)element;
 }

+void simplepad() {
+  std::string json = "[1]";
+  dom::parser parser;
+  dom::element doc;
+  auto error = parser.parse(simdjson::pad(json)).get(doc);
+  if(error) { exit(-1); }
+}

 void jsondollar() {
  dom::parser parser;
@@ -497,6 +504,7 @@ void jsonpath() {
 }

 int main() {
+  simplepad();
  jsonpath();
  jsondollar();
  basics_dom_1();
@@ -2,32 +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_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()
@@ -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
@@ -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);
+}
@@ -8,7 +8,15 @@
 #endif
 using namespace std;
 using namespace simdjson;
-using error_code=simdjson::error_code;
+using error_code = simdjson::error_code;
+
+bool simplepad() {
+  std::string json = "[1]";
+  ondemand::parser parser;
+  ondemand::document doc;
+  auto error = parser.iterate(simdjson::pad(json)).get(doc);
+  return error == SUCCESS;
+}

 bool string1() {
  const char * data = "my data"; // 7 bytes
@@ -49,6 +57,7 @@ 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 +75,7 @@ simdjson::ondemand::value::get() noexcept {
  }
  return vec;
 }
-
+#endif


 template <>
@@ -75,29 +84,13 @@ 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 +186,8 @@ 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;
@@ -1933,6 +1926,7 @@ bool run() {
    && using_the_parsed_json_4()
    && using_the_parsed_json_5()
 #endif
+    && simplepad()
    && using_the_parsed_json_6()
    && json_pointer_simple()
    && json_pointer_unicode()
@@ -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	d4bf0cc7ec	sync	2024-12-09 21:36:43 -05:00
Daniel Lemire	2fbbea0b15	Merge branch 'master' of github.com:simdjson/simdjson	2024-12-09 21:36:12 -05:00
Daniel Lemire	c16486f702	release candidate 3.11.2	2024-12-09 21:35:21 -05:00
zhanglistar	f615112093	Disabling memory sanitizer with parse_string (#2310 )	2024-12-09 10:20:33 -05:00
Daniel Lemire	6bbcbfbb95	version 3.11.1	2024-12-07 11:13:00 -05:00
Valery Mironov	e6578fea39	Fix missing override (#2305 )	2024-12-07 11:12:25 -05:00
Joyee Cheung	6fb050d04e	fix: fix deprecation from -Wdeprecated-literal-operator (#2307 ) Otherwise simdjson doesn't build with V8's Node.js fork, which uses -Werror,-Wdeprecated-literal-operator and latest version of clang.	2024-12-07 11:12:14 -05:00
Daniel Lemire	b4242d3b4f	release candidate (#2304 )	2024-12-05 22:05:39 -05:00
Daniel Lemire	cbfe2d4a21	Update vs17-arm-ci.yml	2024-12-02 20:24:24 -05:00
halx99	79126ca323	fix: processor checks inconsistently problem (#2299 )	2024-12-02 20:23:28 -05:00
Daniel Lemire	3f87f958d7	documentation	2024-12-02 00:06:20 -05:00
Daniel Lemire	cab383e1de	Update README.md	2024-11-30 20:43:20 -05:00
Daniel Lemire	9b314922a1	additional documentation	2024-11-08 11:53:34 -05:00
Daniel Lemire	587beae307	prevent int to pointer implicit conversion for operator[](const char *) (#2286 )	2024-11-01 18:11:43 -04:00
Daniel Lemire	f53981d945	Update dom.md	2024-11-01 12:23:35 -04:00
Daniel Lemire	41b4ffd6aa	Update basics.md	2024-11-01 12:15:40 -04:00
Daniel Lemire	6cd8a6d776	adding pad function (#2283 )	2024-10-29 21:26:01 -04:00
Daniel Lemire	3c0d032ded	Candidate for C++20 deserialization features (#2276 ) * 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 * 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> * fix: correct small issues with deserialize (#2232) * 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> * 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> * update CI on the builder_development_branch (no code change) (#2262) * typo * 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> * minor update * More documentation regarding builder (#2270) * minor update * more improvment to our documentation (builder branch) * putting back missing functions * merge candidate --------- Co-authored-by: M. Bahoosh <moisrex@gmail.com> Co-authored-by: Daniel Lemire <dlemire@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> Co-authored-by: M. Bahoosh <12122474+the-moisrex@users.noreply.github.com>	2024-10-18 20:37:38 -04:00