Merge branch 'develop' into claude/todo-191-plan-508110

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Fix links to moved API pages in the API changes page
2026-10-22 22:08:55 +00:00 · 2026-10-21 10:51:41 +02:00 · 2026-10-10 07:42:37 +02:00 · 2026-10-10 04:01:42 +02:00 · 2026-10-04 17:35:55 +02:00 · 2026-09-30 20:36:12 +02:00
177 changed files with 668257 additions and 10590 deletions
@@ -18,8 +18,7 @@ environment:
  matrix:
    # The Visual Studio 2017 jobs compile everything with /std:c++17, so they
    # only build the C++17 variant of each test, split into two jobs each to
-    # stay below AppVeyor's 60-minute limit per job. The Visual Studio 2019
-    # job builds the tests for all standards and is split for the same reason.
+    # stay below AppVeyor's 60-minute limit per job.
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
      configuration: Debug
      platform: x86
@@ -51,13 +50,7 @@ environment:
      configuration: Release
      platform: x86
      CXX_FLAGS: "/W4 /WX"
-      CMAKE_OPTIONS: "-DJSON_ImplicitConversions=OFF -DJSON_TestShard=0/2"
-      GENERATOR: Visual Studio 16 2019
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
-      configuration: Release
-      platform: x86
-      CXX_FLAGS: "/W4 /WX"
-      CMAKE_OPTIONS: "-DJSON_ImplicitConversions=OFF -DJSON_TestShard=1/2"
+      CMAKE_OPTIONS: "-DJSON_ImplicitConversions=OFF"
      GENERATOR: Visual Studio 16 2019

    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
@@ -64,7 +64,6 @@ labels:
    - "tests/src/unit-json_view.*"
    - "tests/src/json_view_test_helpers\\.hpp"
    - "tests/src/fuzzer-(parse_json_view|json_view_image)\\.cpp"
-    - "tests/benchmarks/json_view/.*"
    - "tools/amalgamate/config_json_view\\.json"
    - "docs/mkdocs/docs/features/json_view\\.md"
    - "docs/mkdocs/docs/api/basic_json_(document|view)/.*"
@@ -154,28 +154,6 @@ jobs:
          # PR content in a job without credentials.
          python3 tools/generate_natvis/generate_natvis.py $MAIN_DIR

-      - name: Check the nlohmann_json.natvis generator options
-        run: |
-          cd $MAIN_DIR
-          # The options for configurations outside the checked-in file write
-          # to a temporary file, so they do not affect the diff below.
-          GENERATOR=tools/generate_natvis/generate_natvis.py
-          python3 $GENERATOR --list-tags
-          TAG_COUNT=$(python3 $GENERATOR --list-tags | wc -l)
-
-          python3 $GENERATOR --abi-tags diag,_dp,_vns --abi-tags _diag --output $RUNNER_TEMP/abi_tags.natvis
-          grep -q '<!-- Namespace nlohmann::json_abi_diag_dp_vns -->' $RUNNER_TEMP/abi_tags.natvis
-          grep -q '<!-- Namespace nlohmann::json_abi_diag_dp_vns_v[0-9_]* -->' $RUNNER_TEMP/abi_tags.natvis
-          test $(grep -c '<!-- Namespace ' $RUNNER_TEMP/abi_tags.natvis) -eq $(( $(grep -c '<!-- Namespace ' nlohmann_json.natvis) + 2 ))
-
-          python3 $GENERATOR --all --output $RUNNER_TEMP/all.natvis
-          test $(grep -c '<!-- Namespace ' $RUNNER_TEMP/all.natvis) -eq $(( (1 << TAG_COUNT) * 2 + 1 ))
-
-          if python3 $GENERATOR --abi-tags _unknown --output $RUNNER_TEMP/unknown.natvis; then
-            echo "generate_natvis.py accepted an unknown ABI tag"
-            exit 1
-          fi
-
      - name: Build patch and check for differences
        id: diff
        run: |
@@ -0,0 +1,81 @@
+name: "Check API documentation"
+
+on:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  check_api_docs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
+        with:
+          egress-policy: audit
+
+      - name: Checkout pull request
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: Install clang
+        # Used only as a subprocess for `clang++ -E -v` system-include-path discovery in
+        # extract_api.py; it does not need to version-match the pinned libclang pip wheel
+        # below, which does the actual AST parsing. Do not "fix" this to be version-matched.
+        run: sudo apt-get update && sudo apt-get install -y clang
+
+      - name: Install Python dependencies
+        run: pip install -r tools/api_checker/requirements.txt
+
+      - name: Extract API and regenerate the committed surface file
+        run: |
+          python3 tools/api_checker/extract_api.py \
+            --header include/nlohmann/json.hpp \
+            --include include \
+            --output /tmp/api_snapshot.json \
+            --surface-output tools/api_checker/api_surface.json
+
+      - name: "Check API documentation (Phase 1: advisory)"
+        # Surfaces missing/broken @sa links without failing the job while the backlog from the
+        # initial AST-based rollout is burned down. See tools/api_checker/POLICY.md and the PR
+        # that introduced this workflow for the two-phase rollout plan.
+        continue-on-error: true
+        run: |
+          python3 tools/api_checker/check_docs.py \
+            --snapshot /tmp/api_snapshot.json
+
+      - name: Check macro documentation (advisory only)
+        # Cross-checks docs/mkdocs/docs/api/macros/ pages against #define sites. Only checks the
+        # documented-macro-still-exists direction; never blocks CI. See POLICY.md.
+        run: python3 tools/api_checker/check_macros.py
+
+      - name: Check for uncommitted API surface changes
+        id: diff
+        run: |
+          mkdir -p ${{ github.workspace }}/patch
+          git diff --patch --no-color -- tools/api_checker/api_surface.json > ${{ github.workspace }}/patch/api_surface.patch
+          if [ -s ${{ github.workspace }}/patch/api_surface.patch ]; then
+            echo "tools/api_checker/api_surface.json is out of date. Diff:"
+            cat ${{ github.workspace }}/patch/api_surface.patch
+            echo "has_diff=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "has_diff=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      # Uploaded so contributors can fix their PR with `git apply api_surface.patch`
+      # instead of installing libclang locally.
+      - name: Upload patch
+        if: steps.diff.outputs.has_diff == 'true'
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: api-surface-patch
+          path: patch/api_surface.patch
+
+      - name: Fail if API surface file is not up to date
+        # Unlike the doc-backlog check above, this is purely mechanical regeneration with no
+        # backlog to phase in -- blocking from the start, matching check_amalgamation.yml's
+        # precedent. Contributors who add/remove/rename public API must regenerate and commit
+        # tools/api_checker/api_surface.json as part of their PR.
+        if: steps.diff.outputs.has_diff == 'true'
+        run: exit 1
@@ -1,84 +0,0 @@
-name: "json_view benchmarks"
-
-# On demand only: runs the comparison of json_view with yyjson, simdjson, and
-# Boost.JSON (tests/benchmarks/json_view/compare.py) on GitHub-hosted runners,
-# for numbers from x86-64 and AArch64 Linux. It runs when started by hand, or
-# when a pull request gets the label "benchmark" (on both architectures, with
-# GCC and the default settings). Shared runners are noisy: the results show
-# where json_view stands, but published numbers need a quiet machine (see
-# tests/benchmarks/json_view/README.md).
-
-on:
-  pull_request:
-    types: [labeled]
-  workflow_dispatch:
-    inputs:
-      runner:
-        description: "Runner image"
-        type: choice
-        options:
-          - ubuntu-24.04
-          - ubuntu-24.04-arm
-        default: ubuntu-24.04
-      compiler:
-        description: "Compiler"
-        type: choice
-        options:
-          - g++
-          - clang++
-        default: g++
-      native:
-        description: "Compile for the runner's CPU (-march=native)"
-        type: boolean
-        default: false
-      rounds:
-        description: "Rounds of bench_view"
-        type: number
-        default: 30
-
-permissions:
-  contents: read
-
-concurrency:
-  # (the label is part of the group: adding an unrelated label must not cancel a running benchmark)
-  group: json-view-benchmarks-${{ github.workflow }}-${{ github.ref }}-${{ github.event.label.name }}
-  cancel-in-progress: true
-
-jobs:
-  compare:
-    if: github.event_name == 'workflow_dispatch' || github.event.label.name == 'benchmark'
-    strategy:
-      matrix:
-        runner: ${{ fromJSON(github.event_name == 'workflow_dispatch' && format('["{0}"]', inputs.runner) || '["ubuntu-24.04", "ubuntu-24.04-arm"]') }}
-    runs-on: ${{ matrix.runner }}
-    timeout-minutes: 60
-    steps:
-      - name: Harden Runner
-        uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
-        with:
-          egress-policy: audit
-
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-
-      - name: Download test data
-        run: |
-          cmake -S . -B build -DJSON_BuildTests=On
-          cmake --build build --target download_test_data
-
-      - name: Run the comparison
-        env:
-          CXX: ${{ inputs.compiler || 'g++' }}
-          CC: ${{ inputs.compiler == 'clang++' && 'clang' || 'gcc' }}
-          ROUNDS: ${{ inputs.rounds || 30 }}
-          NATIVE: ${{ inputs.native && '--native' || '' }}
-        run: python3 tests/benchmarks/json_view/compare.py --data build/test_files --download --rounds "$ROUNDS" $NATIVE
-
-      - name: Summary
-        run: cat tests/benchmarks/json_view/results/*.md >> "$GITHUB_STEP_SUMMARY"
-
-      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: json_view-benchmarks-${{ matrix.runner }}-${{ inputs.compiler || 'g++' }}
-          path: tests/benchmarks/json_view/results/
@@ -3,6 +3,7 @@
 *.gcno
 *.gcda
 .DS_Store
+__pycache__/

 /.idea
 /cmake-build-*
@@ -44,6 +45,10 @@ venv

 nlohmann_json.spdx

+# api_checker: ephemeral, location/doc-status-sensitive working file (not the committed
+# release-tracking artifact -- see tools/api_checker/api_surface.json for that)
+/tools/api_checker/api_snapshot.json
+
 # Bazel-related
 MODULE.bazel.lock

@@ -37,7 +37,6 @@ cc_library(
        "include/nlohmann/detail/input/parser.hpp",
        "include/nlohmann/detail/input/position_t.hpp",
        "include/nlohmann/detail/input/pow5_table.hpp",
-        "include/nlohmann/detail/input/simd_scan.hpp",
        "include/nlohmann/detail/input/string_scan.hpp",
        "include/nlohmann/detail/iterators/internal_iterator.hpp",
        "include/nlohmann/detail/iterators/iter_impl.hpp",
@@ -6,7 +6,6 @@ This file describes the source for supporting files; that is, files that are not
 - [GitHub](#github)
 - [REUSE](#reuse)
 - [Package Managers](#package-managers)
- [Debugging](#debugging)

 ## Continuous Integration

@@ -290,29 +289,3 @@ The module definition for [Bazel](https://bazel.build)'s [Bzlmod](https://bazel.
 Further documentation:

 - [Bazel modules](https://bazel.build/external/module)
-
-## Debugging
-
-### `nlohmann_json.natvis`
-
-The [Natvis](https://learn.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects) file that
-gives `json` values a friendly view in the Visual Studio debugger. The file is generated by
-`tools/generate_natvis/generate_natvis.py` from the template `tools/generate_natvis/nlohmann_json.natvis.j2` and the ABI
-tags and version in `include/nlohmann/detail/abi_macros.hpp`; change the script or the template rather than editing
-the file by hand. The file can be updated by calling
-
-```shell
-make natvis
-```
-
-The "Check amalgamation" workflow fails if the file is out of date.
-
-The file covers the namespace variants with up to two ABI tags. A Natvis file for other configurations can be
-generated with the `--abi-tags` or `--all` options, for example
-`make natvis NATVIS_ARGS="--abi-tags _diag,_dp,_vns --output my_nlohmann_json.natvis"`; see
-[`tools/generate_natvis`](tools/generate_natvis/README.md). With MSVC, CMake adds the file to the `nlohmann_json`
-target and installs it.
-
-Further documentation:
-
- [Create custom views of C++ objects in the debugger using the Natvis framework](https://learn.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects)
@@ -46,7 +46,7 @@ all:
 	@echo "clean - remove built files"
 	@echo "(fuzzers) - see tests/fuzzing.md, or run 'make -C tests fuzzers' to build the AFL fuzzers"
 	@echo "macro_builder_check - check that macro_scope.hpp matches tools/macro_builder's output"
-	@echo "natvis - regenerate nlohmann_json.natvis from the current ABI tags and version (pass generator options via NATVIS_ARGS, see tools/generate_natvis/README.md)"
+	@echo "natvis - regenerate nlohmann_json.natvis from the current ABI tags and version"
 	@echo "pretty - beautify code with Artistic Style"
 	@echo "pvs_studio - run the PVS-Studio static analyzer and open the report"
 	@echo "release - create the release files (include.zip, json.tar.xz, single headers, signatures, hashes)"
@@ -120,15 +120,13 @@ $(AMALGAMATED_VIEW_FILE): $(SRCS)
 	tools/amalgamate/amalgamate.py -c tools/amalgamate/config_json_view.json -s . --verbose=yes

 NATVIS_VENV=tools/generate_natvis/venv
-# extra options for generate_natvis.py, e.g. NATVIS_ARGS="--abi-tags _diag,_dp,_vns --output my.natvis"
-NATVIS_ARGS=

 # regenerate nlohmann_json.natvis from the ABI tags and version in include/nlohmann/detail/abi_macros.hpp
 # (the dependencies are installed into a virtual environment first)
 natvis:
 	@test -d $(NATVIS_VENV) || python3 -mvenv $(NATVIS_VENV)
 	@$(NATVIS_VENV)/bin/python3 -c 'import jinja2' 2>/dev/null || $(NATVIS_VENV)/bin/pip3 install --quiet -r tools/generate_natvis/requirements.txt
-	$(NATVIS_VENV)/bin/python3 tools/generate_natvis/generate_natvis.py $(NATVIS_ARGS) .
+	$(NATVIS_VENV)/bin/python3 tools/generate_natvis/generate_natvis.py .

 # regenerate the two tools/macro_builder blocks of $(MACRO_SCOPE_HPP) (see its README.md) and diff against the
 # checked-in header; phony, because it never writes $(MACRO_SCOPE_HPP) itself
@@ -105,7 +105,7 @@ Thanks everyone!

 :books: If you want to **learn more** about how to use the library, check out the rest of the [**README**](#examples), have a look at [**code examples**](https://github.com/nlohmann/json/tree/develop/docs/mkdocs/docs/examples), or browse through the [**help pages**](https://json.nlohmann.me).

-:construction: If you want to understand the **API** better, check out the [**API Reference**](https://json.nlohmann.me/api/basic_json/) or have a look at the [quick reference](#quick-reference) below.
+:construction: If you want to understand the **API** better, check out the [**API Reference**](https://json.nlohmann.me/api/basic_json/) or have a look at the [quick reference](#quick-reference) below. The public API surface is derived mechanically and checked for documentation coverage by the tooling in [`tools/api_checker/`](tools/api_checker/), whose [POLICY.md](tools/api_checker/POLICY.md) defines what counts as public API and what stability is guaranteed.

 :bug: If you found a **bug**, please check the [**FAQ**](https://json.nlohmann.me/home/faq/) if it is a known issue or the result of a design decision. Please also have a look at the [**issue list**](https://github.com/nlohmann/json/issues) before you [**create a new issue**](https://github.com/nlohmann/json/issues/new/choose). Please provide as much information as possible to help us understand and reproduce your issue.

@@ -485,8 +485,10 @@ basic_json(basic_json&& other) noexcept;
 1. Since version 1.0.0.
 2. Since version 1.0.0.
 3. Since version 2.1.0.
-4. Since version 3.2.0. Explicit for different string types if `JSON_USE_IMPLICIT_CONVERSIONS` is `0` since
-   version 3.13.0.
+4. Since version 3.2.0. Also initializes the position reported by
+   [`start_pos()`](start_pos.md)/[`end_pos()`](end_pos.md) from `val` when
+   [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) is enabled, since version 3.12.0. Explicit
+   for different string types if `JSON_USE_IMPLICIT_CONVERSIONS` is `0` since version 3.13.0.
 5. Since version 1.0.0.
 6. Since version 1.0.0.
 7. Since version 1.0.0. Fixed in version 3.13.0 to also check the iterator range for binary values; before, a range
@@ -0,0 +1,38 @@
+# <small>nlohmann::basic_json::</small>bjdata_version_t
+
+```cpp
+enum class bjdata_version_t
+{
+    draft2,
+    draft3,
+};
+```
+
+This enumeration is used in the [`to_bjdata`](to_bjdata.md) function to choose which draft version of
+the BJData specification to encode ND-array extensions for:
+
+draft2
+:   encode using the BJData Draft 2 ND-array format
+
+draft3
+:   encode using the BJData Draft 3 ND-array format
+
+## Examples
+
+??? example
+
+    The example shows how `bjdata_version_t` selects the BJData draft used by `to_bjdata`.
+
+    ```cpp
+    --8<-- "examples/bjdata_version_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/bjdata_version_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.12.0.
@@ -0,0 +1,32 @@
+# <small>nlohmann::basic_json::</small>initializer_list_t
+
+```cpp
+using initializer_list_t = std::initializer_list<detail::json_ref<basic_json>>;
+```
+
+The type used for the initializer-list [constructor](basic_json.md) (overload 5) and for functions
+such as [`operator=`](operator=.md) that accept a braced-init-list of JSON values. Each element wraps a
+`basic_json` value or something convertible to one, deferring the decision of whether the list should be
+parsed as a JSON array or a JSON object to the constructor itself.
+
+See the [constructor](basic_json.md) documentation for how `initializer_list_t` values are interpreted.
+
+## Examples
+
+??? example
+
+    The example shows how an `initializer_list_t` is used to construct a JSON value.
+
+    ```cpp
+    --8<-- "examples/initializer_list_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/initializer_list_t.output"
+    ```
+
+## Version history
+
+- Since version 1.0.0.
@@ -0,0 +1,31 @@
+# <small>nlohmann::basic_json::</small>json_sax_t
+
+```cpp
+using json_sax_t = json_sax<basic_json>;
+```
+
+The [`json_sax`](../json_sax/index.md) interface bound to this `basic_json` specialization, i.e. with
+`BasicJsonType` fixed to `basic_json`. Used as the SAX interface type by [`sax_parse`](sax_parse.md) and
+other SAX-based parsing functions.
+
+See [`nlohmann::json_sax`](../json_sax/index.md) for more information.
+
+## Examples
+
+??? example
+
+    The example shows the type `json_sax_t`.
+
+    ```cpp
+    --8<-- "examples/json_sax_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/json_sax_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.2.0.
@@ -38,7 +38,7 @@ Strong guarantee: `source` and `target` are never modified.

 Linear in the total number of values (including nested ones) in `source` and `target`, times the cost of a key-based
 object operation (looking up a key, or adding one to the patch): logarithmic for [`json`](../json.md), and linear for
-[`ordered_json`](../ordered_json.md) (see [`ordered_map` complexity](../ordered_map.md#complexity)). For
+[`ordered_json`](../ordered_json.md) (see [`ordered_map` complexity](../ordered_map/index.md#complexity)). For
 `ordered_json`, diffing two objects with `n` and `m` members therefore takes O((n+m)²).

 ## Notes
@@ -51,3 +51,5 @@ Linear.
 ## Version history

 - Added in version 1.0.0.
+- The `noexcept` specification was extended to also depend on
+  [`json_base_class_t`](json_base_class_t.md)'s move-assignment in version 3.11.3.
@@ -92,3 +92,8 @@ Linear in the size of the JSON value.
 - Since version 1.0.0.
 - Macros `JSON_EXPLICIT`/[`JSON_USE_IMPLICIT_CONVERSIONS`](../macros/json_use_implicit_conversions.md) added
  in version 3.9.0.
+- The exclusion of `std::any` from this conversion became conditional on
+  [`JSON_HAS_STATIC_RTTI`](../macros/json_has_static_rtti.md) in version 3.11.3.
+- `std::optional<T>` excluded from this conversion in version 3.13.0; use
+  [`get<std::optional<T>>()`](get.md)/[`get_to()`](get_to.md) instead (see
+  [Converting values](../../features/conversions.md)).
@@ -0,0 +1,32 @@
+# <small>nlohmann::byte_container_with_subtype::</small>container_type
+
+```cpp
+using container_type = BinaryType;
+```
+
+The type of the underlying binary container, forwarded from the `BinaryType` template parameter that
+`byte_container_with_subtype` is instantiated with. `byte_container_with_subtype` publicly inherits from
+`container_type`.
+
+See [`basic_json::binary_t`](../basic_json/binary_t.md) for the type typically used to instantiate
+`BinaryType`.
+
+## Examples
+
+??? example
+
+    The example shows the type `container_type`.
+
+    ```cpp
+    --8<-- "examples/byte_container_with_subtype__container_type.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/byte_container_with_subtype__container_type.output"
+    ```
+
+## Version history
+
+- Since version 3.8.0.
@@ -0,0 +1,28 @@
+# <small>nlohmann::byte_container_with_subtype::</small>subtype_type
+
+```cpp
+using subtype_type = std::uint64_t;
+```
+
+The type used to store the optional binary subtype tag. See [`subtype`](subtype.md) and
+[`set_subtype`](set_subtype.md).
+
+## Examples
+
+??? example
+
+    The example shows the type `subtype_type`.
+
+    ```cpp
+    --8<-- "examples/byte_container_with_subtype__subtype_type.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/byte_container_with_subtype__subtype_type.output"
+    ```
+
+## Version history
+
+- Since version 3.8.0.
@@ -0,0 +1,30 @@
+# <small>nlohmann::json_sax::</small>binary_t
+
+```cpp
+using binary_t = typename BasicJsonType::binary_t;
+```
+
+The type used by the [`binary`](binary.md) callback for JSON binary values, forwarded from the
+`BasicJsonType` template parameter.
+
+See [`basic_json::binary_t`](../basic_json/binary_t.md) for more information.
+
+## Examples
+
+??? example
+
+    The example shows the type `binary_t` and its relation to `basic_json::binary_t`.
+
+    ```cpp
+    --8<-- "examples/json_sax__binary_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/json_sax__binary_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.8.0.
@@ -0,0 +1,33 @@
+# <small>nlohmann::json_sax::</small>json_sax
+
+```cpp
+// (1)
+json_sax() = default;
+
+// (2)
+json_sax(const json_sax&) = default;
+
+// (3)
+json_sax(json_sax&&) noexcept = default;
+```
+
+1. Default constructor.
+2. Copy constructor.
+3. Move constructor.
+
+`json_sax` is a pure abstract base class with no data members of its own, so all three constructors are
+defaulted and only exist to make derived SAX consumers explicitly copyable/movable.
+
+## Exception safety
+
+No-throw guarantee: none of these constructors throw exceptions.
+
+## Complexity
+
+Constant.
+
+<!-- NOLINT Examples -->
+
+## Version history
+
+- Added in version 3.2.0.
@@ -0,0 +1,30 @@
+# <small>nlohmann::json_sax::</small>number_float_t
+
+```cpp
+using number_float_t = typename BasicJsonType::number_float_t;
+```
+
+The type used by the [`number_float`](number_float.md) callback for JSON floating-point numbers,
+forwarded from the `BasicJsonType` template parameter.
+
+See [`basic_json::number_float_t`](../basic_json/number_float_t.md) for more information.
+
+## Examples
+
+??? example
+
+    The example shows the type `number_float_t` and its relation to `basic_json::number_float_t`.
+
+    ```cpp
+    --8<-- "examples/json_sax__number_float_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/json_sax__number_float_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.2.0.
@@ -0,0 +1,30 @@
+# <small>nlohmann::json_sax::</small>number_integer_t
+
+```cpp
+using number_integer_t = typename BasicJsonType::number_integer_t;
+```
+
+The type used by the [`number_integer`](number_integer.md) callback for JSON integer numbers, forwarded
+from the `BasicJsonType` template parameter.
+
+See [`basic_json::number_integer_t`](../basic_json/number_integer_t.md) for more information.
+
+## Examples
+
+??? example
+
+    The example shows the type `number_integer_t` and its relation to `basic_json::number_integer_t`.
+
+    ```cpp
+    --8<-- "examples/json_sax__number_integer_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/json_sax__number_integer_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.2.0.
@@ -0,0 +1,30 @@
+# <small>nlohmann::json_sax::</small>number_unsigned_t
+
+```cpp
+using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+```
+
+The type used by the [`number_unsigned`](number_unsigned.md) callback for JSON unsigned integer numbers,
+forwarded from the `BasicJsonType` template parameter.
+
+See [`basic_json::number_unsigned_t`](../basic_json/number_unsigned_t.md) for more information.
+
+## Examples
+
+??? example
+
+    The example shows the type `number_unsigned_t` and its relation to `basic_json::number_unsigned_t`.
+
+    ```cpp
+    --8<-- "examples/json_sax__number_unsigned_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/json_sax__number_unsigned_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.2.0.
@@ -0,0 +1,29 @@
+# <small>nlohmann::json_sax::</small>operator=
+
+```cpp
+// (1)
+json_sax& operator=(const json_sax&) = default;
+
+// (2)
+json_sax& operator=(json_sax&&) noexcept = default;
+```
+
+1. Copy assignment operator.
+2. Move assignment operator.
+
+`json_sax` is a pure abstract base class with no data members of its own, so both assignment operators
+are defaulted and only exist to make derived SAX consumers explicitly copy-/move-assignable.
+
+## Exception safety
+
+No-throw guarantee: neither operator throws exceptions.
+
+## Complexity
+
+Constant.
+
+<!-- NOLINT Examples -->
+
+## Version history
+
+- Added in version 3.2.0.
@@ -0,0 +1,30 @@
+# <small>nlohmann::json_sax::</small>string_t
+
+```cpp
+using string_t = typename BasicJsonType::string_t;
+```
+
+The type used by the [`string`](string.md) and [`key`](key.md) callbacks for JSON strings and object
+keys, forwarded from the `BasicJsonType` template parameter.
+
+See [`basic_json::string_t`](../basic_json/string_t.md) for more information.
+
+## Examples
+
+??? example
+
+    The example shows the type `string_t` and its relation to `basic_json::string_t`.
+
+    ```cpp
+    --8<-- "examples/json_sax__string_t.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/json_sax__string_t.output"
+    ```
+
+## Version history
+
+- Added in version 3.2.0.
@@ -0,0 +1,22 @@
+# <small>nlohmann::json_sax::</small>~json_sax
+
+```cpp
+virtual ~json_sax() = default;
+```
+
+Destructor. Virtual to allow proper destruction of derived SAX consumer classes through a
+pointer/reference to `json_sax`.
+
+## Exception safety
+
+No-throw guarantee: this destructor never throws exceptions.
+
+## Complexity
+
+Constant.
+
+<!-- NOLINT Examples -->
+
+## Version history
+
+- Added in version 3.2.0.
@@ -38,7 +38,6 @@ header. See also the [macro overview page](../../features/macros.md).
 - [**JSON_HAS_THREE_WAY_COMPARISON**](json_has_three_way_comparison.md) - control 3-way comparison support
 - [**JSON_NO_AUTOMATIC_UDLS**](json_no_automatic_udls.md) - do not include the user-defined string literals (UDLs) automatically
 - [**JSON_NO_IO**](json_no_io.md) - switch off functions relying on certain C++ I/O headers
- [**JSON_NO_SIMD**](json_no_simd.md) - use only portable code instead of vector instructions (SSE2, SSSE3, NEON)
 - [**JSON_NO_THREAD_LOCAL**](json_no_thread_local.md) - switch off the use of `thread_local` storage
 - [**JSON_SKIP_UNSUPPORTED_COMPILER_CHECK**](json_skip_unsupported_compiler_check.md) - do not warn about unsupported compilers
 - [**JSON_USE_GLOBAL_UDLS**](json_use_global_udls.md) - place user-defined string literals (UDLs) into the global namespace
@@ -1,83 +0,0 @@
-# JSON_NO_SIMD
-
-```cpp
-#define JSON_NO_SIMD
-```
-
-When defined, the library uses only portable C++ code where it would otherwise use vector instructions: when scanning
-strings during parsing, and when writing floating-point numbers during serialization.
-
-The macro is an escape hatch, for example for toolchains that cannot compile the vector code, for sanitizers or
-analyzers that do not understand it, or to compare the speed of both variants. It does not change any result: values,
-exceptions, and error positions are the same either way. Only the speed differs.
-
-## Default definition
-
-By default, `#!cpp JSON_NO_SIMD` is not defined, and vector instructions are used where the target has them.
-
-```cpp
-#undef JSON_NO_SIMD
-```
-
-## Notes
-
-!!! note "Which instructions are used"
-
-    - **x86-64:** SSE2, which every x86-64 CPU has, finds the end of runs of plain string characters 16 bytes at a time
-      and writes the digits of floating-point numbers. The UTF-8 check of non-ASCII text needs SSSE3, which is not part
-      of x86-64: it is compiled for SSSE3 with a function attribute and used when the CPU has SSSE3 (every x86-64 CPU
-      since about 2011), else the portable check. Code compiled for SSSE3 anyway (e.g., with `-mssse3` or `-march=native`)
-      skips this check of the CPU. 32-bit x86 uses SSE2 for strings when the compiler targets it.
-    - **AArch64:** NEON, which every 64-bit Arm CPU has, checks UTF-8 text and long runs of plain string characters 16
-      bytes at a time, and writes the digits of floating-point numbers. With MSVC, only the floating-point digits use
-      NEON.
-    - **Other targets:** portable code only.
-
-    Strings are only scanned this way for contiguous input and for the characters a `#!cpp std::istream` holds in its
-    stream buffer (see [`JSON_DISABLE_STREAM_BULK_SCAN`](json_disable_stream_bulk_scan.md)); other inputs are read one
-    character at a time.
-
-!!! note "Interaction with `JSON_USE_SIMDUTF`"
-
-    With [`JSON_USE_SIMDUTF`](json_use_simdutf.md), runs of string characters are first validated by simdutf; the code
-    described here is used for what simdutf does not accept, so that errors are reported at the same position.
-    `JSON_NO_SIMD` does not affect simdutf.
-
-!!! note "ABI compatibility"
-
-    The macro selects between two definitions of the library's internal scanning and formatting functions. Whether it
-    is defined is encoded in the [namespace](../../features/namespace.md) (tag `_ns`), resulting in distinct symbol
-    names. Translation units compiled with and without it can therefore be linked into the same program without One
-    Definition Rule (ODR) violations, but they cannot exchange instances of library types.
-
-## Examples
-
-??? example "Example: switching off vector instructions"
-
-    The program parses and serializes the same values with and without the macro:
-
-    ```cpp
-    #define JSON_NO_SIMD
-    #include <iostream>
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        const json j = json::parse(R"({"name": "日本語 text", "pi": 3.141592653589793})");
-        std::cout << j.dump() << '\n';  // {"name":"日本語 text","pi":3.141592653589793}
-    }
-    ```
-
-## See also
-
- [**parse**](../basic_json/parse.md) - deserialize from a compatible input
- [**dump**](../basic_json/dump.md) - serialization
- [**JSON_USE_SIMDUTF**](json_use_simdutf.md) - use the simdutf library to accelerate UTF-8 validation
- [**JSON_DISABLE_STREAM_BULK_SCAN**](json_disable_stream_bulk_scan.md) - read a `std::istream` one character at a time
- [Parsing: input sources and performance](../../features/parsing/index.md#input-sources-and-performance)
-
-## Version history
-
- Added in version 3.13.0.
@@ -6,9 +6,8 @@

 When defined, the parser validates the UTF-8 content of JSON strings that come from a **contiguous byte input**
 (`std::string`, `std::vector<char>`/`<std::uint8_t>`, string literals, `const char*` ranges, …) using the
-[simdutf](https://github.com/simdutf/simdutf) library instead of the built-in validator (which uses SSSE3 or NEON where
-available, see [`JSON_NO_SIMD`](json_no_simd.md)). On text with many non-ASCII characters (e.g. CJK or emoji) this can
-validate faster, depending on the CPU.
+[simdutf](https://github.com/simdutf/simdutf) library instead of the built-in scalar validator. On text with many
+non-ASCII characters (e.g. CJK or emoji) this can validate several times faster.

 This is an **opt-in external dependency**. The library itself remains header-only and its behavior is unchanged: the
 same input is accepted or rejected either way, and every parse error is reported at the same position with the same
@@ -39,6 +39,6 @@ the library.
 ## Version history

 - Added in version 3.11.0. Changed inline namespace name in version 3.11.2. Added the ABI tag `_dp` in
-  version 3.12.0, and the ABI tags `_bics`, `_psp`, `_snul`, `_sbu8`, `_ekmo`, `_dsbs`, `_dufio`, `_ns`, `_vns`,
-  and `_vssse3` in version 3.13.0; see
+  version 3.12.0, and the ABI tags `_bics`, `_psp`, `_snul`, `_sbu8`, `_ekmo`, `_dsbs`, `_dufio`, `_vns`, and
+  `_vssse3` in version 3.13.0; see
  [`nlohmann` Namespace](../../features/namespace.md#structure).
@@ -8,16 +8,16 @@ This type preserves the insertion order of object keys.

 ## Iterator invalidation

-The type is based on [`ordered_map`](ordered_map.md) which in turn uses a `std::vector` to store object elements.
+The type is based on [`ordered_map`](ordered_map/index.md) which in turn uses a `std::vector` to store object elements.
 Therefore, adding object elements can yield a reallocation in which case all iterators (including the
 [`end()`](basic_json/end.md) iterator) and all references to the elements are invalidated. Also, any iterator or
 reference after the insertion point will point to the same index, which is now a different value.

 ## Complexity

-[`ordered_map`](ordered_map.md) has no lookup index: every key-based object operation is a linear scan, so building or
+[`ordered_map`](ordered_map/index.md) has no lookup index: every key-based object operation is a linear scan, so building or
 parsing an object of `n` keys costs O(n²) rather than O(n log n). See
-[`ordered_map` complexity](ordered_map.md#complexity) for the per-operation table and for measured numbers.
+[`ordered_map` complexity](ordered_map/index.md#complexity) for the per-operation table and for measured numbers.

 ## Examples

@@ -37,7 +37,7 @@ parsing an object of `n` keys costs O(n²) rather than O(n log n). See

 ## See also

- [ordered_map](ordered_map.md)
+- [ordered_map](ordered_map/index.md)
 - [Object Order](../features/object_order.md)

 ## Version history
@@ -0,0 +1,28 @@
+# <small>nlohmann::ordered_map::</small>Container
+
+```cpp
+using Container = std::vector<std::pair<const Key, T>, Allocator>;
+```
+
+The base container type that `ordered_map` publicly inherits from. Elements are stored in insertion
+order as `#!cpp std::pair<const Key, T>` entries in a `std::vector`.
+
+## Examples
+
+??? example
+
+    The example shows the type `Container`.
+
+    ```cpp
+    --8<-- "examples/ordered_map__Container.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__Container.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,61 @@
+# <small>nlohmann::ordered_map::</small>at
+
+```cpp
+// (1)
+T& at(const key_type& key);
+const T& at(const key_type& key) const;
+
+// (2)
+template<class KeyType>
+T& at(KeyType&& key);
+template<class KeyType>
+const T& at(KeyType&& key) const;
+```
+
+1. Returns a reference to the value mapped to `key`.
+2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
+   (heterogeneous lookup, e.g. looking up by a `#!cpp const char*` without constructing a temporary
+   `key_type`). Only participates in overload resolution if `KeyType` is usable as a key type.
+
+## Template parameters
+
+`KeyType`
+:   a type comparable to `key_type` via [`key_compare`](key_compare.md)
+
+## Parameters
+
+`key` (in)
+:   key of the element to find
+
+## Return value
+
+reference to the mapped value of the element with key equal to `key`
+
+## Exceptions
+
+Throws `std::out_of_range` if no element with key `key` exists.
+
+## Complexity
+
+Linear in the number of elements.
+
+## Examples
+
+??? example
+
+    The example shows how `at` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__at.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__at.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+- Overload (2) added in version 3.11.0.
@@ -0,0 +1,53 @@
+# <small>nlohmann::ordered_map::</small>count
+
+```cpp
+// (1)
+size_type count(const key_type& key) const;
+
+// (2)
+template<class KeyType>
+size_type count(KeyType&& key) const;
+```
+
+1. Returns the number of elements with key equal to `key` (0 or 1, since keys are unique).
+2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
+   (heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
+
+## Template parameters
+
+`KeyType`
+:   a type comparable to `key_type` via [`key_compare`](key_compare.md)
+
+## Parameters
+
+`key` (in)
+:   key of the elements to count
+
+## Return value
+
+number of elements with key equal to `key` (0 or 1)
+
+## Complexity
+
+Linear in the number of elements.
+
+## Examples
+
+??? example
+
+    The example shows how `count` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__count.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__count.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+- Overload (2) added in version 3.11.0.
@@ -0,0 +1,58 @@
+# <small>nlohmann::ordered_map::</small>emplace
+
+```cpp
+// (1)
+std::pair<iterator, bool> emplace(const key_type& key, T&& t);
+
+// (2)
+template<class KeyType>
+std::pair<iterator, bool> emplace(KeyType&& key, T&& t);
+```
+
+1. Inserts `#!cpp {key, t}` if no element with an equal key already exists (per [`key_compare`](key_compare.md)),
+   appending it at the end to preserve insertion order. If an equal key already exists, does nothing.
+2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
+   (heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
+
+## Template parameters
+
+`KeyType`
+:   a type comparable to `key_type` via [`key_compare`](key_compare.md)
+
+## Parameters
+
+`key` (in)
+:   key of the element to insert
+
+`t` (in)
+:   value of the element to insert
+
+## Return value
+
+pair of an iterator to the (possibly newly inserted) element, and a `bool` that is `true` if insertion
+took place and `false` if an element with an equal key already existed
+
+## Complexity
+
+Linear in the number of elements.
+
+## Examples
+
+??? example
+
+    The example shows how `emplace` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__emplace.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__emplace.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+- Overload (2) added in version 3.11.0.
@@ -0,0 +1,75 @@
+# <small>nlohmann::ordered_map::</small>erase
+
+```cpp
+// (1)
+size_type erase(const key_type& key);
+
+// (2)
+template<class KeyType>
+size_type erase(KeyType&& key);
+
+// (3)
+iterator erase(iterator pos);
+
+// (4)
+iterator erase(iterator first, iterator last);
+```
+
+1. Removes the element with key equal to `key`, if any, preserving the relative order of the remaining
+   elements.
+2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
+   (heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
+3. Removes the element at `pos`.
+4. Removes the elements in range `[first, last)`.
+
+## Template parameters
+
+`KeyType`
+:   a type comparable to `key_type` via [`key_compare`](key_compare.md)
+
+## Parameters
+
+`key` (in)
+:   key of the element to remove
+
+`pos` (in)
+:   iterator to the element to remove
+
+`first` (in)
+:   iterator to the first element to remove
+
+`last` (in)
+:   iterator one past the last element to remove
+
+## Return value
+
+1. number of elements removed (0 or 1)
+2. number of elements removed (0 or 1)
+3. iterator following the removed element
+4. iterator following the last removed element
+
+## Complexity
+
+Linear in the number of elements (elements after the removed one(s) are shifted to keep storage
+contiguous).
+
+## Examples
+
+??? example
+
+    The example shows how `erase` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__erase.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__erase.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+- Overload (2) added in version 3.11.0.
@@ -0,0 +1,56 @@
+# <small>nlohmann::ordered_map::</small>find
+
+```cpp
+// (1)
+iterator find(const key_type& key);
+const_iterator find(const key_type& key) const;
+
+// (2)
+template<class KeyType>
+iterator find(KeyType&& key);
+template<class KeyType>
+const_iterator find(KeyType&& key) const;
+```
+
+1. Returns an iterator to the element with key equal to `key`, or `end()` if no such element exists.
+2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
+   (heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
+
+## Template parameters
+
+`KeyType`
+:   a type comparable to `key_type` via [`key_compare`](key_compare.md)
+
+## Parameters
+
+`key` (in)
+:   key of the element to find
+
+## Return value
+
+iterator to the element with key equal to `key`, or `end()` if not found
+
+## Complexity
+
+Linear in the number of elements.
+
+## Examples
+
+??? example
+
+    The example shows how `find` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__find.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__find.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+- Overload (2) added in version 3.11.0.
@@ -6,7 +6,7 @@ template<class Key, class T, class IgnoredLess = std::less<Key>,
 struct ordered_map : std::vector<std::pair<const Key, T>, Allocator>;
 ```

-A minimal map-like container that preserves insertion order for use within [`nlohmann::ordered_json`](ordered_json.md)
+A minimal map-like container that preserves insertion order for use within [`nlohmann::ordered_json`](../ordered_json.md)
 (`nlohmann::basic_json<ordered_map>`).

 ## Template parameters
@@ -30,19 +30,19 @@ case all iterators (including the `end()` iterator) and all references to the el

 When the storage grows, the keys are copied and the mapped values are moved to the new storage. A plain `std::vector`
 would copy the whole elements instead, because their `#!cpp const` keys make them not nothrow move constructible; for
-[`ordered_json`](ordered_json.md), this would be a deep copy of every nested value. The values are only copied if
+[`ordered_json`](../ordered_json.md), this would be a deep copy of every nested value. The values are only copied if
 `T` is not default constructible or not nothrow move assignable.

 ## Member types

 - **key_type** - key type (`Key`)
 - **mapped_type** - mapped type (`T`)
- **Container** - base container type (`#!cpp std::vector<std::pair<const Key, T>, Allocator>`)
+- [**Container**](Container.md) - base container type (`#!cpp std::vector<std::pair<const Key, T>, Allocator>`)
 - **iterator**
 - **const_iterator**
 - **size_type**
 - **value_type**
- **key_compare** - key comparison function
+- [**key_compare**](key_compare.md) - key comparison function
 ```cpp
 std::equal_to<Key>  // until C++14

@@ -51,15 +51,16 @@ std::equal_to<>     // since C++14

 ## Member functions

- (constructor)
- (destructor)
- **emplace**
- **operator\[\]**
- **at**
- **erase**
- **count**
- **find**
- **insert**
+- [(constructor)](ordered_map.md)
+- [(destructor)](~ordered_map.md)
+- [**operator=**](operator=.md)
+- [**emplace**](emplace.md)
+- [**operator\[\]**](operator[].md)
+- [**at**](at.md)
+- [**erase**](erase.md)
+- [**count**](count.md)
+- [**find**](find.md)
+- [**insert**](insert.md)

 ## Exception safety

@@ -89,7 +90,7 @@ This differs from `#!cpp std::map`, where the same operations are O(log n).
 !!! warning "Quadratic cost of building large objects"

    Because every insertion scans all elements inserted so far, building an object of `n` distinct keys costs
-    **O(n²)** in total. This applies to filling an [`ordered_json`](ordered_json.md) object key by key as well as to
+    **O(n²)** in total. This applies to filling an [`ordered_json`](../ordered_json.md) object key by key as well as to
    parsing one, since the parser inserts each key as it is read.

    The cost is negligible for the object sizes typically found in configuration files or API payloads, but it grows
@@ -106,7 +107,7 @@ This differs from `#!cpp std::map`, where the same operations are O(log n).
    If key order matters for objects of that size, consider a container with a lookup index, such as
    [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map)
    ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)), as the object type -- see
-    [object order](../features/object_order.md).
+    [object order](../../features/object_order.md).

 ## Examples

@@ -126,10 +127,10 @@ This differs from `#!cpp std::map`, where the same operations are O(log n).

 ## See also

- [ordered_json](ordered_json.md)
+- [ordered_json](../ordered_json.md)

 ## Version history

- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](ordered_json.md).
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
 - Added **key_compare** member in version 3.11.0.
 - Changed in version 3.13.0: growing the storage moves the mapped values instead of copying them.
@@ -0,0 +1,63 @@
+# <small>nlohmann::ordered_map::</small>insert
+
+```cpp
+// (1)
+std::pair<iterator, bool> insert(value_type&& value);
+std::pair<iterator, bool> insert(const value_type& value);
+
+// (2)
+template<typename InputIt>
+void insert(InputIt first, InputIt last);
+```
+
+1. Inserts `value` if no element with an equal key already exists (per [`key_compare`](key_compare.md)),
+   appending it at the end to preserve insertion order. If an equal key already exists, does nothing.
+2. Inserts the elements from range `[first, last)`, in iteration order, applying the same equal-key rule
+   as (1) to each element.
+
+## Template parameters
+
+`InputIt`
+:   an input iterator type
+
+## Parameters
+
+`value` (in)
+:   value to insert
+
+`first` (in)
+:   iterator to the first element to insert
+
+`last` (in)
+:   iterator one past the last element to insert
+
+## Return value
+
+1. pair of an iterator to the (possibly newly inserted) element, and a `bool` that is `true` if insertion
+   took place and `false` if an element with an equal key already existed
+2. (none)
+
+## Complexity
+
+1. Linear in the number of elements.
+2. Linear in the distance between `first` and `last`, times linear in the number of elements.
+
+## Examples
+
+??? example
+
+    The example shows how `insert` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__insert.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__insert.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,34 @@
+# <small>nlohmann::ordered_map::</small>key_compare
+
+```cpp
+using key_compare = std::equal_to<Key>;  // until C++14
+
+using key_compare = std::equal_to<>;     // since C++14
+```
+
+The comparator used to determine key equality when looking up elements. Unlike `std::map`, `ordered_map`
+uses linear search with `key_compare` rather than an ordering relation, since element order reflects
+insertion order rather than key order.
+
+Since C++14, the transparent `#!cpp std::equal_to<>` is used, which enables heterogeneous lookup (e.g.
+looking up by a `#!cpp const char*` key without constructing a temporary `Key`).
+
+## Examples
+
+??? example
+
+    The example shows how `key_compare` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__key_compare.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__key_compare.output"
+    ```
+
+## Version history
+
+- Added in version 3.11.0.
@@ -0,0 +1,32 @@
+# <small>nlohmann::ordered_map::</small>operator=
+
+```cpp
+// (1)
+ordered_map& operator=(const ordered_map& other);
+
+// (2)
+ordered_map& operator=(ordered_map&& other) noexcept(std::is_nothrow_move_assignable<Container>::value);
+```
+
+1. Copy assignment operator.
+2. Move assignment operator.
+
+## Parameters
+
+`other` (in)
+:   value to assign from
+
+## Return value
+
+`*this`
+
+## Complexity
+
+1. Linear in the size of `other`.
+2. Constant.
+
+<!-- NOLINT Examples -->
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,62 @@
+# <small>nlohmann::ordered_map::</small>operator[]
+
+```cpp
+// (1)
+T& operator[](const key_type& key);
+const T& operator[](const key_type& key) const;
+
+// (2)
+template<class KeyType>
+T& operator[](KeyType&& key);
+template<class KeyType>
+const T& operator[](KeyType&& key) const;
+```
+
+1. Returns a reference to the value mapped to `key`, inserting a default-constructed `T` (non-`const`
+   overload only) if no such element exists yet.
+2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
+   (heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
+
+## Template parameters
+
+`KeyType`
+:   a type comparable to `key_type` via [`key_compare`](key_compare.md)
+
+## Parameters
+
+`key` (in)
+:   key of the element to find or insert
+
+## Return value
+
+reference to the mapped value of the element with key equal to `key`
+
+## Exceptions
+
+The `const` overloads throw `std::out_of_range` if no element with key `key` exists (they delegate to
+[`at`](at.md)).
+
+## Complexity
+
+Linear in the number of elements.
+
+## Examples
+
+??? example
+
+    The example shows how `operator[]` is used.
+
+    ```cpp
+    --8<-- "examples/ordered_map__operator_idx.cpp"
+    ```
+
+    Output:
+
+    ```
+    --8<-- "examples/ordered_map__operator_idx.output"
+    ```
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+- Overload (2) added in version 3.11.0.
@@ -0,0 +1,66 @@
+# <small>nlohmann::ordered_map::</small>ordered_map
+
+```cpp
+// (1)
+ordered_map() noexcept(noexcept(Container()));
+
+// (2)
+explicit ordered_map(const Allocator& alloc) noexcept(noexcept(Container(alloc)));
+
+// (3)
+template <class It>
+ordered_map(It first, It last, const Allocator& alloc = Allocator());
+
+// (4)
+ordered_map(std::initializer_list<value_type> init, const Allocator& alloc = Allocator());
+
+// (5)
+ordered_map(const ordered_map&) = default;
+
+// (6)
+ordered_map(ordered_map&&) noexcept(std::is_nothrow_move_constructible<Container>::value) = default;
+```
+
+1. Default constructor. Creates an empty `ordered_map`.
+2. Creates an empty `ordered_map` using the given allocator.
+3. Creates an `ordered_map` from the elements in range `[first, last)`, inserted in iteration order.
+4. Creates an `ordered_map` from an initializer list of key/value pairs, inserted in list order.
+5. Copy constructor.
+6. Move constructor.
+
+These constructors are declared explicitly (rather than inherited via `#!cpp using Container::Container`)
+because older compilers (GCC <= 5.5, Xcode <= 9.4) do not handle the inherited constructors correctly.
+
+## Template parameters
+
+`It`
+:   an input iterator type
+
+## Parameters
+
+`alloc` (in)
+:   allocator to use for the underlying container
+
+`first` (in)
+:   iterator to the first element to insert
+
+`last` (in)
+:   iterator one past the last element to insert
+
+`init` (in)
+:   initializer list of key/value pairs to insert
+
+## Complexity
+
+1. Constant.
+2. Constant.
+3. Linear in the distance between `first` and `last`.
+4. Linear in the size of `init`.
+5. Linear in the size of `other`.
+6. Constant.
+
+<!-- NOLINT Examples -->
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,17 @@
+# <small>nlohmann::ordered_map::</small>~ordered_map
+
+```cpp
+~ordered_map() = default;
+```
+
+Destroys the `ordered_map` and frees all allocated memory.
+
+## Complexity
+
+Linear in the number of elements.
+
+<!-- NOLINT Examples -->
+
+## Version history
+
+- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,21 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // an empty binary value is encoded differently by the two drafts:
+    // draft2 omits the optimized type marker for an empty byte array,
+    // while draft3 always writes it
+    json j = json::binary({});
+
+    // encode using BJData draft2 (the default)
+    auto v_draft2 = json::to_bjdata(j, true, true, json::bjdata_version_t::draft2);
+
+    // encode using BJData draft3
+    auto v_draft3 = json::to_bjdata(j, true, true, json::bjdata_version_t::draft3);
+
+    std::cout << "draft2 size: " << v_draft2.size() << '\n'
+              << "draft3 size: " << v_draft3.size() << std::endl;
+}
@@ -0,0 +1,2 @@
+draft2 size: 4
+draft3 size: 6
@@ -0,0 +1,11 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using byte_container_with_subtype = nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>>;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<byte_container_with_subtype::container_type, std::vector<std::uint8_t>>::value
+              << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using byte_container_with_subtype = nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>>;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<byte_container_with_subtype::subtype_type, std::uint64_t>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,13 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // an initializer_list_t is what a braced-init-list of JSON values is deduced as
+    json::initializer_list_t init = {"a", 1, 2.0, false};
+
+    json j(init);
+    std::cout << j.dump() << std::endl;
+}
@@ -0,0 +1 @@
+["a",1,2.0,false]
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<json::json_sax_t::binary_t, json::binary_t>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<json::json_sax_t::number_float_t, json::number_float_t>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<json::json_sax_t::number_integer_t, json::number_integer_t>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<json::json_sax_t::number_unsigned_t, json::number_unsigned_t>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<json::json_sax_t::string_t, json::string_t>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    std::cout << std::boolalpha
+              << std::is_same<json::json_sax_t, nlohmann::json_sax<json>>::value << std::endl;
+}
@@ -0,0 +1 @@
+true
@@ -0,0 +1,12 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    using Map = nlohmann::ordered_map<std::string, int>;
+
+    std::cout << std::boolalpha
+              << "Container is std::vector<std::pair<const Key, T>>: "
+              << std::is_same<Map::Container, std::vector<std::pair<const std::string, int>>>::value
+              << std::endl;
+}
@@ -0,0 +1 @@
+Container is std::vector<std::pair<const Key, T>>: true
@@ -0,0 +1,26 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, int> m;
+    m["one"] = 1;
+    m["two"] = 2;
+
+    // access an existing element
+    std::cout << "m.at(\"one\") = " << m.at("one") << std::endl;
+
+    // modify through the reference returned by at()
+    m.at("two") = 22;
+    std::cout << "m.at(\"two\") = " << m.at("two") << std::endl;
+
+    // accessing a missing key throws
+    try
+    {
+        m.at("three");
+    }
+    catch (const std::out_of_range& e)
+    {
+        std::cout << "exception: " << e.what() << std::endl;
+    }
+}
@@ -0,0 +1,3 @@
+m.at("one") = 1
+m.at("two") = 22
+exception: key not found
@@ -0,0 +1,12 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, int> m;
+    m["one"] = 1;
+
+    std::cout << std::boolalpha
+              << "m.count(\"one\") = " << m.count("one") << '\n'
+              << "m.count(\"two\") = " << m.count("two") << std::endl;
+}
@@ -0,0 +1,2 @@
+m.count("one") = 1
+m.count("two") = 0
@@ -0,0 +1,15 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, std::string> m;
+
+    // emplace a new element
+    auto res1 = m.emplace("one", "eins");
+    std::cout << std::boolalpha << "inserted: " << res1.second << ", value: " << res1.first->second << std::endl;
+
+    // emplace with an already-existing key: no-op, returns the existing element
+    auto res2 = m.emplace("one", "uno");
+    std::cout << std::boolalpha << "inserted: " << res2.second << ", value: " << res2.first->second << std::endl;
+}
@@ -0,0 +1,2 @@
+inserted: true, value: eins
+inserted: false, value: eins
@@ -0,0 +1,24 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, int> m;
+    m["one"] = 1;
+    m["two"] = 2;
+    m["three"] = 3;
+
+    // erase by key
+    std::size_t removed = m.erase("two");
+    std::cout << "removed by key: " << removed << std::endl;
+
+    // erase by iterator
+    m.erase(m.begin());
+
+    std::cout << "remaining: ";
+    for (const auto& element : m)
+    {
+        std::cout << element.first << ' ';
+    }
+    std::cout << std::endl;
+}
@@ -0,0 +1,2 @@
+removed by key: 1
+remaining: three 
@@ -0,0 +1,19 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, int> m;
+    m["one"] = 1;
+
+    auto it = m.find("one");
+    if (it != m.end())
+    {
+        std::cout << "found: " << it->first << " = " << it->second << std::endl;
+    }
+
+    if (m.find("two") == m.end())
+    {
+        std::cout << "\"two\" not found" << std::endl;
+    }
+}
@@ -0,0 +1,2 @@
+found: one = 1
+"two" not found
@@ -0,0 +1,21 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, int> m;
+
+    // insert a single value
+    auto res = m.insert({"one", 1});
+    std::cout << std::boolalpha << "inserted: " << res.second << std::endl;
+
+    // insert a range from another container
+    std::vector<std::pair<const std::string, int>> more = {{"two", 2}, {"three", 3}};
+    m.insert(more.begin(), more.end());
+
+    for (const auto& element : m)
+    {
+        std::cout << element.first << ':' << element.second << ' ';
+    }
+    std::cout << std::endl;
+}
@@ -0,0 +1,2 @@
+inserted: true
+one:1 two:2 three:3 
@@ -0,0 +1,12 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    using Map = nlohmann::ordered_map<std::string, int>;
+    Map::key_compare compare{};
+
+    std::cout << std::boolalpha
+              << "compare(\"a\", \"a\") = " << compare("a", "a") << '\n'
+              << "compare(\"a\", \"b\") = " << compare("a", "b") << std::endl;
+}
@@ -0,0 +1,2 @@
+compare("a", "a") = true
+compare("a", "b") = false
@@ -0,0 +1,14 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+int main()
+{
+    nlohmann::ordered_map<std::string, int> m;
+
+    // operator[] inserts a default-constructed value if the key doesn't exist yet
+    m["one"] = 1;
+    std::cout << "m[\"one\"] = " << m["one"] << std::endl;
+
+    // accessing again just returns the existing value
+    std::cout << "m[\"one\"] = " << m["one"] << std::endl;
+}
@@ -0,0 +1,2 @@
+m["one"] = 1
+m["one"] = 1
@@ -174,13 +174,6 @@ security reasons (e.g., Intel Software Guard Extensions (SGX)).

 See [full documentation of `JSON_NO_IO`](../api/macros/json_no_io.md).

-## `JSON_NO_SIMD`
-
-When defined, the library uses only portable code instead of vector instructions (SSE2, SSSE3, NEON) for scanning
-strings and writing floating-point numbers. Results are the same either way. It is not defined by default.
-
-See [full documentation of `JSON_NO_SIMD`](../api/macros/json_no_simd.md).
-
 ## `JSON_NO_THREAD_LOCAL`

 When defined, the library does not use `#!cpp thread_local` storage. Copying a value and comparing two values then
@@ -27,7 +27,6 @@ The complete default namespace name is derived as follows:
      `_dsbs`.
    - [`JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md) defined non-zero appends
      `_dufio`.
-    - [`JSON_NO_SIMD`](../api/macros/json_no_simd.md) defined appends `_ns`.
    - [`JSON_VIEW_NO_SIMD`](../api/macros/json_view_no_simd.md) defined appends `_vns`.
    - [`JSON_VIEW_USE_SSSE3`](../api/macros/json_view_use_ssse3.md) defined appends `_vssse3`.
 - The inline namespace ends with the suffix `_v` followed by the 3 components of the version number separated by
@@ -115,7 +114,6 @@ follows:
  ([`JSON_STRICT_BINARY_UTF8`](../api/macros/json_strict_binary_utf8.md)), `_ekmo`
  ([`JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS`](../api/macros/json_use_objects_for_enum_keyed_maps.md)), `_dsbs`
  ([`JSON_DISABLE_STREAM_BULK_SCAN`](../api/macros/json_disable_stream_bulk_scan.md)), `_dufio`
-  ([`JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md)), `_ns`
-  ([`JSON_NO_SIMD`](../api/macros/json_no_simd.md)), `_vns`
+  ([`JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md)), `_vns`
  ([`JSON_VIEW_NO_SIMD`](../api/macros/json_view_no_simd.md)), and `_vssse3`
  ([`JSON_VIEW_USE_SSSE3`](../api/macros/json_view_use_ssse3.md)) in version 3.13.0.
@@ -51,16 +51,16 @@ If you do want to preserve the **insertion order**, you can use the type [`nlohm
    --8<-- "examples/ordered_json.output"
    ```

-Alternatively, [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) also preserves the insertion order and, unlike [`ordered_map`](../api/ordered_map.md), keeps a lookup index, so it does not have the quadratic cost described below. It is used through a small adapter ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)).
+Alternatively, [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) also preserves the insertion order and, unlike [`ordered_map`](../api/ordered_map/index.md), keeps a lookup index, so it does not have the quadratic cost described below. It is used through a small adapter ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)).

 If the order does not matter and you only want faster lookup, `boost::unordered_flat_map`, `absl::flat_hash_map`, `absl::node_hash_map`, and several other hash maps work through an adapter that restores the template argument order `basic_json` expects; see [Template Parameter Requirements](types/template_parameters.md#objecttype). Note these are *unordered*, not insertion-ordered.

 [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) cannot be used: its iterators expose the mapped value as `const`, while `basic_json` needs to modify it in place.

-The [`ordered_map`](../api/ordered_map.md) behind `nlohmann::ordered_json` is deliberately minimal and has no lookup
+The [`ordered_map`](../api/ordered_map/index.md) behind `nlohmann::ordered_json` is deliberately minimal and has no lookup
 index, so every key access is a linear scan and building an object of `n` keys costs O(n²). This is unnoticeable at
 typical object sizes but becomes significant for objects with many thousands of keys; see
-[`ordered_map` complexity](../api/ordered_map.md#complexity). The alternatives above keep a lookup index and do not
+[`ordered_map` complexity](../api/ordered_map/index.md#complexity). The alternatives above keep a lookup index and do not
 have this cost.

 ### Notes on parsing
@@ -79,10 +79,6 @@ follow the usual `std::streambuf` contract, and
 [`JSON_DISABLE_UNLOCKED_FILE_IO`](../../api/macros/json_disable_unlocked_file_io.md) for programs in which another
 thread must use the same `#!cpp FILE` object while it is parsed.

-Where the target has them, strings are scanned with vector instructions: SSE2 on x86-64 (and SSSE3 for UTF-8 text, when
-the CPU has it) and NEON on AArch64. [`JSON_NO_SIMD`](../../api/macros/json_no_simd.md) selects portable code instead,
-again without changing any result.
-
 ## SAX vs. DOM parsing

 The library offers two parsing models:
@@ -20,38 +20,31 @@ below apply on every supported standard. This adapter exposes two optimizations

 - it can reconstruct already-consumed input on demand for error messages, instead of copying every character as it is
  read, and
- the lexer can scan ordinary string characters, numbers, and indentation directly out of the buffer, several bytes at
-  a time, rather than one character (and one function call) at a time.
+- the lexer can scan ordinary string characters directly out of the buffer, several bytes at a time, rather than one
+  character (and one function call) at a time.

-A `#!cpp std::istream` (including `#!cpp std::ifstream`) gets the same bulk scanning: `input_stream_adapter` scans the
-characters its stream buffer already holds (the *get area*) and asks the stream buffer for more only when they are used
-up. Nothing is read ahead, so the stream is left exactly where it would be after reading one character at a time, and
-[`operator>>`](../api/operator_gtgt.md) can still read several values from one stream. A stream buffer without a get
-area is read one character at a time. A `#!cpp FILE*` is still read one character at a time, but `file_input_adapter`
-locks the file once per parse instead of once per character. See
-[input sources and performance](parsing/index.md#input-sources-and-performance) for the full table. According to the
-description of [#5828](https://github.com/nlohmann/json/pull/5828), parsing from a stream is within about 10 to 20 % of
-parsing an equivalent `#!cpp std::string`.
+A `#!cpp std::istream` (including `#!cpp std::ifstream`) or `#!cpp FILE*`, by contrast, is read through
+`input_stream_adapter` or `file_input_adapter`, which read one character (or one block, for binary formats) at a time
+and expose neither optimization -- the lexer falls back to the same byte-at-a-time path it uses for any
+non-contiguous, general-purpose iterator range. An iterator pair over non-contiguous but random-access storage (e.g.
+`#!cpp std::deque<char>::iterator`) gets the first optimization but not the second, since the byte-scanning fast path
+additionally requires contiguous storage.

-Inputs that are still read one character at a time: iterator ranges that are not contiguous (e.g.
-`#!cpp std::list<char>` or `#!cpp std::istreambuf_iterator<char>`), wide strings, and user-defined adapters. An
-iterator pair over non-contiguous but random-access storage (e.g. `#!cpp std::deque<char>::iterator`) gets the first
-optimization but not the second, since the byte-scanning fast path requires contiguous storage.
-
-Practically: a file can be passed directly to `parse`, which also avoids the memory for a copy of the file. Reading it
-into a string first is no longer necessary for speed:
+Practically: if the JSON text is already in memory, or small enough to read into memory, prefer passing a
+`#!cpp std::string`, a `#!cpp std::vector<char>`, or a pointer range to `parse` over a `#!cpp std::istream`. For a
+file, that means reading it into a string first and then parsing the string, rather than passing a
+`#!cpp std::ifstream` directly to `parse` -- the latter never benefits from either optimization:

 ```cpp
-// fast: the stream buffer's get area is scanned in bulk
+// gets the contiguous fast paths
 std::ifstream f("example.json");
-json j = json::parse(f);
-```
+std::string contents((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
+json j = json::parse(contents);

-Two macros switch the stream optimizations off without changing any result:
-[`JSON_DISABLE_STREAM_BULK_SCAN`](../api/macros/json_disable_stream_bulk_scan.md) for stream buffers that do not follow
-the usual `#!cpp std::streambuf` contract, and
-[`JSON_DISABLE_UNLOCKED_FILE_IO`](../api/macros/json_disable_unlocked_file_io.md) for programs in which another thread
-must use the same `#!cpp FILE` object while it is parsed.
+// does not: input_stream_adapter has no fast path
+std::ifstream f2("example.json");
+json j2 = json::parse(f2);
+```

 For contiguous input with many non-ASCII characters, [`JSON_USE_SIMDUTF`](../api/macros/json_use_simdutf.md) can
 additionally speed up UTF-8 validation by using the [simdutf](https://github.com/simdutf/simdutf) library instead of
@@ -101,10 +94,10 @@ whether it is worth the loss of human readability at all -- depends on the actua
 The default [`json`](../api/json.md) type stores object keys in a `#!cpp std::map`, giving logarithmic-time lookup,
 insertion, and erasure, at the cost of sorting keys alphabetically rather than preserving insertion order (see
 [Object Order](object_order.md)). [`ordered_json`](../api/ordered_json.md) uses
-[`nlohmann::ordered_map`](../api/ordered_map.md) instead, a `#!cpp std::vector`-backed container with no lookup index:
+[`nlohmann::ordered_map`](../api/ordered_map/index.md) instead, a `#!cpp std::vector`-backed container with no lookup index:
 every key-based operation is a **linear scan**, so building an object of `n` distinct keys costs **O(n²)** in total --
 this applies equally to inserting keys one by one and to parsing an object, since the parser inserts each key as it is
-read. The [measurements on the `ordered_map` page](../api/ordered_map.md#complexity) show this is
+read. The [measurements on the `ordered_map` page](../api/ordered_map/index.md#complexity) show this is
 negligible at typical object sizes (2000 keys: 0.7 ms for `json` vs. 3.6 ms for `ordered_json`, a 5x factor) but grows
 steeply for large, machine-generated objects (16 000 keys: 3.3 ms vs. 181.6 ms, a 54x factor).

@@ -42,7 +42,7 @@ Requirements are split into two groups:

 | Template parameter                                                | Default                           | Notable substitutes                                                                              |
 |-------------------------------------------------------------------|-----------------------------------|--------------------------------------------------------------------------------------------------|
-| [`ObjectType`](#objecttype)                                       | `std::map`                        | [`nlohmann::ordered_map`](../../api/ordered_map.md), Abseil hash maps                            |
+| [`ObjectType`](#objecttype)                                       | `std::map`                        | [`nlohmann::ordered_map`](../../api/ordered_map/index.md), Abseil hash maps                            |
 | [`ArrayType`](#arraytype)                                         | `std::vector`                     | `#!cpp std::deque`                                                                               |
 | [`StringType`](#stringtype)                                       | `std::string`                     | `std::string`-like types over `char`                                                             |
 | [`BooleanType`](#booleantype)                                     | `bool`                            | none worth using                                                                                 |
@@ -235,7 +235,7 @@ The library does not sort or de-duplicate keys itself; the behavior described in
 | Container                                                                        | Notes                                                                         |
 |----------------------------------------------------------------------------------|-------------------------------------------------------------------------------|
 | `#!cpp std::map` (default)                                                       |                                                                               |
-| [`nlohmann::ordered_map`](../../api/ordered_map.md)                              | used by [`ordered_json`](../../api/ordered_json.md); keeps insertion order    |
+| [`nlohmann::ordered_map`](../../api/ordered_map/index.md)                              | used by [`ordered_json`](../../api/ordered_json.md); keeps insertion order    |
 | [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map)                     | keeps insertion order; adapter puts `fifo_map_compare` in the comparator slot |
 | `boost::container::map`, `boost::container::flat_map`                            | no adapter needed                                                             |
 | `#!cpp std::unordered_map`                                                       | through the adapter above; not with libstdc++ 9, see the note                 |
@@ -50,7 +50,7 @@ The public headers are in [`include/nlohmann`](https://github.com/nlohmann/json/
 - [`adl_serializer.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/adl_serializer.hpp), [`byte_container_with_subtype.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/byte_container_with_subtype.hpp), and [`ordered_map.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/ordered_map.hpp) define
  [`adl_serializer`](../api/adl_serializer/index.md),
  [`byte_container_with_subtype`](../api/byte_container_with_subtype/index.md), and
-  [`ordered_map`](../api/ordered_map.md).
+  [`ordered_map`](../api/ordered_map/index.md).
 - [`json_view.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/json_view.hpp) is a separate,
  optional header that defines [`basic_json_document`](../api/basic_json_document/index.md) and
  [`basic_json_view`](../api/basic_json_view/index.md), a flat-index, read-only, non-owning way to look at a parsed
@@ -64,7 +64,7 @@ below are relative to `include/nlohmann`.
 |-----------|----------|
 | Value type enumeration | [`detail/value_t.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/value_t.hpp) |
 | Input adapters | [`detail/input/input_adapters.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/input_adapters.hpp) |
-| Lexer | [`detail/input/lexer.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/lexer.hpp), [`detail/input/number_parse.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/number_parse.hpp), [`detail/input/string_scan.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/string_scan.hpp), [`detail/input/simd_scan.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/simd_scan.hpp) |
+| Lexer | [`detail/input/lexer.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/lexer.hpp), [`detail/input/number_parse.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/number_parse.hpp), [`detail/input/string_scan.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/string_scan.hpp) |
 | Parser | [`detail/input/parser.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/parser.hpp) |
 | SAX interface and DOM builders | [`detail/input/json_sax.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/json_sax.hpp) |
 | Binary format readers | [`detail/input/binary_reader.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/binary_reader.hpp) |
@@ -104,7 +104,7 @@ from `json_view.hpp` and `detail/view/`.
 The library provides two specializations:

 - [`json`](../api/json.md) uses all default template arguments.
- [`ordered_json`](../api/ordered_json.md) uses [`ordered_map`](../api/ordered_map.md) as `ObjectType` to keep the
+- [`ordered_json`](../api/ordered_json.md) uses [`ordered_map`](../api/ordered_map/index.md) as `ObjectType` to keep the
  insertion order of object keys.

 The requirements on the template arguments are listed in
@@ -10,29 +10,6 @@ at its root, a [Natvis](https://learn.microsoft.com/en-us/visualstudio/debugger/
 file that gives `json`/`ordered_json` values a friendly, key/value debugger view instead of showing raw internal
 fields, when debugging with the MSVC debug engine (`cppvsdbg`) in Visual Studio or VS Code.

-The checked-in visualizers cover namespace variants with zero, one, or two ABI tags. Configurations with three or more
-ABI tags are not covered and may show raw internal fields instead. To generate a Natvis file for such a configuration:
-
-1. Check out the release tag of the library version you use.
-2. List the ABI tags and the macros that enable them:
-
-    ```shell
-    make natvis NATVIS_ARGS="--list-tags"
-    ```
-
-3. Generate a Natvis file with the tags of your configuration, for example for `JSON_DIAGNOSTICS`,
-    `JSON_DIAGNOSTIC_POSITIONS`, and `JSON_VIEW_NO_SIMD`:
-
-    ```shell
-    make natvis NATVIS_ARGS="--abi-tags _diag,_dp,_vns --output my_nlohmann_json.natvis"
-    ```
-
-4. Use the generated file instead of `nlohmann_json.natvis`.
-
-`--abi-tags` can be repeated for several configurations, and `--all` generates every combination (about 60 MB for 12
-ABI tags, doubling with each further tag). See
-[`tools/generate_natvis`](https://github.com/nlohmann/json/tree/develop/tools/generate_natvis) for all options.
-
 Debug engines that wrap LLDB instead of the MSVC debug engine (for example, `codelldb` in VS Code) only have
 partial/experimental Natvis support, and commonly fall back to showing raw internal fields even with the
 `.natvis` file present. Switching to `cppvsdbg` where available, or checking your debug extension's own Natvis
@@ -2,7 +2,8 @@

 This page summarizes the notable changes of every release and links to the relevant documentation.
 The **complete release notes** — including all changes, the download files, and their checksums — are
-published on the [GitHub releases page](https://github.com/nlohmann/json/releases).
+published on the [GitHub releases page](https://github.com/nlohmann/json/releases). For a raw,
+signature-level diff of the public API between releases, see [API Changes](api_changes.md).

 !!! info "Unreleased changes"

@@ -52,6 +52,7 @@ nav:
      - "FAQ": home/faq.md
      - home/exceptions.md
      - home/releases.md
+      - home/api_changes.md
      - home/design_goals.md
      - home/architecture.md
      - home/customers.md
@@ -124,6 +125,7 @@ nav:
          - 'begin': api/basic_json/begin.md
          - 'binary': api/basic_json/binary.md
          - 'binary_t': api/basic_json/binary_t.md
+          - 'bjdata_version_t': api/basic_json/bjdata_version_t.md
          - 'boolean_t': api/basic_json/boolean_t.md
          - 'cbegin': api/basic_json/cbegin.md
          - 'cbor_tag_handler_t': api/basic_json/cbor_tag_handler_t.md
@@ -162,6 +164,7 @@ nav:
          - 'get_to': api/basic_json/get_to.md
          - 'std::formatter&lt;basic_json&gt;': api/basic_json/std_formatter.md
          - 'std::hash&lt;basic_json&gt;': api/basic_json/std_hash.md
+          - 'initializer_list_t': api/basic_json/initializer_list_t.md
          - 'input_format_t': api/basic_json/input_format_t.md
          - 'insert': api/basic_json/insert.md
          - 'invalid_iterator': api/basic_json/invalid_iterator.md
@@ -180,6 +183,7 @@ nav:
          - 'is_structured': api/basic_json/is_structured.md
          - 'items': api/basic_json/items.md
          - 'json_base_class_t': api/basic_json/json_base_class_t.md
+          - 'json_sax_t': api/basic_json/json_sax_t.md
          - 'json_serializer': api/basic_json/json_serializer.md
          - 'max_size': api/basic_json/max_size.md
          - 'meta': api/basic_json/meta.md
@@ -303,11 +307,13 @@ nav:
          - 'Overview': api/byte_container_with_subtype/index.md
          - '(constructor)': api/byte_container_with_subtype/byte_container_with_subtype.md
          - 'clear_subtype': api/byte_container_with_subtype/clear_subtype.md
+          - 'container_type': api/byte_container_with_subtype/container_type.md
          - 'has_subtype': api/byte_container_with_subtype/has_subtype.md
          - 'operator==': api/byte_container_with_subtype/operator_eq.md
          - 'operator!=': api/byte_container_with_subtype/operator_ne.md
          - 'set_subtype': api/byte_container_with_subtype/set_subtype.md
          - 'subtype': api/byte_container_with_subtype/subtype.md
+          - 'subtype_type': api/byte_container_with_subtype/subtype_type.md
      - adl_serializer:
          - 'Overview': api/adl_serializer/index.md
          - 'from_json': api/adl_serializer/from_json.md
@@ -337,19 +343,27 @@ nav:
          - 'to_string': api/json_pointer/to_string.md
      - json_sax:
          - 'Overview': api/json_sax/index.md
+          - '(Constructor)': api/json_sax/json_sax.md
+          - '(Destructor)': api/json_sax/~json_sax.md
+          - 'operator=': api/json_sax/operator=.md
          - 'binary': api/json_sax/binary.md
+          - 'binary_t': api/json_sax/binary_t.md
          - 'boolean': api/json_sax/boolean.md
          - 'end_array': api/json_sax/end_array.md
          - 'end_object': api/json_sax/end_object.md
          - 'key': api/json_sax/key.md
          - 'null': api/json_sax/null.md
          - 'number_float': api/json_sax/number_float.md
+          - 'number_float_t': api/json_sax/number_float_t.md
          - 'number_integer': api/json_sax/number_integer.md
+          - 'number_integer_t': api/json_sax/number_integer_t.md
          - 'number_unsigned': api/json_sax/number_unsigned.md
+          - 'number_unsigned_t': api/json_sax/number_unsigned_t.md
          - 'parse_error': api/json_sax/parse_error.md
          - 'start_array': api/json_sax/start_array.md
          - 'start_object': api/json_sax/start_object.md
          - 'string': api/json_sax/string.md
+          - 'string_t': api/json_sax/string_t.md
      - 'json_view': api/json_view.md
      - 'operator<<(basic_json), operator<<(json_pointer)': api/operator_ltlt.md
      - 'operator>>(basic_json)': api/operator_gtgt.md
@@ -360,7 +374,20 @@ nav:
      - 'ordered_json_editable_document': api/ordered_json_editable_document.md
      - 'ordered_json_editable_view': api/ordered_json_editable_view.md
      - 'ordered_json_view': api/ordered_json_view.md
-      - 'ordered_map': api/ordered_map.md
+      - ordered_map:
+          - 'Overview': api/ordered_map/index.md
+          - '(Constructor)': api/ordered_map/ordered_map.md
+          - '(Destructor)': api/ordered_map/~ordered_map.md
+          - 'operator=': api/ordered_map/operator=.md
+          - 'at': api/ordered_map/at.md
+          - 'Container': api/ordered_map/Container.md
+          - 'count': api/ordered_map/count.md
+          - 'emplace': api/ordered_map/emplace.md
+          - 'erase': api/ordered_map/erase.md
+          - 'find': api/ordered_map/find.md
+          - 'insert': api/ordered_map/insert.md
+          - 'key_compare': api/ordered_map/key_compare.md
+          - 'operator[]': api/ordered_map/operator[].md
      - macros:
          - 'Overview': api/macros/index.md
          - 'JSON_ASSERT': api/macros/json_assert.md
@@ -383,7 +410,6 @@ nav:
          - 'JSON_NO_AUTOMATIC_UDLS': api/macros/json_no_automatic_udls.md
          - 'JSON_NOEXCEPTION': api/macros/json_noexception.md
          - 'JSON_NO_IO': api/macros/json_no_io.md
-          - 'JSON_NO_SIMD': api/macros/json_no_simd.md
          - 'JSON_NO_THREAD_LOCAL': api/macros/json_no_thread_local.md
          - 'JSON_PRECISE_STREAM_POSITION': api/macros/json_precise_stream_position.md
          - 'JSON_SKIP_LIBRARY_VERSION_CHECK': api/macros/json_skip_library_version_check.md
@@ -22,7 +22,9 @@ template<typename BinaryType>
 class byte_container_with_subtype : public BinaryType
 {
  public:
+    /// @sa https://json.nlohmann.me/api/byte_container_with_subtype/container_type/
    using container_type = BinaryType;
+    /// @sa https://json.nlohmann.me/api/byte_container_with_subtype/subtype_type/
    using subtype_type = std::uint64_t;

    /// @sa https://json.nlohmann.me/api/byte_container_with_subtype/byte_container_with_subtype/
@@ -54,12 +56,14 @@ class byte_container_with_subtype : public BinaryType
        , m_has_subtype(true)
    {}

+    /// @sa https://json.nlohmann.me/api/byte_container_with_subtype/operator_eq/
    bool operator==(const byte_container_with_subtype& rhs) const
    {
        return std::tie(static_cast<const BinaryType&>(*this), m_subtype, m_has_subtype) ==
               std::tie(static_cast<const BinaryType&>(rhs), rhs.m_subtype, rhs.m_has_subtype);
    }

+    /// @sa https://json.nlohmann.me/api/byte_container_with_subtype/operator_ne/
    bool operator!=(const byte_container_with_subtype& rhs) const
    {
        return !(rhs == *this);
@@ -122,12 +122,6 @@
    #define NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO
 #endif

-#ifdef JSON_NO_SIMD
-    #define NLOHMANN_JSON_ABI_TAG_NO_SIMD _ns
-#else
-    #define NLOHMANN_JSON_ABI_TAG_NO_SIMD
-#endif
-
 #ifdef JSON_VIEW_NO_SIMD
    #define NLOHMANN_JSON_ABI_TAG_VIEW_NO_SIMD _vns
 #else
@@ -145,9 +139,9 @@
 #endif

 // Construct the namespace ABI tags component
-#define NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l, m) json_abi ## a ## b ## c ## d ## e ## f ## g ## h ## i ## j ## k ## l ## m
-#define NLOHMANN_JSON_ABI_TAGS_CONCAT(a, b, c, d, e, f, g, h, i, j, k, l, m) \
-    NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l, m)
+#define NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l) json_abi ## a ## b ## c ## d ## e ## f ## g ## h ## i ## j ## k ## l
+#define NLOHMANN_JSON_ABI_TAGS_CONCAT(a, b, c, d, e, f, g, h, i, j, k, l) \
+    NLOHMANN_JSON_ABI_TAGS_CONCAT_EX(a, b, c, d, e, f, g, h, i, j, k, l)

 #define NLOHMANN_JSON_ABI_TAGS                                       \
    NLOHMANN_JSON_ABI_TAGS_CONCAT(                                   \
@@ -161,7 +155,6 @@
            NLOHMANN_JSON_ABI_TAG_OBJECTS_FOR_ENUM_KEYED_MAPS,       \
            NLOHMANN_JSON_ABI_TAG_DISABLE_STREAM_BULK_SCAN,          \
            NLOHMANN_JSON_ABI_TAG_DISABLE_UNLOCKED_FILE_IO,          \
-            NLOHMANN_JSON_ABI_TAG_NO_SIMD,                           \
            NLOHMANN_JSON_ABI_TAG_VIEW_NO_SIMD,                      \
            NLOHMANN_JSON_ABI_TAG_VIEW_USE_SSSE3)

@@ -14,24 +14,11 @@
    #include <intrin0.h> // __umulh, _umul128, _BitScanForward64, _BitScanReverse64
 #endif

-#ifdef _MSC_VER
-    #include <cstdlib> // _byteswap_ushort, _byteswap_ulong, _byteswap_uint64
-#endif
-#if defined(_MSC_VER) && !defined(__clang__) && (defined(_M_IX86) || defined(_M_ARM))
-    #include <intrin.h> // _BitScanForward, _BitScanReverse
-#endif
-
 #include <nlohmann/detail/macro_scope.hpp> // JSON_HEDLEY_ALWAYS_INLINE, NLOHMANN_JSON_NAMESPACE_BEGIN

-#if defined(__cpp_lib_bit_cast) || defined(__cpp_lib_bitops) || defined(__cpp_lib_byteswap)
-    #include <bit> // bit_cast, byteswap, countl_zero, countr_zero
-#endif
-
 // Portable bit-level helpers for the number and string scanners. They use
-// compiler builtins or platform-specific intrinsics where available, the
-// C++20 <bit> functions next, and plain C++ otherwise, so they work regardless
-// of byte order. (The builtins and intrinsics come first: MSVC's
-// std::countl_zero checks for LZCNT at run time unless AVX2 is enabled.)
+// compiler builtins or platform-specific intrinsics where available and plain
+// C++ otherwise, so they work regardless of byte order.

 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
@@ -46,16 +33,6 @@ inline int count_leading_zeros(std::uint64_t x) noexcept
    unsigned long index = 0; // NOLINT(runtime/int): the type _BitScan*64 takes
    _BitScanReverse64(&index, x);
    return 63 - static_cast<int>(index);
-#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_ARM))
-    unsigned long index = 0; // NOLINT(runtime/int): the type _BitScan* takes
-    if (_BitScanReverse(&index, static_cast<unsigned long>(x >> 32u))) // NOLINT(runtime/int)
-    {
-        return 31 - static_cast<int>(index);
-    }
-    _BitScanReverse(&index, static_cast<unsigned long>(x)); // NOLINT(runtime/int)
-    return 63 - static_cast<int>(index);
-#elif defined(__cpp_lib_bitops)
-    return std::countl_zero(x);
 #else
    int n = 0;
    for (int shift = 32; shift != 0; shift >>= 1)
@@ -79,16 +56,6 @@ inline int count_trailing_zeros(std::uint64_t x) noexcept
    unsigned long index = 0; // NOLINT(runtime/int): the type _BitScan*64 takes
    _BitScanForward64(&index, x);
    return static_cast<int>(index);
-#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_ARM))
-    unsigned long index = 0; // NOLINT(runtime/int): the type _BitScan* takes
-    if (_BitScanForward(&index, static_cast<unsigned long>(x))) // NOLINT(runtime/int)
-    {
-        return static_cast<int>(index);
-    }
-    _BitScanForward(&index, static_cast<unsigned long>(x >> 32u)); // NOLINT(runtime/int)
-    return 32 + static_cast<int>(index);
-#elif defined(__cpp_lib_bitops)
-    return std::countr_zero(x);
 #else
    int n = 0;
    for (int shift = 32; shift != 0; shift >>= 1)
@@ -103,67 +70,6 @@ inline int count_trailing_zeros(std::uint64_t x) noexcept
 #endif
 }

-/// the object representation of @a from as a @a To (std::bit_cast in C++20)
-template<typename To, typename From>
-JSON_HEDLEY_ALWAYS_INLINE To bit_cast(const From& from) noexcept
-{
-    static_assert(sizeof(To) == sizeof(From), "bit_cast needs types of the same size");
-#if defined(__cpp_lib_bit_cast)
-    return std::bit_cast<To>(from);
-#else
-    To to {};
-    std::memcpy(&to, &from, sizeof(To));
-    return to;
-#endif
-}
-
-/// x with its bytes in reverse order (std::byteswap in C++23); compilers lower
-/// it to a single bswap/rev/movbe
-inline std::uint16_t byteswap(std::uint16_t x) noexcept
-{
-#if defined(__GNUC__) || defined(__clang__)
-    return __builtin_bswap16(x);
-#elif defined(_MSC_VER)
-    return _byteswap_ushort(x);
-#elif defined(__cpp_lib_byteswap)
-    return std::byteswap(x);
-#else
-    return static_cast<std::uint16_t>((x >> 8u) | (x << 8u));
-#endif
-}
-
-/// x with its bytes in reverse order (std::byteswap in C++23)
-inline std::uint32_t byteswap(std::uint32_t x) noexcept
-{
-#if defined(__GNUC__) || defined(__clang__)
-    return __builtin_bswap32(x);
-#elif defined(_MSC_VER)
-    return _byteswap_ulong(x);
-#elif defined(__cpp_lib_byteswap)
-    return std::byteswap(x);
-#else
-    return ((x & 0x000000FFu) << 24u) | ((x & 0x0000FF00u) << 8u)
-           | ((x & 0x00FF0000u) >> 8u) | ((x & 0xFF000000u) >> 24u);
-#endif
-}
-
-/// x with its bytes in reverse order (std::byteswap in C++23)
-inline std::uint64_t byteswap(std::uint64_t x) noexcept
-{
-#if defined(__GNUC__) || defined(__clang__)
-    return __builtin_bswap64(x);
-#elif defined(_MSC_VER)
-    return _byteswap_uint64(x);
-#elif defined(__cpp_lib_byteswap)
-    return std::byteswap(x);
-#else
-    x = ((x & 0x00000000FFFFFFFFull) << 32u) | ((x & 0xFFFFFFFF00000000ull) >> 32u);
-    x = ((x & 0x0000FFFF0000FFFFull) << 16u) | ((x & 0xFFFF0000FFFF0000ull) >> 16u);
-    x = ((x & 0x00FF00FF00FF00FFull) << 8u) | ((x & 0xFF00FF00FF00FF00ull) >> 8u);
-    return x;
-#endif
-}
-
 /// the 128-bit product of two 64-bit numbers
 struct uint128_parts
 {
@@ -201,8 +107,8 @@ inline uint128_parts full_multiplication(std::uint64_t a, std::uint64_t b) noexc
 /// targets; always inlined, as GCC otherwise calls it in the number loops)
 JSON_HEDLEY_ALWAYS_INLINE std::uint64_t read_eight_bytes(const unsigned char* b) noexcept
 {
-#if JSON_LITTLE_ENDIAN_TARGET
-    // the byte order already matches
+#if defined(_MSC_VER) || defined(__x86_64__) || defined(__i386__) || (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+    // the byte order already matches (all MSVC targets are little-endian)
    std::uint64_t result = 0;
    std::memcpy(&result, b, sizeof(result));
    return result;
@@ -18,14 +18,17 @@
 #include <limits> // numeric_limits
 #include <type_traits> // conditional

+#ifdef _MSC_VER
+    #include <cstdlib> // _byteswap_uint64
+#endif

 // SSE2 (every x86-64 CPU) and NEON (every 64-bit Arm CPU) convert the 16
-// digits of a double at once (unless JSON_NO_SIMD selects the portable code)
-#if !defined(JSON_NO_SIMD) && (defined(__x86_64__) || (defined(_M_X64) && !defined(_M_ARM64EC)))
+// digits of a double at once
+#if defined(__x86_64__) || (defined(_M_X64) && !defined(_M_ARM64EC))
    #include <emmintrin.h>
    #define JSON_DTOA_SSE2 1
    #define JSON_DTOA_NEON 0
-#elif !defined(JSON_NO_SIMD) && (defined(__aarch64__) || defined(_M_ARM64)) && !defined(_M_ARM64EC) && !defined(__ARM_BIG_ENDIAN)
+#elif (defined(__aarch64__) || defined(_M_ARM64)) && !defined(_M_ARM64EC) && !defined(__ARM_BIG_ENDIAN)
    #include <arm_neon.h>
    #define JSON_DTOA_SSE2 0
    #define JSON_DTOA_NEON 1
@@ -34,7 +37,6 @@
    #define JSON_DTOA_NEON 0
 #endif

-#include <nlohmann/detail/bit_ops.hpp>
 #include <nlohmann/detail/conversions/zmij.hpp>
 #include <nlohmann/detail/macro_scope.hpp>

@@ -64,6 +66,16 @@ For a detailed description of the algorithm see:
 namespace dtoa_impl
 {

+template<typename Target, typename Source>
+Target reinterpret_bits(const Source source)
+{
+    static_assert(sizeof(Target) == sizeof(Source), "size mismatch");
+
+    Target target;
+    std::memcpy(&target, &source, sizeof(Source));
+    return target;
+}
+
 struct diyfp // f * 2^e
 {
    static constexpr int kPrecision = 64; // = q
@@ -218,7 +230,7 @@ boundaries compute_boundaries(FloatType value)

    using bits_type = typename std::conditional<kPrecision == 24, std::uint32_t, std::uint64_t >::type;

-    const auto bits = static_cast<std::uint64_t>(bit_cast<bits_type>(value));
+    const auto bits = static_cast<std::uint64_t>(reinterpret_bits<bits_type>(value));
    const std::uint64_t E = bits >> (kPrecision - 1);
    const std::uint64_t F = bits & (kHiddenBit - 1);

@@ -1072,10 +1084,13 @@ inline std::uint64_t eight_digit_bytes(std::uint64_t abcdefgh) noexcept
 /// the byte stores once this is inlined)
 inline void store_msb_first(char* p, std::uint64_t v) noexcept
 {
-#if JSON_LITTLE_ENDIAN_TARGET
-    v = byteswap(v);
+#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+    v = __builtin_bswap64(v);
    std::memcpy(p, &v, sizeof(v));
-#elif JSON_BIG_ENDIAN_TARGET
+#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+    std::memcpy(p, &v, sizeof(v));
+#elif defined(_MSC_VER) // (little-endian on all its targets)
+    v = _byteswap_uint64(v);
    std::memcpy(p, &v, sizeof(v));
 #else
    for (unsigned i = 0; i < 8; ++i)
@@ -1447,7 +1462,8 @@ char* write_positive_zmij(char* first, const char* last, FloatType value)
 {
    static_assert(is_binary64<FloatType>::value,
                  "internal error: the conversion of Zmij needs IEEE 754 binary64 numbers");
-    const auto bits = bit_cast<std::uint64_t>(value);
+    std::uint64_t bits = 0;
+    std::memcpy(&bits, &value, sizeof(bits));
    const zmij::shortest_decimal d = zmij::to_shortest(bits);
    if (JSON_HEDLEY_LIKELY(last - first >= 41))
    {
@@ -34,15 +34,21 @@ input.
 template<typename BasicJsonType>
 struct json_sax
 {
+    /// @sa https://json.nlohmann.me/api/json_sax/number_integer_t/
    using number_integer_t = typename BasicJsonType::number_integer_t;
+    /// @sa https://json.nlohmann.me/api/json_sax/number_unsigned_t/
    using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+    /// @sa https://json.nlohmann.me/api/json_sax/number_float_t/
    using number_float_t = typename BasicJsonType::number_float_t;
+    /// @sa https://json.nlohmann.me/api/json_sax/string_t/
    using string_t = typename BasicJsonType::string_t;
+    /// @sa https://json.nlohmann.me/api/json_sax/binary_t/
    using binary_t = typename BasicJsonType::binary_t;

    /*!
    @brief a null value was read
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/null/
    */
    virtual bool null() = 0;

@@ -50,6 +56,7 @@ struct json_sax
    @brief a boolean value was read
    @param[in] val  boolean value
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/boolean/
    */
    virtual bool boolean(bool val) = 0;

@@ -57,6 +64,7 @@ struct json_sax
    @brief an integer number was read
    @param[in] val  integer value
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/number_integer/
    */
    virtual bool number_integer(number_integer_t val) = 0;

@@ -64,6 +72,7 @@ struct json_sax
    @brief an unsigned integer number was read
    @param[in] val  unsigned integer value
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/number_unsigned/
    */
    virtual bool number_unsigned(number_unsigned_t val) = 0;

@@ -72,6 +81,7 @@ struct json_sax
    @param[in] val  floating-point value
    @param[in] s    raw token value
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/number_float/
    */
    virtual bool number_float(number_float_t val, const string_t& s) = 0;

@@ -80,6 +90,7 @@ struct json_sax
    @param[in] val  string value
    @return whether parsing should proceed
    @note It is safe to move the passed string value.
+    @sa https://json.nlohmann.me/api/json_sax/string/
    */
    virtual bool string(string_t& val) = 0;

@@ -88,6 +99,7 @@ struct json_sax
    @param[in] val  binary value
    @return whether parsing should proceed
    @note It is safe to move the passed binary value.
+    @sa https://json.nlohmann.me/api/json_sax/binary/
    */
    virtual bool binary(binary_t& val) = 0;

@@ -96,6 +108,7 @@ struct json_sax
    @param[in] elements  number of object elements or -1 if unknown
    @return whether parsing should proceed
    @note binary formats may report the number of elements
+    @sa https://json.nlohmann.me/api/json_sax/start_object/
    */
    virtual bool start_object(std::size_t elements) = 0;

@@ -104,12 +117,14 @@ struct json_sax
    @param[in] val  object key
    @return whether parsing should proceed
    @note It is safe to move the passed string.
+    @sa https://json.nlohmann.me/api/json_sax/key/
    */
    virtual bool key(string_t& val) = 0;

    /*!
    @brief the end of an object was read
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/end_object/
    */
    virtual bool end_object() = 0;

@@ -118,12 +133,14 @@ struct json_sax
    @param[in] elements  number of array elements or -1 if unknown
    @return whether parsing should proceed
    @note binary formats may report the number of elements
+    @sa https://json.nlohmann.me/api/json_sax/start_array/
    */
    virtual bool start_array(std::size_t elements) = 0;

    /*!
    @brief the end of an array was read
    @return whether parsing should proceed
+    @sa https://json.nlohmann.me/api/json_sax/end_array/
    */
    virtual bool end_array() = 0;

@@ -133,16 +150,23 @@ struct json_sax
    @param[in] last_token  the last read token
    @param[in] ex          an exception object describing the error
    @return whether parsing should proceed (must return false)
+    @sa https://json.nlohmann.me/api/json_sax/parse_error/
    */
    virtual bool parse_error(std::size_t position,
                             const std::string& last_token,
                             const detail::exception& ex) = 0;

+    /// @sa https://json.nlohmann.me/api/json_sax/json_sax/
    json_sax() = default;
+    /// @sa https://json.nlohmann.me/api/json_sax/json_sax/
    json_sax(const json_sax&) = default;
+    /// @sa https://json.nlohmann.me/api/json_sax/json_sax/
    json_sax(json_sax&&) noexcept = default;
+    /// @sa https://json.nlohmann.me/api/json_sax/operator=/
    json_sax& operator=(const json_sax&) = default;
+    /// @sa https://json.nlohmann.me/api/json_sax/operator=/
    json_sax& operator=(json_sax&&) noexcept = default;
+    /// @sa https://json.nlohmann.me/api/json_sax/~json_sax/
    virtual ~json_sax() = default;
 };

@@ -418,9 +442,8 @@ class json_sax_dom_parser
        JSON_ASSERT(!ref_stack.empty());
        JSON_ASSERT(ref_stack.back()->is_object());

-        // add null at the given key and store the reference for later; the
-        // key is moved, as the lexer starts the next token with reset()
-        object_element = &(ref_stack.back()->m_data.m_value.object->operator[](std::move(val)));
+        // add null at the given key and store the reference for later
+        object_element = &(ref_stack.back()->m_data.m_value.object->operator[](val));
        return true;
    }

@@ -12,7 +12,6 @@
 #include <cstddef> // size_t
 #include <cstdint> // uint32_t
 #include <cstdio> // snprintf
-#include <cstring> // memcmp
 #include <initializer_list> // initializer_list
 #include <string> // char_traits, string
 #include <utility> // move
@@ -418,43 +417,30 @@ class lexer : public lexer_base<BasicJsonType>
    }

    /// contiguous input: bulk-append the run of ordinary characters and complete
-    /// well-formed UTF-8 sequences starting at the current read position, then
-    /// read the first byte that needs individual handling (the closing quote, an
-    /// escape, a control character, or an ill-formed UTF-8 byte) like get().
-    /// That byte is taken from the buffer that was just scanned. Through get(),
-    /// Apple Clang merged this read with the other get() calls of the scan
-    /// function, which load the read position again right after it was stored
-    /// (3% of json::accept() on jeopardy.json on Apple M1).
-    char_int_type get_after_string_run(std::true_type /*bulk*/)
+    /// well-formed UTF-8 sequences starting at the current read position, leaving
+    /// the first byte that needs individual handling (the closing quote, an
+    /// escape, a control character, or an ill-formed UTF-8 byte) for get()
+    void scan_string_bulk(std::true_type /*bulk*/)
    {
        // a pending unget must be consumed through the normal path first
        if (next_unget)
        {
-            return get();
+            return;
        }
        const std::size_t remaining = ia.bulk_remaining();
        if (remaining == 0)
        {
-            return get();
+            return;
        }
-        const auto* const raw = ia.bulk_data();
-        const auto* const data = reinterpret_cast<const unsigned char*>(raw);
+        const auto* const data = reinterpret_cast<const unsigned char*>(ia.bulk_data());

-        const std::size_t pos = lexer_string_bulk_run(data, remaining);
-        if (pos != 0)
+        const std::size_t pos = string_bulk_run(data, remaining);
+        if (pos == 0)
        {
-            token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), pos);
-            bulk_consume(reinterpret_cast<const char*>(data), pos);
+            return;
        }
-        if (pos == remaining)
-        {
-            return get(); // end of the contiguous input
-        }
-        // what get() does, with the byte at hand
-        advance_position();
-        ia.bulk_skip(1);
-        current = char_traits<char_type>::to_int_type(raw[pos]);
-        return track_after_read();
+        token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), pos);
+        bulk_consume(reinterpret_cast<const char*>(data), pos);
    }

    /// consume @a n characters at @a data (the adapter's bulk_data()) and do
@@ -487,10 +473,7 @@ class lexer : public lexer_base<BasicJsonType>
    }

    /// streaming input: no bulk fast path
-    char_int_type get_after_string_run(std::false_type /*bulk*/)
-    {
-        return get();
-    }
+    void scan_string_bulk(std::false_type /*bulk*/) const noexcept {}

    /*!
    @brief scan a string literal
@@ -518,8 +501,11 @@ class lexer : public lexer_base<BasicJsonType>
        while (true)
        {
            // bulk-consume ordinary characters from contiguous input, then
-            // get the next character, the one that ends the run
-            switch (get_after_string_run(std::integral_constant<bool, bulk_scan>()))
+            // handle the next special byte through the switch below
+            scan_string_bulk(std::integral_constant<bool, bulk_scan> {});
+
+            // get the next character
+            switch (get())
            {
                // end of file while parsing the string
                case char_traits<char_type>::eof():
@@ -1639,12 +1625,9 @@ scan_number_done:
        const std::size_t avail = rem + 1;

        // validate + classify the number extent (mirrors scan_number()'s grammar)
-        // and accumulate the mantissa digits on the way, so that tokens with up
-        // to 19 digits need no second pass for their value
        std::size_t i = 0;
        std::size_t dot_index = std::string::npos;
        token_type number_type = token_type::value_unsigned;
-        std::uint64_t w = 0;
        if (data[0] == '-')
        {
            number_type = token_type::value_integer;
@@ -1654,21 +1637,22 @@ scan_number_done:
                return token_type::uninitialized;
            }
        }
-        const std::size_t integer_begin = i;
        if (data[i] == '0')
        {
            ++i;
        }
        else if (data[i] >= '1' && data[i] <= '9')
        {
-            i = accumulate_digits(data, i, avail, w);
+            ++i;
+            while (i < avail && data[i] >= '0' && data[i] <= '9')
+            {
+                ++i;
+            }
        }
        else
        {
            return token_type::uninitialized;
        }
-        std::size_t digit_count = i - integer_begin;
-        std::size_t fraction_digits = 0;
        if (i < avail && data[i] == '.')
        {
            number_type = token_type::value_float;
@@ -1678,39 +1662,29 @@ scan_number_done:
            {
                return token_type::uninitialized;
            }
-            const std::size_t fraction_begin = i;
-            i = accumulate_digits(data, i, avail, w);
-            fraction_digits = i - fraction_begin;
-            digit_count += fraction_digits;
+            while (i < avail && data[i] >= '0' && data[i] <= '9')
+            {
+                ++i;
+            }
        }
        // the mantissa ends here, whether or not an exponent part follows
        const std::size_t mantissa_end = i;
-        std::int64_t exponent = 0;
        if (i < avail && (data[i] == 'e' || data[i] == 'E'))
        {
            number_type = token_type::value_float;
            ++i;
-            bool negative_exponent = false;
            if (i < avail && (data[i] == '+' || data[i] == '-'))
            {
-                negative_exponent = data[i] == '-';
                ++i;
            }
            if (i >= avail || !(data[i] >= '0' && data[i] <= '9'))
            {
                return token_type::uninitialized;
            }
-            // saturated far beyond every range, see parse_float_exponent()
-            constexpr std::int64_t saturation = 100000000000000000; // 10^17
            while (i < avail && data[i] >= '0' && data[i] <= '9')
            {
-                if (exponent < saturation)
-                {
-                    exponent = (exponent * 10) + (data[i] - '0');
-                }
                ++i;
            }
-            exponent = negative_exponent ? -exponent : exponent;
        }
        const std::size_t len = i;
        if (number_may_continue(len == avail, std::integral_constant<bool, bulk_window> {}))
@@ -1731,10 +1705,7 @@ scan_number_done:
 #if !JSON_DIAGNOSTIC_POSITIONS
        if (number_type != token_type::value_float)
        {
-            // up to 18 digits always fit into std::uint64_t and std::int64_t
-            const token_type integer_result = (digit_count <= 18)
-                                              ? store_integer(number_type, w)
-                                              : convert_integer(number_type, data, data + len);
+            const token_type integer_result = convert_integer(number_type, data, data + len);
            if (JSON_HEDLEY_LIKELY(integer_result != token_type::uninitialized))
            {
                bulk_consume(data + 1, len - 1);
@@ -1748,42 +1719,15 @@ scan_number_done:
        }
 #endif

+        // materialize the token exactly as scan_number() would. reset() already
+        // cleared token_buffer, so append() fills it (assign() is avoided
+        // because custom string_t types need not provide it)
+        token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), len);
        decimal_point_position = dot_index;

        bulk_consume(data + 1, len - 1);
        read_number_terminator(std::integral_constant<bool, bulk_window> {});

-        // a float whose digits all fit into w converts from the accumulated
-        // value; longer ones (and other float formats) take the general path
-        if (number_type == token_type::value_float && digit_count <= 19)
-        {
-            float_significand s;
-            s.w = w;
-            s.exponent = exponent - static_cast<std::int64_t>(fraction_digits);
-            s.negative = data[0] == '-';
-            if (convert_accumulated_float(s, std::integral_constant<bool, has_native_float_format<number_float_t>::value> {}))
-            {
-                // the token text is only copied into token_buffer when
-                // get_string() asks for it; the library's own SAX handlers
-                // ignore it. A window into a stream may be refilled by the
-                // next read, so there the text is copied right away.
-                if (bulk_window)
-                {
-                    token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), len);
-                }
-                else
-                {
-                    pending_number_text = data;
-                    pending_number_length = len;
-                }
-                return token_type::value_float;
-            }
-        }
-
-        // materialize the token exactly as scan_number() would. reset() already
-        // cleared token_buffer, so append() fills it (assign() is avoided
-        // because custom string_t types need not provide it)
-        token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(data), len);
        return convert_number(number_type, mantissa_end);
    }

@@ -1812,35 +1756,6 @@ scan_number_done:
    /// the input is not handed back, so the terminator can stay unread
    void read_number_terminator(std::false_type /*window*/) const noexcept {}

-    /// binary32/binary64: the value of a float token from its accumulated
-    /// significand (see scan_number_bulk_contiguous())
-    bool convert_accumulated_float(const float_significand& s, std::true_type /*native*/) noexcept
-    {
-        value_float = decimal_to_float<number_float_t>(s);
-        return true;
-    }
-
-    /// other formats (e.g. x87 long double): not instantiated for them, as
-    /// decimal_to_float() only supports binary32/binary64
-    static bool convert_accumulated_float(const float_significand& /*s*/, std::false_type /*native*/) noexcept
-    {
-        return false;
-    }
-
-    /// the value of an integer token with at most 18 digits, accumulated in @a w
-    token_type store_integer(token_type number_type, std::uint64_t w) noexcept
-    {
-        if (number_type == token_type::value_unsigned)
-        {
-            value_unsigned = static_cast<number_unsigned_t>(w);
-            // reject values that do not round-trip into a narrower type
-            return (static_cast<std::uint64_t>(value_unsigned) == w) ? token_type::value_unsigned : token_type::uninitialized;
-        }
-        const std::int64_t x = -static_cast<std::int64_t>(w);
-        value_integer = static_cast<number_integer_t>(x);
-        return (static_cast<std::int64_t>(value_integer) == x) ? token_type::value_integer : token_type::uninitialized;
-    }
-
    /// contiguous input: try the number fast path, else the byte-path scanner
    token_type scan_number_dispatch(std::true_type /*bulk*/)
    {
@@ -1855,23 +1770,18 @@ scan_number_done:
    }

    /*!
-    @param[in] rest         the literal text after its first character, which
-                            is current (its length is a template parameter, so
-                            that the comparison of the contiguous fast path is
-                            a fixed-size load, not a call of memcmp)
-    @param[in] return_type  the token type to return on success
+    @param[in] literal_text  the literal text to expect
+    @param[in] length        the length of the passed literal text
+    @param[in] return_type   the token type to return on success
    */
-    template<std::size_t N>
-    JSON_HEDLEY_NEVER_INLINE token_type scan_literal(const char (&rest)[N], token_type return_type) // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+    JSON_HEDLEY_NON_NULL(2)
+    token_type scan_literal(const char_type* literal_text, const std::size_t length,
+                            token_type return_type)
    {
-        constexpr std::size_t length = N - 1;
-        if (scan_literal_bulk(rest, length, std::integral_constant<bool, bulk_scan> {}))
+        JSON_ASSERT(char_traits<char_type>::to_char_type(current) == literal_text[0]);
+        for (std::size_t i = 1; i < length; ++i)
        {
-            return return_type;
-        }
-        for (std::size_t i = 0; i < length; ++i)
-        {
-            if (JSON_HEDLEY_UNLIKELY(char_traits<char_type>::to_char_type(get()) != static_cast<char_type>(rest[i])))
+            if (JSON_HEDLEY_UNLIKELY(char_traits<char_type>::to_char_type(get()) != literal_text[i]))
            {
                error_message = "invalid literal";
                return token_type::parse_error;
@@ -1880,27 +1790,6 @@ scan_number_done:
        return return_type;
    }

-    /// contiguous input: compare the rest of a literal at once; false (and
-    /// nothing consumed) if it does not match, so that the byte path reports
-    /// the error at the right character
-    JSON_HEDLEY_ALWAYS_INLINE bool scan_literal_bulk(const char* rest, const std::size_t length, std::true_type /*bulk*/)
-    {
-        if (next_unget || ia.bulk_remaining() < length
-                || std::memcmp(ia.bulk_data(), rest, length) != 0)
-        {
-            return false;
-        }
-        bulk_consume(reinterpret_cast<const char*>(ia.bulk_data()), length);
-        current = static_cast<char_int_type>(static_cast<unsigned char>(rest[length - 1]));
-        return true;
-    }
-
-    /// streaming input: no bulk fast path
-    bool scan_literal_bulk(const char* /*rest*/, const std::size_t /*length*/, std::false_type /*bulk*/) const noexcept
-    {
-        return false;
-    }
-
    /////////////////////
    // input management
    /////////////////////
@@ -1909,7 +1798,6 @@ scan_number_done:
    void reset() noexcept
    {
        token_buffer.clear();
-        pending_number_text = nullptr;
        decimal_point_position = std::string::npos;

 #if JSON_DIAGNOSTIC_POSITIONS
@@ -2169,30 +2057,10 @@ scan_number_done:
    /// return current string value
    string_t& get_string()
    {
-        if (pending_number_text != nullptr)
-        {
-            token_buffer.append(reinterpret_cast<const typename string_t::value_type*>(pending_number_text), pending_number_length);
-            pending_number_text = nullptr;
-        }
        // a number token holds '.' regardless of the locale (#4084)
        return token_buffer;
    }

-    /// the value of a string token (key or string), which never has pending
-    /// number text, so get_string()'s check is not needed
-    string_t& get_string_token() noexcept
-    {
-        JSON_ASSERT(pending_number_text == nullptr);
-        return token_buffer;
-    }
-
-    /// the text of a float token for a SAX handler that ignores it (the
-    /// library's own handlers): empty, without copying the token
-    const string_t& get_ignored_number_text() const noexcept
-    {
-        return token_buffer;
-    }
-
    /////////////////////
    // diagnostics
    /////////////////////
@@ -2526,14 +2394,21 @@ scan_number_done:
                return token_type::value_separator;

            // literals
-            // (the text after the first character; no local arrays, which
-            // would give this function a stack canary on every token)
            case 't':
-                return scan_literal("rue", token_type::literal_true);
+            {
+                std::array<char_type, 4> true_literal = {{static_cast<char_type>('t'), static_cast<char_type>('r'), static_cast<char_type>('u'), static_cast<char_type>('e')}};
+                return scan_literal(true_literal.data(), true_literal.size(), token_type::literal_true);
+            }
            case 'f':
-                return scan_literal("alse", token_type::literal_false);
+            {
+                std::array<char_type, 5> false_literal = {{static_cast<char_type>('f'), static_cast<char_type>('a'), static_cast<char_type>('l'), static_cast<char_type>('s'), static_cast<char_type>('e')}};
+                return scan_literal(false_literal.data(), false_literal.size(), token_type::literal_false);
+            }
            case 'n':
-                return scan_literal("ull", token_type::literal_null);
+            {
+                std::array<char_type, 4> null_literal = {{static_cast<char_type>('n'), static_cast<char_type>('u'), static_cast<char_type>('l'), static_cast<char_type>('l')}};
+                return scan_literal(null_literal.data(), null_literal.size(), token_type::literal_null);
+            }

            // string
            case '\"':
@@ -2581,11 +2456,6 @@ scan_number_done:
    /// whether the next get() call should just return current
    bool next_unget = false;

-    /// the text of the current float token in the input, not yet copied into
-    /// token_buffer (see get_string()), or nullptr
-    const char* pending_number_text = nullptr;
-    std::size_t pending_number_length = 0;
-
    /// the start position of the current token
    position_t position {};
Author	SHA1	Message	Date
Niels Lohmann	9222763ab9	Merge branch 'develop' into claude/todo-191-plan-508110 Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-21 10:51:41 +02:00
Niels Lohmann	d13c9e7212	Fix links to moved API pages in the API changes page mkdocs --strict rejects links to pages that only exist as redirects. Also link operator<< to operator_ltlt.md and operator>> to operator_gtgt.md instead of the other way round. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-10 07:42:37 +02:00
Niels Lohmann	522e7465b0	Merge branch 'develop' into claude/todo-191-plan-508110 Regenerate tools/api_checker/api_surface.json with the CI libclang (18.1.1 on Linux) and point the new ordered_map links in features/performance.md to api/ordered_map/index.md. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-10 04:01:42 +02:00
Niels Lohmann	fe4e78e867	Merge branch 'develop' into claude/todo-191-plan-508110 - ordered_map.hpp: develop's refactored members, with this branch's @sa links on every public member - byte_container_with_subtype operator==/!= and ordered_map docs: develop's reviewed text (#5638); drop the now unreferenced examples - basic_json.md: keep both version-history additions - add the docset entries that develop's style check now requires for the 25 API pages this branch adds - regenerate tools/api_checker/api_surface.json for develop's API Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-10-04 17:35:55 +02:00
Niels Lohmann	9196e92520	Merge branch 'develop' into claude/todo-191-plan-508110 Conflicts: none textual. Follow-up fixes for develop's changes: - docs/mkdocs/docs/api/ordered_map/index.md: develop's new paragraph (#5609) was written for api/ordered_map.md; fixed its relative ordered_json.md link for the page's new location, plus two pre-existing links from an earlier merge (ordered_json.md, features/object_order.md) - tools/api_checker/api_surface.json: regenerated with libclang 18.1.1 on Linux (swap() noexcept now includes json_base_class_t; new integral-key contains/count/find/value overloads) Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-30 20:36:12 +02:00
Niels Lohmann	7d22d865dd	Merge branch 'develop' into claude/todo-191-plan-508110 Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-28 22:22:46 +02:00
Niels Lohmann	4c73319d3b	Use one-line module docstrings in the API checker scripts Codacy runs two docstring checkers with opposite rules for module docstrings: with the summary on the first line it reported D213, with the summary on the second line it reports D212. A one-line docstring satisfies both. Keep the summary as the docstring and move the details into a comment below it; nothing reads the module docstrings. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-28 18:42:34 +02:00
Niels Lohmann	da5097abcd	Restore the CI spelling of json_pointer's operator string_t in the API surface The develop merge regenerated api_surface.json on macOS, whose libclang spells the name of the deprecated conversion operator as "operator nlohmann::json_pointer::string_t_helper<...>::type". CI's pinned libclang 18.1.1 on Linux spells it "operator typename string_t_helper<...>::type", so check_api_docs reported the file as out of date. This restores CI's spelling, which is byte-identical to the file CI regenerated. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-27 21:37:14 +02:00
Niels Lohmann	2319f6e6f9	Address Codacy findings in the API checker scripts Put multi-line docstring summaries on their own line, as a single sentence followed by a blank line (pydocstyle D205, D209, D213, D415). Annotate the subprocess import and calls with nosec: they only run fixed argument lists, never through a shell (Bandit B404, B603, B607). Do the same for the three broad except clauses in extract_api.py, which deliberately fall through to the next libclang candidate or skip an unresolvable alias (Bandit B110, B112). Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-27 18:09:03 +02:00
Niels Lohmann	9a0d1c0c47	Merge branch 'develop' into claude/todo-191-plan-508110 Resolve the conflict in docs/mkdocs/docs/home/architecture.md by taking develop's rewritten page and pointing its ordered_map links at the moved api/ordered_map/index.md. Also update the ordered_map.md links develop added in ordered_json.md, object_order.md, and template_parameters.md. Regenerate api_surface.json for the new BON8 functions and the changed comparison operator. Restrict the documented_non_public leak check to @sa URLs into json.nlohmann.me: develop now uses @sa to link GitHub issues from private members such as copy_structured, which is not a documentation leak. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-27 18:07:00 +02:00
Niels Lohmann	1bbb5d400a	Regenerate api_surface.json after merging develop develop added JSON_HEDLEY_WARN_UNUSED_RESULT to a number of basic_json members (#5520) and reworked operator<<'s output adapter, so the committed API surface no longer matched what extract_api.py produces and the "Check for uncommitted API surface changes" step failed. This is the patch the workflow itself uploads for that purpose; the changes are limited to recorded signatures plus the way libclang spells json_pointer's conversion operator. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-09-15 10:06:55 +02:00
Niels Lohmann	08d18d5a82	Merge remote-tracking branch 'origin/develop' into HEAD	2026-09-14 21:26:29 +02:00
Niels LohmannandClaude Sonnet 5	a27065bd12	Regenerate api_surface.json after merging develop develop gained iterator+sentinel support for accept()/parse()/sax_parse()/ from_cbor()/from_msgpack()/from_ubjson()/from_bjdata()/from_bson() (#5205) since this branch was created, which check_api_docs.yml's drift check caught immediately: GitHub's pull_request trigger checks out the PR-vs-base merge commit, not the PR branch in isolation, so CI was comparing the committed api_surface.json (generated before that upstream change existed) against a fresh extraction of a json.hpp that already had it. This superseded an earlier, incorrect diagnosis of the same symptom (a JSON_HAS_RANGES cross-environment pin) -- that fix remains in place since it's still a real, independent determinism improvement for three other JSON_HAS_RANGES-gated locations in type_traits.hpp, but it wasn't the actual cause of this particular mismatch: these new overloads turned out to be unconditional (SFINAE-gated via can_compare_ne, not preprocessor-gated), so no environment-detection difference was involved here at all. Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-11 23:45:46 +02:00
Niels Lohmann	3940f4b730	Merge remote-tracking branch 'origin/develop' into claude/todo-191-plan-508110	2026-07-11 23:43:30 +02:00
Niels LohmannandClaude Sonnet 5	0663907b68	Fix cross-environment API-surface drift and lint findings from CI extract_api.py's own extraction wasn't deterministic across machines, which CI's drift check caught immediately: JSON_HAS_RANGES auto-detects via the standard library's __cpp_lib_ranges feature-test macro, which isn't reliably gated to C++20 mode by every stdlib -- undefined under -std=c++17 with macOS's libc++, but defined under the identical flag with the Ubuntu stdlib CI uses, so parse()/accept()/from_*() extracted different signatures purely depending on which machine ran the extraction. Pinned to -DJSON_HAS_RANGES=0: the deterministic and safe choice, since pinning to 1 was tried first and found to fail to parse on a stdlib without full <ranges> support even when the macro claims otherwise. Also found and fixed a second, independent source of the same class of drift: get_identity_name() used cursor.spelling verbatim for CONVERSION_FUNCTION cursors, which libclang renders as its own internally-canonicalized form of the return type rather than what's literally written. Confirmed for json_pointer::operator string_t() spelling differently on two machines pinned to the identical libclang==18.1.1 wheel, with the JSON_HAS_RANGES fix above ruled out as the cause. Now derived from the cursor's own raw source text instead, immune to libclang's dependent-type resolution differences and incidentally more readable than the libclang-internal forms it replaces. Bumped SURFACE_FORMAT_VERSION to 3 and regenerated all 27 history snapshots and the committed api_surface.json; both fixes are documented in tools/api_checker/history/README.md's format-history log. Also fixes diff_api.py's format_version guard, which only compared the two loaded surfaces against each other and never against SURFACE_FORMAT_VERSION (what this build actually understands) -- two surfaces on the same, newer-than-expected format_version would have silently passed the guard. Remaining fixes are the concretely actionable findings from Codacy's review of the new tools/api_checker/ files: unused imports/variables, a stray f-string with no placeholders. Left the docstring-formatting nitpicks (pydocstyle D2xx/D4xx) and generic subprocess-usage notices alone -- the former has no established convention elsewhere in this codebase's Python tooling to conform to, and the latter are inherent to a dev tool that shells out to git/clang with developer-controlled arguments, not user input. Signed-off-by: Niels Lohmann <mail@nlohmann.me> Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-11 18:59:19 +02:00
Niels LohmannandClaude Sonnet 5	f23b3c63a2	Add AST-based public API checker and fix documentation gaps it found (#3691 ) Adds tools/api_checker/: extract_api.py derives the public API surface directly from the libclang AST (independent of documentation status), check_docs.py flags public entries missing @sa links (and @sa on non-public ones), diff_api.py does an overload-aware breaking/feature diff between two refs, check_macros.py cross- checks documented macros against #define sites, and snapshot_release.py backfills immutable per-release surface snapshots into tools/api_checker/history/ (v3.1.0 through v3.12.0) so diff_api.py can compare releases without live extraction. POLICY.md documents what counts as public API and what stability is guaranteed. Running this tooling against the current tree found and fixed a real documentation backlog: ~25 new API doc pages (ordered_map's methods, json_sax's ctor/dtor/ operator=, byte_container_with_subtype's comparison operators, several orphaned type aliases), each with a compiled and output-verified example, plus missing @sa comments and stale/incorrect Version History entries on several existing pages (found by diffing consecutive release pairs and checking whether the resulting change was actually reflected in the target page's history section). Also adds docs/home/api_changes.md, a per-release, per-function reference of public API changes (v3.1.0 through v3.12.0) generated from the history/ snapshots, complementing (not replacing) the existing release notes. Along the way, found and fixed several extractor bugs by testing against real release tags rather than trusting the algorithm in isolation -- most notably an identity-key scheme based on libclang's USR that encoded the enclosing class template's own arity, and a since-renamed ABI inline-namespace pattern (json_v3_11_0 vs. today's json_abi_v3_11_2) that neither of two earlier regex attempts stripped correctly. Both are documented in extract_api.py's docstrings and tools/api_checker/history/README.md so the failure mode doesn't recur silently. .github/workflows/check_api_docs.yml runs extract_api.py + check_docs.py in CI, advisory-only for now (documented backlog may not be at zero for entities this PR didn't touch), plus a blocking drift check on the committed tools/api_checker/api_surface.json. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-11 18:59:00 +02:00
				`@@ -0,0 +1 @@`
				`Container is std::vector<std::pair<const Key, T>>: true`