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 This superseded an earlier, incorrect diagnosis of the same symptom (a JSON_HAS_RANGES cross-environment pin) -- that fix remains in place since it's still a real, independent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>
Merge remote-tracking branch 'origin/develop' into claude/todo-191-plan-508110
2026-08-13 04:33:18 +00:00 · 2026-07-11 23:45:46 +02:00 · 2026-07-11 23:43:30 +02:00 · 2026-07-11 18:59:19 +02:00 · 2026-07-11 18:59:00 +02:00
192 changed files with 72670 additions and 2186 deletions
@@ -15,14 +15,6 @@ guidance.
 For vulnerabilities in third-party dependencies or modules, please report them directly to the respective maintainers.
 ## Unofficial packages
 This project does not publish an official npm package. The npm package
 [`nlohmann-json`](https://www.npmjs.com/package/nlohmann-json) (or similarly named packages) is not maintained or
 endorsed by this project. See the
 [package managers documentation](https://json.nlohmann.me/integration/package_managers/#npm) for supported
 integration options.
 ## Additional Resources
 - Explore security-related topics and contribute to tools and projects through
@@ -11,7 +11,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
@@ -34,19 +34,19 @@ jobs:
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      - name: Checkout pull request
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          path: main
          ref: ${{ github.event.pull_request.head.sha }}
          persist-credentials: false
      - name: Checkout tools
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          path: tools
          ref: develop
@@ -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
@@ -9,7 +9,7 @@ jobs:
    runs-on: ubuntu-22.04
    steps:
    - name: Harden Runner
-      uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+      uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
      with:
        egress-policy: audit
@@ -27,25 +27,25 @@ jobs:
    steps:
    - name: Harden Runner
-      uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+      uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
      with:
        egress-policy: audit
    - name: Checkout repository
-      uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
      with:
        persist-credentials: false
    # Initializes the CodeQL tools for scanning.
    - name: Initialize CodeQL
-      uses: github/codeql-action/init@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+      uses: github/codeql-action/init@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
      with:
        languages: c-cpp
    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
    # If this step fails, then you should remove it and run the build manually (see below)
    - name: Autobuild
-      uses: github/codeql-action/autobuild@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+      uses: github/codeql-action/autobuild@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+      uses: github/codeql-action/analyze@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
@@ -19,7 +19,7 @@ jobs:
      pull-requests: write
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
@@ -17,12 +17,12 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      - name: 'Checkout Repository'
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: 'Dependency Review'
@@ -27,12 +27,12 @@ jobs:
      security-events: write
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
@@ -43,6 +43,6 @@ jobs:
          output: 'flawfinder_results.sarif'
      - name: Upload analysis results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
        with:
          sarif_file: ${{github.workspace}}/flawfinder_results.sarif
@@ -17,7 +17,7 @@ jobs:
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
@@ -26,7 +26,7 @@ jobs:
      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Run CMake
@@ -45,7 +45,7 @@ jobs:
      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Run CMake
@@ -62,7 +62,7 @@ jobs:
        standard: [11, 14, 17, 20, 23, 26]
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Run CMake
@@ -27,11 +27,11 @@ jobs:
    runs-on: ubuntu-22.04
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
      - name: Install virtual environment
        run: make install_venv -C docs/mkdocs
@@ -36,17 +36,17 @@ jobs:
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      - name: "Checkout code"
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: "Run analysis"
-        uses: ossf/scorecard-action@2d1146689b8cda280b9bc96326124645441f03bc # v2.4.4
+        uses: ossf/scorecard-action@4eaacf0543bb3f2c246792bd56e8cdeffafb205a # v2.4.3
        with:
          results_file: results.sarif
          results_format: sarif
@@ -76,6 +76,6 @@ jobs:
      # Upload the results to GitHub's code scanning dashboard.
      - name: "Upload to code-scanning"
-        uses: github/codeql-action/upload-sarif@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
        with:
          sarif_file: results.sarif
@@ -32,12 +32,12 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      # Checkout project source
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
@@ -61,7 +61,7 @@ jobs:
      # Upload SARIF file generated in previous step
      - name: Upload SARIF file
-        uses: github/codeql-action/upload-sarif@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
        with:
          sarif_file: semgrep.sarif
        if: always()
@@ -16,11 +16,11 @@ jobs:
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
-      - uses: actions/stale@4391f3da665fdf50b6810c1a66712fb9ba21aa93 # v11.0.0
+      - uses: actions/stale@eb5cf3af3ac0a1aa4c9c45633dd1ae542a27a899 # v10.3.0
        with:
          stale-issue-label: 'state: stale'
          stale-pr-label: 'state: stale'
@@ -21,11 +21,11 @@ jobs:
    runs-on: ubuntu-latest
    container: gcc:latest
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -35,7 +35,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
@@ -43,11 +43,11 @@ jobs:
        run: |
          wget -q -O - "https://github.com/facebook/infer/releases/download/v1.3.0/infer-linux-x86_64-v1.3.0.tar.xz" | sudo tar -C /opt -xJ
          sudo ln -s /opt/infer-linux-x86_64-v1.3.0/bin/infer /usr/local/bin/infer
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -60,17 +60,17 @@ jobs:
        target: [ci_test_amalgamation, ci_test_single_header, ci_cppcheck, ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_reuse_compliance, ci_test_valgrind]
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      - name: Install Valgrind
        run: sudo apt-get update ; sudo apt-get install -y valgrind
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -85,11 +85,11 @@ jobs:
    steps:
      - name: Install git, clang-tools, iwyu (ci_single_binaries), and unzip
        run: apt-get update ; apt-get install -y git clang-tools iwyu unzip
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -104,11 +104,11 @@ jobs:
    steps:
      - name: Install build-essential
        run: apt-get update ; apt-get install -y build-essential unzip wget git libssl-dev
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -118,11 +118,11 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Install dependencies and de_DE locale
@@ -142,7 +142,7 @@ jobs:
          name: code-coverage-report
          path: ${{ github.workspace }}/build/html
      - name: Publish report to Coveralls
-        uses: coverallsapp/github-action@8d6379e14d29928660c4ba802d8e85393440b329 # v2.3.8
+        uses: coverallsapp/github-action@5cbfd81b66ca5d10c19b062c04de0199c215fb6e # v2.3.7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          path-to-lcov: ${{ github.workspace }}/build/json.info.filtered.noexcept
@@ -163,15 +163,7 @@ jobs:
          export DEBIAN_FRONTEND=noninteractive
          apt-get update
          apt-get install -y --no-install-recommends software-properties-common ca-certificates gnupg make git
-          # add-apt-repository resolves the PPA through the Launchpad API,
+          add-apt-repository -y ppa:ubuntu-toolchain-r/test
          # which intermittently times out or fails the team lookup (the plain
          # "deb ..." sources below never hit Launchpad and never flake).
          # Retry with backoff so a transient Launchpad blip does not fail CI.
          for attempt in 1 2 3 4 5; do
            add-apt-repository -y ppa:ubuntu-toolchain-r/test && break
            echo "::warning::add-apt-repository ppa:ubuntu-toolchain-r/test failed (attempt ${attempt}/5); retrying"
            sleep $((attempt * 10))
          done
          apt-add-repository -y "deb http://archive.ubuntu.com/ubuntu/ bionic main"
          apt-add-repository -y "deb http://archive.ubuntu.com/ubuntu/ bionic universe"
          apt-add-repository -y "deb http://archive.ubuntu.com/ubuntu/ xenial main"
@@ -180,11 +172,11 @@ jobs:
          apt-add-repository -y "deb http://archive.ubuntu.com/ubuntu/ xenial-updates universe"
          apt-get update
          apt-get install -y --no-install-recommends g++-${{ matrix.compiler }}
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: CXX=g++-${{ matrix.compiler }} cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -198,11 +190,11 @@ jobs:
        compiler: ['7', '8', '9', '10', '11', '12', '13', '14', '15', 'latest']
    container: gcc:${{ matrix.compiler }}
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -212,14 +204,14 @@ jobs:
    runs-on: ubuntu-latest
    strategy:
      matrix:
-        compiler: ['3.4', '3.5', '3.6', '3.7', '3.8', '3.9', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15-bullseye', '16', '17', '18', '19', '20', '21', '22', 'latest']
+        compiler: ['3.4', '3.5', '3.6', '3.7', '3.8', '3.9', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15-bullseye', '16', '17', '18', '19', '20', 'latest']
    container: silkeh/clang:${{ matrix.compiler }}
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Set env FORCE_STDCPPFS_FLAG for clang 7 / 8 / 9 / 10
        run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
        if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
@@ -235,11 +227,11 @@ jobs:
      matrix:
        standard: [11, 14, 17, 20, 23, 26]
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -255,11 +247,11 @@ jobs:
    steps:
      - name: Install git and unzip
        run: apt-get update ; apt-get install -y git unzip
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build with libc++
@@ -282,11 +274,11 @@ jobs:
        cuda: ['11.8.0', '12.1.1', '12.6.3']
    container: nvidia/cuda:${{ matrix.cuda }}-devel-ubuntu22.04
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -299,14 +291,14 @@ jobs:
    runs-on: ubuntu-latest
    container: ${{ matrix.container }}
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      # The module test uses `import std;`, which needs CMake's experimental
      # import-std support. Its opt-in token is CMake-version-specific, so pin
      # CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt.
      - name: Get pinned CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
        with:
          cmakeVersion: 4.3.4
      # Clang: the std library module is provided by libc++ (the image's libstdc++
@@ -328,11 +320,11 @@ jobs:
    # Intel's own last officially published image that still includes it.
    container: intel/oneapi-hpckit:2023.2.1-devel-ubuntu22.04
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -345,9 +337,9 @@ jobs:
    runs-on: ubuntu-latest
    container: intel/oneapi-hpckit:latest
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -357,9 +349,9 @@ jobs:
    runs-on: ubuntu-latest
    container: nvcr.io/nvidia/nvhpc:25.5-devel-cuda12.9-ubuntu22.04
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -369,17 +361,17 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
      - name: Install emscripten
        uses: mymindstorm/setup-emsdk@4528d102f7230f0e7b276855c01ea1159be0e984 # v16
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
        run: cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -GNinja
      - name: Build
@@ -392,11 +384,11 @@ jobs:
        target: [ci_test_examples, ci_test_build_documentation]
    steps:
      - name: Harden Runner
-        uses: step-security/harden-runner@b09bb98e06d4d774595224525879c09bc6e98c40 # v2.20.1
+        uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
        with:
          egress-policy: audit
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Run CMake
@@ -24,7 +24,7 @@ jobs:
        architecture: [x64, x86]
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Set up MinGW
@@ -49,7 +49,7 @@ jobs:
    runs-on: windows-2022
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Set extra CXX_FLAGS for latest std_version
@@ -86,9 +86,9 @@ jobs:
    runs-on: windows-2025
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Set extra CXX_FLAGS for latest std_version
        # /wd5285 silences C5285 emitted by the bundled third-party doctest.h, which
        # specializes std::tuple (newly diagnosed by the VS2026 v145 toolset)
@@ -122,7 +122,7 @@ jobs:
    runs-on: windows-11-arm
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
      - name: Run CMake (Release)
        run: cmake -S . -B build -G "Visual Studio 17 2022" -A ARM64 -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
        if: matrix.build_type == 'Release'
@@ -143,7 +143,7 @@ jobs:
        version: [11.0.1, 12.0.1, 13.0.1, 14.0.6, 15.0.7, 16.0.6, 18.1.8, 19.1.7, 20.1.8]
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Install Clang
@@ -153,16 +153,10 @@ jobs:
        with:
          platform: x64
          version: 12.2.0 # https://github.com/egor-tensin/setup-mingw/issues/14
      # CMAKE_CXX_FLAGS_DEBUG is overridden to drop the default -g: linking
      # test-regression2_cpp20 intermittently fails with "relocation truncated
      # to fit: IMAGE_REL_AMD64_SECREL against `.debug_line'" because the
      # MinGW linker cannot relocate the debug sections this test produces.
      # The tests are only built and run here, so the debug info is not used.
      - name: Run CMake
        run: cmake -S . -B build ^
             -DCMAKE_CXX_COMPILER="C:/Program Files/LLVM/bin/clang++.exe" ^
             -DCMAKE_CXX_FLAGS="--target=x86_64-w64-mingw32 -stdlib=libstdc++ -pthread" ^
             -DCMAKE_CXX_FLAGS_DEBUG="-g0" ^
             -DCMAKE_EXE_LINKER_FLAGS="-lwinpthread" ^
             -G"MinGW Makefiles" ^
             -DCMAKE_BUILD_TYPE=Debug ^
@@ -179,7 +173,7 @@ jobs:
        architecture: [Win32, x64]
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Run CMake
@@ -192,14 +186,14 @@ jobs:
  ci_module_cpp20:
    runs-on: windows-2022
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      # The module test uses `import std;`, which needs CMake's experimental
      # import-std support. Its opt-in token is CMake-version-specific, so pin
      # CMake to the version whose token is set in tests/module_cpp20/CMakeLists.txt.
      - name: Get pinned CMake and ninja
-        uses: lukka/get-cmake@4a7d025fc60f00db0c7b44ebf783d19b52444830 # v4.4.1
+        uses: lukka/get-cmake@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
        with:
          cmakeVersion: 4.3.4
      - name: Run CMake (Debug)
@@ -3,6 +3,7 @@
 *.gcno
 *.gcda
 .DS_Store
 __pycache__/
 /.idea
 /cmake-build-*
@@ -43,5 +44,9 @@ 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
@@ -42,7 +42,6 @@
  - [Specializing enum conversion](#specializing-enum-conversion)
  - [Binary formats (BSON, CBOR, MessagePack, UBJSON, and BJData)](#binary-formats-bson-cbor-messagepack-ubjson-and-bjdata)
 - [Customers](#customers)
 - [Ecosystem](#ecosystem)
 - [Supported compilers](#supported-compilers)
 - [Integration](#integration)
  - [CMake](#cmake)
@@ -91,6 +90,7 @@ You can sponsor this library at [GitHub Sponsors](https://github.com/sponsors/nl
 - [Steve Sperandeo](https://github.com/homer6)
 - [Robert Jefe Lindstädt](https://github.com/eljefedelrodeodeljefe)
 - [Steve Wagner](https://github.com/ciroque)
 - [Lion Yang](https://github.com/LionNatsu)
 ### Further support
@@ -106,7 +106,7 @@ 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.
@@ -1187,11 +1187,6 @@ The library is used in multiple projects, applications, operating systems, etc.
 [![logos of customers using the library](docs/mkdocs/docs/images/customers.png)](https://json.nlohmann.me/home/customers/)
 ## Ecosystem
 Beyond projects that use the library, there are third-party projects that build on top of it - schema validators,
 language bindings, format converters, and the like. See the curated [Ecosystem](https://json.nlohmann.me/community/ecosystem/) page.
 ## Supported compilers
 Though it's 2026 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work:
@@ -1807,13 +1802,13 @@ The library itself consists of a single header file licensed under the MIT licen
 - [**amalgamate.py - Amalgamate C source and header files**](https://github.com/edlund/amalgamate) to create a single header file
 - [**American fuzzy lop**](https://lcamtuf.coredump.cx/afl/) for fuzz testing
 - [**AppVeyor**](https://www.appveyor.com) for [continuous integration](https://ci.appveyor.com/project/nlohmann/json) on Windows
- [**Artistic Style**](https://astyle.sourceforge.net) for automatic source code indentation
+- [**Artistic Style**](http://astyle.sourceforge.net) for automatic source code indentation
 - [**Clang**](https://clang.llvm.org) for compilation with code sanitizers
 - [**CMake**](https://cmake.org) for build automation
 - [**Codacy**](https://www.codacy.com) for further [code analysis](https://app.codacy.com/gh/nlohmann/json/dashboard)
 - [**Coveralls**](https://coveralls.io) to measure [code coverage](https://coveralls.io/github/nlohmann/json)
 - [**Coverity Scan**](https://scan.coverity.com) for [static analysis](https://scan.coverity.com/projects/nlohmann-json)
- [**cppcheck**](https://cppcheck.sourceforge.io) for static analysis
+- [**cppcheck**](http://cppcheck.sourceforge.net) for static analysis
 - [**doctest**](https://github.com/onqtam/doctest) for the unit tests
 - [**GitHub Changelog Generator**](https://github.com/skywinder/github-changelog-generator) to generate the [ChangeLog](https://github.com/nlohmann/json/blob/develop/ChangeLog.md)
 - [**Google Benchmark**](https://github.com/google/benchmark) to implement the benchmarks
@@ -1828,15 +1823,6 @@ The library itself consists of a single header file licensed under the MIT licen
 ## Notes
 ### Standards compliance
 The library targets strict conformance with [RFC 8259](https://tools.ietf.org/html/rfc8259.html). Both the original [JSONTestSuite](https://github.com/nst/JSONTestSuite) and its updated revision are exercised in CI; their test data is downloaded from [`nlohmann/json_test_data`](https://github.com/nlohmann/json_test_data) at configure time rather than committed to this repository (see [`tests/src/unit-testsuites.cpp`](https://github.com/nlohmann/json/blob/develop/tests/src/unit-testsuites.cpp)):
 - The updated revision runs all mandatory `y_` (must-accept) and `n_` (must-reject) cases through the strict [`parse()`](https://json.nlohmann.me/api/basic_json/parse/) entry point; the original suite runs its `n_` cases through `parse()` and its `y_` cases through [`operator>>`](https://json.nlohmann.me/api/operator_gtgt/).
 - The `i_` (implementation-defined) cases are, by RFC 8259, free to be accepted *or* rejected, so "passing all `i_` cases" is not a meaningful conformance metric. The library makes deliberate, documented choices there: nesting depth is not artificially limited, a leading UTF-8 byte order mark is silently ignored, [Unicode noncharacters](https://www.unicode.org/faq/private_use.html#nonchar1) are forwarded unchanged, invalid UTF-8 and lone/unpaired UTF-16 surrogates are rejected (stricter than required), and a number that cannot be stored without becoming `NaN`/`INF` raises [`out_of_range.406`](https://json.nlohmann.me/home/exceptions/#jsonexceptionout_of_range406).
 One behavioral nuance is worth calling out, because a superficial test often misreads it as non-compliance: [`parse()`](https://json.nlohmann.me/api/basic_json/parse/) is strict and rejects trailing data after a value, whereas [`operator>>`](https://json.nlohmann.me/api/operator_gtgt/) follows relaxed iostream semantics — it parses a single value and leaves the stream positioned right after it. Feeding "a valid document followed by trailing bytes" through `operator>>` reports success; the same input through `parse()` is rejected. This is a documented two-API design, not a conformance gap. See [**parsing**](https://json.nlohmann.me/features/parsing/) for details.
 ### Character encoding
 The library supports **Unicode input** as follows:
@@ -5,9 +5,6 @@
 # -Wno-extra-semi-stmt            The library uses assert which triggers this warning.
 # -Wno-padded                     We do not care about padding warnings.
 # -Wno-covered-switch-default     All switches list all cases and a default case.
 # -Wno-c2y-extensions             Clang 22.1 diagnoses __COUNTER__ as a C2y extension, also in
 #                                 C++ mode. The library does not use __COUNTER__; the warnings
 #                                 all come from vendored Doctest (SECTION/TEST_CASE macros).
 # -Wno-unsafe-buffer-usage        Pervasive: the library's own low-level numeric/buffer code
 #                                 (to_chars, serializer, lexer, binary reader/writer, input
 #                                 adapters, json_pointer) plus vendored Doctest itself (~208
@@ -23,6 +20,5 @@ set(CLANG_CXXFLAGS
    -Wno-extra-semi-stmt
    -Wno-padded
    -Wno-covered-switch-default
    -Wno-c2y-extensions
    -Wno-unsafe-buffer-usage
 )
@@ -49,7 +49,7 @@ Unlike the [`parse()`](parse.md) function, this function neither throws an excep
 :   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
    - a custom sentinel type for C++20 ranges
-    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
+    - `std::counted_iterator` with a different sentinel type
 ## Parameters
@@ -420,7 +420,9 @@ 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.
+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.
 5. Since version 1.0.0.
 6. Since version 1.0.0.
 7. Since version 1.0.0.
@@ -13,8 +13,9 @@ is compatible with both of the binary data formats that use binary subtyping, (t
 incompatible with each other, and it is up to the user to translate between them). The subtype is added to `BinaryType`
 via the helper type [byte_container_with_subtype](../byte_container_with_subtype/index.md).
-[CBOR's RFC 8949](https://www.rfc-editor.org/rfc/rfc8949.html#section-3.1) describes this type as:
+[CBOR's RFC 7049](https://tools.ietf.org/html/rfc7049) describes this type as:
-> Major type 2: A byte string. The number of bytes in the string is equal to the argument.
+> Major type 2: a byte string. The string's length in bytes is represented following the rules for positive integers
 > (major type 0).
 [MessagePack's documentation on the bin type
 family](https://github.com/msgpack/msgpack/blob/master/spec.md#bin-format-family) describes this type as:
@@ -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.
@@ -43,17 +43,6 @@ Strong guarantee: if an exception is thrown, there are no changes to any JSON va
 Throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if a string stored inside the JSON value
 is not UTF-8 encoded and `error_handler` is set to `strict`
 !!! warning "Serializing untrusted input"
    When serializing values that may contain invalid or untrusted UTF-8 (e.g., bytes taken directly from network
    input), `dump()` throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) in the default
    `strict` mode. To serialize such data without throwing, pass
    [`error_handler_t::replace`](error_handler_t.md) (substitutes U+FFFD) or
    [`error_handler_t::ignore`](error_handler_t.md). Callers that serialize untrusted input on a crash-sensitive path
    should either choose a non-strict error handler or wrap `dump()` in a `#!cpp try`/`#!cpp catch`.
    See the [FAQ](../../home/faq.md#serializing-untrusted-or-invalid-utf-8) for details.
 ## Complexity
 Linear.
@@ -36,10 +36,8 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
-
+    custom sentinel type for C++20 ranges
    - a custom sentinel type for C++20 ranges
    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 ## Parameters
@@ -36,10 +36,8 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
-
+    custom sentinel type for C++20 ranges
    - a custom sentinel type for C++20 ranges
    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 ## Parameters
@@ -39,10 +39,8 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
-
+    custom sentinel type for C++20 ranges
    - a custom sentinel type for C++20 ranges
    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 ## Parameters
@@ -36,10 +36,8 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
-
+    custom sentinel type for C++20 ranges
    - a custom sentinel type for C++20 ranges
    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 ## Parameters
@@ -36,10 +36,8 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
-
+    custom sentinel type for C++20 ranges
    - a custom sentinel type for C++20 ranges
    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 ## Parameters
@@ -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.
@@ -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.
@@ -85,3 +85,8 @@ 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)).
@@ -48,7 +48,7 @@ static basic_json parse(IteratorType first, SentinelType last,
 :   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
    - a custom sentinel type for C++20 ranges
-    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
+    - `std::counted_iterator` with a different sentinel type
 ## Parameters
@@ -29,14 +29,7 @@ Discarding a value (i.e., returning `#!cpp false`) has different effects dependi
 called:
 - Discarded values in structured types are skipped. That is, the parser will behave as if the discarded value was never
-  read. This holds for every value type and for both kinds of parent: a discarded element is removed from the
+  read.
  surrounding array, and a discarded member is removed from the surrounding object together with its key.
 - Arrays and objects can be discarded either at their `parse_event_t::array_start`/`parse_event_t::object_start` event
  or at their `parse_event_t::array_end`/`parse_event_t::object_end` event, and both remove the whole value. Discarding
  it at the start event also means the callback is called neither for the content of the value nor for its matching end
  event.
 - Discarding a `parse_event_t::key` event discards the whole object member. The callback is still called for the
  associated value, but its return value has no further effect.
 - In case a value outside a structured type is skipped, it is replaced with `null`. This case happens if the top-level
  element is skipped.
@@ -56,7 +49,7 @@ called:
 ## Return value
 Whether the JSON value which called the function during parsing should be kept (`#!cpp true`) or not (`#!cpp false`). In
-the latter case, it is skipped completely, or replaced by `null` if it is the top-level value.
+the latter case, it is either skipped completely or replaced by an empty discarded object.
 ## Examples
@@ -75,21 +68,6 @@ the latter case, it is skipped completely, or replaced by `null` if it is the to
    --8<-- "examples/parse__string__parser_callback_t.output"
    ```
 ??? example
    The example below shows where discarded values are removed. The array and the number are discarded in different
    ways, but in each case the parse result contains neither the value nor its key.
    ```cpp
    --8<-- "examples/parser_callback_t.cpp"
    ```
    Output:
    ```json
    --8<-- "examples/parser_callback_t.output"
    ```
 ## See also
 - [parse](parse.md) deserialize from a compatible input
@@ -98,5 +76,3 @@ the latter case, it is skipped completely, or replaced by `null` if it is the to
 ## Version history
 - Added in version 1.0.0.
 - Fixed in version 3.13.0 to also remove discarded values from a parent object; before, discarding an array or a value
  stored under an object key left a discarded member behind, which made the parse result serialize to invalid JSON.
@@ -48,10 +48,7 @@ The SAX event lister must follow the interface of [`json_sax`](../json_sax/index
    with a size of 1, 2, or 4 bytes (interpreted respectively as UTF-8, UTF-16, and UTF-32)
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for overload (2), for instance.
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for overload (2)
    - a custom sentinel type for C++20 ranges
    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 `SAX`
 :   a class fulfilling the SAX event listener interface; see [`json_sax`](../json_sax/index.md)
@@ -40,9 +40,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
  is not an object; example: `"to serialize to BSON, top-level type must be object, but is string"`
 - Throws [`out_of_range.409`](../../home/exceptions.md#jsonexceptionout_of_range409) if a key in the JSON object contains
  a null byte (code point U+0000); example: `"BSON key cannot contain code point U+0000 (at byte 2)"`
 - Throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a document, array,
  string, or binary value exceeds the range of the 32-bit BSON length field; example:
  `"BSON length 2147483661 exceeds maximum of 2147483647"`
 ## Complexity
@@ -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 +1,45 @@
 # <small>nlohmann::byte_container_with_subtype::</small>operator==
 ```cpp
 bool operator==(const byte_container_with_subtype& rhs) const;
 ```
 Compares two `byte_container_with_subtype` values for equality by comparing the underlying binary
 container, the subtype, and whether a subtype is set.
 ## Parameters
 `rhs` (in)
 :   value to compare `*this` against
 ## Return value
 whether `*this` and `rhs` are equal
 ## Exception safety
 No-throw guarantee: this function never throws exceptions.
 ## Complexity
 Linear in the size of the underlying binary container.
 ## Examples
 ??? example
    The example demonstrates comparing `byte_container_with_subtype` values.
    ```cpp
    --8<-- "examples/byte_container_with_subtype__operator_eq.cpp"
    ```
    Output:
    ```
    --8<-- "examples/byte_container_with_subtype__operator_eq.output"
    ```
 ## Version history
 - Since version 3.8.0.
@@ -0,0 +1,45 @@
 # <small>nlohmann::byte_container_with_subtype::</small>operator!=
 ```cpp
 bool operator!=(const byte_container_with_subtype& rhs) const;
 ```
 Compares two `byte_container_with_subtype` values for inequality. Implemented as the negation of
 [`operator==`](operator_eq.md).
 ## Parameters
 `rhs` (in)
 :   value to compare `*this` against
 ## Return value
 whether `*this` and `rhs` are not equal
 ## Exception safety
 No-throw guarantee: this function never throws exceptions.
 ## Complexity
 Linear in the size of the underlying binary container.
 ## Examples
 ??? example
    The example demonstrates comparing `byte_container_with_subtype` values.
    ```cpp
    --8<-- "examples/byte_container_with_subtype__operator_ne.cpp"
    ```
    Output:
    ```
    --8<-- "examples/byte_container_with_subtype__operator_ne.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.
@@ -38,8 +38,7 @@ When the macro is not defined, the library will define it to its default value.
    Diagnostic messages can also be controlled with the CMake option
    [`JSON_Diagnostics`](../../integration/cmake.md#json_diagnostics) (`OFF` by default)
-    which defines `JSON_DIAGNOSTICS` accordingly. Note this only applies when building the
+    which defines `JSON_DIAGNOSTICS` accordingly.
    library from source — see the pre-installed-package caveat on that page.
 ## Examples
@@ -33,44 +33,17 @@ A UTF-8 byte order mark is silently ignored.
 Invalid Unicode escapes and unpaired surrogates in the input are reported as
 [`parse_error.101`](../home/exceptions.md#jsonexceptionparse_error101) with a detailed message.
-`operator>>` parses exactly one JSON value, so it can be called repeatedly to read a sequence of concatenated JSON
+`operator>>` parses exactly one JSON value and leaves the stream positioned right after it, so it can be called
-values from the same stream:
+repeatedly to read a sequence of concatenated JSON values from the same stream:
 ```cpp
 json j1, j2;
-input >> j1;  // parses the first value
+input >> j1;  // parses the first value, stream now positioned right after it
 input >> j2;  // parses the next value
 ```
-!!! warning "A number must be followed by whitespace"
+Note this does **not** work for [JSON Lines](../features/parsing/json_lines.md) (newline-delimited JSON) input --
-
+see that page for why and for the recommended alternative.
    A number is only terminated by the character that follows it. That character is read from the stream to detect the
    end of the number, and it is **not** put back. When a value that is a number is immediately followed by the next
    value, the first character of that next value is lost:
    ```cpp
    std::istringstream input("1true");
    json j1, j2;
    input >> j1;  // j1 == 1
    input >> j2;  // throws parse_error.101: the stream now starts at "rue"
    ```
    Separating the values with whitespace avoids this, because the character that is eaten is then the separator:
    ```cpp
    std::istringstream input("1 true");
    json j1, j2;
    input >> j1;  // j1 == 1
    input >> j2;  // j2 == true
    ```
    Only numbers are affected. Values ending in a self-delimiting character do not read past themselves, so
    `truefalse`, `[1][2]`, `{"a":1}{"b":2}`, and `"a""b"` can be read back to back without a separator.
    This is tracked in [#5340](https://github.com/nlohmann/json/issues/5340).
 Note that reading concatenated values does **not** work for [JSON Lines](../features/parsing/json_lines.md)
 (newline-delimited JSON) input -- see that page for why and for the recommended alternative.
 !!! warning "Deprecation"
@@ -8,17 +8,11 @@ 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
 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.
 ## Examples
 ??? example
@@ -37,7 +31,7 @@ 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
@@ -1,124 +0,0 @@
 # <small>nlohmann::</small>ordered_map
 ```cpp
 template<class Key, class T, class IgnoredLess = std::less<Key>,
         class Allocator = std::allocator<std::pair<const Key, T>>>
 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)
 (`nlohmann::basic_json<ordered_map>`).
 ## Template parameters
 `Key`
 :   key type
 `T`
 :   mapped type
 `IgnoredLess`
 :   comparison function (ignored and only added to ensure compatibility with `#!cpp std::map`)
 `Allocator`
 :   allocator type
 ## Iterator invalidation
 The type uses a `std::vector` to store object elements. Therefore, adding elements can yield a reallocation in which
 case all iterators (including the `end()` iterator) and all references to the elements are invalidated.
 ## 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>`)
 - **iterator**
 - **const_iterator**
 - **size_type**
 - **value_type**
 - **key_compare** - key comparison function
 ```cpp
 std::equal_to<Key>  // until C++14
 std::equal_to<>     // since C++14
 ```
 ## Member functions
 - (constructor)
 - (destructor)
 - **emplace**
 - **operator\[\]**
 - **at**
 - **erase**
 - **count**
 - **find**
 - **insert**
 ## Complexity
 Because the elements are stored in a `std::vector` in insertion order, there is no index to look a key up by. Every
 key-based operation performs a **linear scan** over the stored elements. With `n` denoting the number of elements in the
 container:
 | Operation                              | Complexity     | Note                                                     |
 |----------------------------------------|----------------|----------------------------------------------------------|
 | **emplace**                            | O(n)           | scans for an existing key, then appends (amortized O(1)) |
 | **operator\[\]**                       | O(n)           | delegates to **emplace** (non-const) or **at** (const)   |
 | **at**                                 | O(n)           | throws `#!cpp std::out_of_range` if the key is not found |
 | **find**                               | O(n)           |                                                          |
 | **count**                              | O(n)           | the result is always 0 or 1                              |
 | **erase(key)**                         | O(n)           | scan, then move the remaining elements one position down |
 | **erase(pos)**, **erase(first, last)** | O(n)           | moves all elements after the erased range                |
 | **insert(value)**                      | O(n)           | equivalent to **emplace**                                |
 | **insert(first, last)**                | O((n + m) * m) | for `m` inserted elements                                |
 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
    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
    steeply for machine-generated objects with many thousands of keys. Measured with `-O2 -DNDEBUG` for parsing a flat
    object of `n` keys, relative to `#!cpp nlohmann::json` (which uses `#!cpp std::map`):
    | `n`    | `json` | `ordered_json` | factor |
    |--------|--------|----------------|--------|
    | 2000   | 0.7 ms | 3.6 ms         | 5×     |
    | 4000   | 0.8 ms | 14.0 ms        | 19×    |
    | 8000   | 1.6 ms | 67.8 ms        | 43×    |
    | 16 000 | 3.3 ms | 181.6 ms       | 54×    |
    If key order matters for objects of that size, consider a container with a lookup index, such as
    [`tsl::ordered_map`](https://github.com/Tessil/ordered-map)
    ([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)), as the object type -- see
    [object order](../features/object_order.md).
 ## Examples
 ??? example
    The example shows the different behavior of `std::map` and `nlohmann::ordered_map`.
    ```cpp
    --8<-- "examples/ordered_map.cpp"
    ```
    Output:
    ```json
    --8<-- "examples/ordered_map.output"
    ```
 ## See also
 - [ordered_json](ordered_json.md)
 ## Version history
 - Added in version 3.9.0 to implement [`nlohmann::ordered_json`](ordered_json.md).
 - Added **key_compare** member in version 3.11.0.
@@ -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.
@@ -0,0 +1,83 @@
 # <small>nlohmann::</small>ordered_map
 ```cpp
 template<class Key, class T, class IgnoredLess = std::less<Key>,
         class Allocator = std::allocator<std::pair<const Key, T>>>
 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)
 (`nlohmann::basic_json<ordered_map>`).
 ## Template parameters
 `Key`
 :   key type
 `T`
 :   mapped type
 `IgnoredLess`
 :   comparison function (ignored and only added to ensure compatibility with `#!cpp std::map`)
 `Allocator`
 :   allocator type
 ## Iterator invalidation
 The type uses a `std::vector` to store object elements. Therefore, adding elements can yield a reallocation in which
 case all iterators (including the `end()` iterator) and all references to the elements are invalidated.
 ## Member types
 - **key_type** - key type (`Key`)
 - **mapped_type** - mapped type (`T`)
 - [**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_compare.md) - key comparison function
 ```cpp
 std::equal_to<Key>  // until C++14
 std::equal_to<>     // since C++14
 ```
 ## Member functions
 - [(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)
 ## Examples
 ??? example
    The example shows the different behavior of `std::map` and `nlohmann::ordered_map`.
    ```cpp
    --8<-- "examples/ordered_map.cpp"
    ```
    Output:
    ```json
    --8<-- "examples/ordered_map.output"
    ```
 ## See also
 - [ordered_json](../ordered_json.md)
 ## Version history
 - Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
 - Added **key_compare** member in version 3.11.0.
@@ -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).
@@ -1,40 +0,0 @@
 # Ecosystem
 The projects below build on top of `nlohmann::json` rather than merely using it - schema validators, language
 bindings, format converters, and similar building blocks. The list is not exhaustive, and is curated rather than
 automatically generated. If you maintain or know of a project that belongs here,
 [please let me know](mailto:mail@nlohmann.me).
 For products, applications, and organizations that use the library, see [Customers](../home/customers.md) instead.
 ## Schema validation
 - [**json-schema-validator**](https://github.com/pboettch/json-schema-validator), a JSON Schema (draft 7) validator
  with human-readable error messages
 ## Serialization and reflection
 - [**nlohmann_json_reflect**](https://github.com/1261385937/nlohmann_json_reflect), a reflection extension for
  (de)serializing nested containers-in-structs-in-containers
 ## Encodings
 - [**base-encode-decode**](https://github.com/saxonnicholls/base-encode-decode), a header-only Base64/32/16/8/4/2
  (and DNA/RNA) encoding library, with an adapter that serializes binary data through `nlohmann::json`
 ## Language bindings and interop
 - [**pybind11_json**](https://github.com/pybind/pybind11_json), a bidirectional type caster between
  `nlohmann::json` and Python objects for [pybind11](https://github.com/pybind/pybind11) bindings
 - [**nanobind_json**](https://github.com/ianhbell/nanobind_json), the same idea for
  [nanobind](https://github.com/wjakob/nanobind) bindings
 - [**nlohmann_json_qt**](https://github.com/dpurgin/nlohmann_json_qt), deserialization helpers for Qt types
  (`QString`, `QUrl`, `QDateTime`, `QVector`, ...) from `nlohmann::json`
 - [**vulkan2json**](https://github.com/Fadis/vulkan2json), serialization and deserialization of Vulkan API structs
 ## Format converters
 - [**tojson**](https://github.com/mircodz/tojson), a header-only converter between YAML/XML documents and
  `nlohmann::json`
 - [**json2xml**](https://github.com/testillano/json2xml), a header-only converter from `nlohmann::json` to XML for
  simple configuration documents
@@ -1,6 +1,5 @@
 # Community
 - [Ecosystem](ecosystem.md) - third-party projects built on top of this library
 - [Code of Conduct](code_of_conduct.md) - the rules and norms of this project
 - [Contribution Guidelines](contribution_guidelines.md) - guidelines how to contribute to this project
 - [Governance](governance.md) - the governance model of this project
@@ -66,7 +66,6 @@ Note: Some modern features (like C++20 ranges or filesystem support) may be disa
        | Clang 20.1.1                                 | x86_64       | Ubuntu 22.04.1 LTS                | GitHub    |
        | Clang 20.1.8 with GNU-like command-line      | x86_64       | Windows Server 2022 (Build 20348) | GitHub    |
        | Clang 21.1.8                                 | x86_64       | Ubuntu 22.04.1 LTS                | GitHub    |
        | Clang 22.1.8                                 | x86_64       | Ubuntu 22.04.1 LTS                | GitHub    |
        | CUDA 11.8.0 (nvcc)                           | x86_64       | Ubuntu 22.04 LTS                  | GitHub    |
        | CUDA 12.1.1 (nvcc)                           | x86_64       | Ubuntu 22.04 LTS                  | GitHub    |
        | CUDA 12.6.3 (nvcc)                           | x86_64       | Ubuntu 22.04 LTS                  | GitHub    |
@@ -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 +1,15 @@
 #include <iostream>
 #include <nlohmann/json.hpp>
 using byte_container_with_subtype = nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>>;
 int main()
 {
    byte_container_with_subtype c1({0xca, 0xfe});
    byte_container_with_subtype c2({0xca, 0xfe});
    byte_container_with_subtype c3({0xca, 0xfe}, 42);
    std::cout << std::boolalpha
              << "c1 == c2: " << (c1 == c2) << '\n'
              << "c1 == c3: " << (c1 == c3) << std::endl;
 }
@@ -0,0 +1,2 @@
 c1 == c2: true
 c1 == c3: false
@@ -0,0 +1,15 @@
 #include <iostream>
 #include <nlohmann/json.hpp>
 using byte_container_with_subtype = nlohmann::byte_container_with_subtype<std::vector<std::uint8_t>>;
 int main()
 {
    byte_container_with_subtype c1({0xca, 0xfe});
    byte_container_with_subtype c2({0xca, 0xfe});
    byte_container_with_subtype c3({0xca, 0xfe}, 42);
    std::cout << std::boolalpha
              << "c1 != c2: " << (c1 != c2) << '\n'
              << "c1 != c3: " << (c1 != c3) << std::endl;
 }
@@ -0,0 +1,2 @@
 c1 != c2: false
 c1 != c3: 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;
 }
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
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`