Extend memcpy fast path to sized sentinels (e.g. std::counted_iterator)

Extend the memcpy fast path in iterator_input_adapter to sized sentinels of a different type, not just same-type iterator pairs. std::counted_iterator paired with std::default_sentinel_t already satisfies std::contiguous_iterator and std::sized_sentinel_for, so std::ranges::distance (C++20) lets that combination reach the fast path too, instead of silently falling back to the byte-by-byte path. - iterator_is_contiguous now also allows std::sized_sentinel_for<SentinelType, IteratorType> under C++20, gated the same way as the existing std::contiguous_iterator detection. - get_elements_impl's fast path uses std::ranges::distance under C++20 (works for both same-type and sized-sentinel pairs) and falls back to std::distance pre-C++20, where SentinelType is always IteratorType. - Add a C++20-only test exercising json::parse/accept with std::counted_iterator + std::default_sentinel_t. - Document std::default_sentinel_t + std::counted_iterator as a SentinelType example across parse.md, accept.md, sax_parse.md, and the five from_*.md pages, replacing an earlier ambiguously worded bullet. Addresses review feedback: https://github.com/nlohmann/json/pull/5265#discussion_r3564237584 Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Fix clang-tidy misc-const-correctness in heterogeneous sentinel test
2026-07-25 20:04:54 +00:00 · 2026-07-11 16:26:09 +02:00 · 2026-07-11 10:06:11 +02:00 · 2026-07-11 00:10:23 +02:00 · 2026-07-10 23:25:21 +02:00 · 2026-07-10 23:15:17 +02:00
30 changed files with 80 additions and 852 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
@@ -39,14 +39,14 @@ jobs:
          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
@@ -32,20 +32,20 @@ jobs:
        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@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+      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@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+      uses: github/codeql-action/autobuild@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3

    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+      uses: github/codeql-action/analyze@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
@@ -22,7 +22,7 @@ jobs:
          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'
@@ -32,7 +32,7 @@ jobs:
          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@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
        with:
          sarif_file: ${{github.workspace}}/flawfinder_results.sarif
@@ -26,7 +26,7 @@ jobs:
      DEVELOPER_DIR: /Applications/Xcode_${{ 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
@@ -31,7 +31,7 @@ jobs:
        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
@@ -41,7 +41,7 @@ jobs:
          egress-policy: audit

      - name: "Checkout code"
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false

@@ -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@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
        with:
          sarif_file: results.sarif
@@ -37,7 +37,7 @@ jobs:
          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@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
        with:
          sarif_file: semgrep.sarif
        if: always()
@@ -20,7 +20,7 @@ jobs:
        with:
          egress-policy: audit

-      - uses: actions/stale@1e223db275d687790206a7acac4d1a11bd6fe629 # v10.4.0
+      - uses: actions/stale@eb5cf3af3ac0a1aa4c9c45633dd1ae542a27a899 # v10.3.0
        with:
          stale-issue-label: 'state: stale'
          stale-pr-label: 'state: stale'
@@ -21,7 +21,7 @@ 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
@@ -43,7 +43,7 @@ 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
@@ -66,7 +66,7 @@ jobs:

      - 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
@@ -85,7 +85,7 @@ 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
@@ -104,7 +104,7 @@ 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
@@ -122,7 +122,7 @@ jobs:
        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
@@ -172,7 +172,7 @@ 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++-${{ matrix.compiler }}
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
@@ -190,7 +190,7 @@ jobs:
        compiler: ['7', '8', '9', '10', '11', '12', '13', '14', '15', 'latest']
    container: gcc:${{ 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
@@ -207,7 +207,7 @@ jobs:
        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:${{ matrix.compiler }}
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
@@ -227,7 +227,7 @@ jobs:
      matrix:
        standard: [11, 14, 17, 20, 23, 26]
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
@@ -247,7 +247,7 @@ jobs:
    steps:
      - name: Install git and unzip
        run: apt-get update ; apt-get install -y git unzip
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Get latest CMake and ninja
@@ -274,7 +274,7 @@ jobs:
        cuda: ['11.8.0', '12.1.1', '12.6.3']
    container: nvidia/cuda:${{ 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
@@ -291,7 +291,7 @@ 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
@@ -320,7 +320,7 @@ 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
@@ -337,7 +337,7 @@ 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@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
@@ -349,7 +349,7 @@ 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@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Run CMake
@@ -367,7 +367,7 @@ jobs:

      - 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
@@ -388,7 +388,7 @@ jobs:
        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
@@ -86,7 +86,7 @@ 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@f5b8fbb4d77cec1acc5a5f9f0df4beffaf5d98d9 # v4.3.4
      - name: Set extra CXX_FLAGS for latest std_version
@@ -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
@@ -173,7 +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
@@ -186,7 +186,7 @@ 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
@@ -51,38 +51,6 @@ represent a byte array in modern C++.

 The default values for `BinaryType` is `#!cpp std::vector<std::uint8_t>`.

-#### Custom BinaryType behavior
-
-When a custom `BinaryType` is configured (other than the default `#!cpp std::vector<std::uint8_t>`), you can assign
-values of that type directly to a `basic_json` instance, and they will automatically be recognized as binary values
-rather than arrays:
-
-```cpp
-using custom_json = nlohmann::basic_json<
-    nlohmann::ordered_map,  // ObjectType
-    std::vector,            // ArrayType
-    std::string,            // StringType
-    bool,                   // BooleanType
-    std::int64_t,           // NumberIntegerType
-    std::uint64_t,          // NumberUnsignedType
-    double,                 // NumberFloatType
-    std::allocator,         // AllocatorType
-    nlohmann::adl_serializer,
-    std::vector<std::byte>  // Custom BinaryType
->;
-
-std::vector<std::byte> data{std::byte{1}, std::byte{2}, std::byte{3}};
-custom_json j = data;  // Creates a binary value, not an array
-assert(j.is_binary());
-
-// Round-tripping works seamlessly
-auto extracted = j.get<std::vector<std::byte>>();
-assert(extracted == data);
-```
-
-This automatic type detection is a convenience feature that only applies to custom (non-default) `BinaryType` configurations.
-The default `nlohmann::json` continues to treat `#!cpp std::vector<std::uint8_t>` as arrays for backward compatibility.
-
 #### Storage

 Binary Arrays are stored as pointers in a `basic_json` type. That is, for any access to array values, a pointer of the
@@ -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
-    library from source — see the pre-installed-package caveat on that page.
+    which defines `JSON_DIAGNOSTICS` accordingly.

 ## Examples

@@ -47,28 +47,6 @@ json j = {{"one", 1}, {"two", 2}};
 auto m = j.get<std::map<std::string, int>>();  // {{"one", 1}, {"two", 2}}
 ```

-`#!cpp std::pair` and `#!cpp std::tuple` are also supported, converting positionally to and from a JSON array:
-
-```cpp
-json j = {1.0, "hello", 42};
-auto t = j.get<std::tuple<double, std::string, int>>();  // {1.0, "hello", 42}
-```
-
-!!! info "Extracting references into a tuple"
-
-    A tuple type may also hold references (e.g. `#!cpp std::tuple<double&, std::string&>`) to avoid copying: `get`
-    then returns a tuple of references pointing directly at the elements stored inside the `basic_json` array,
-    rather than a tuple of copies:
-
-    ```cpp
-    json j = {1.0, "hello"};
-    auto refs = j.get<std::tuple<double&, std::string&>>();
-    std::get<1>(refs) = "world";  // modifies j[1] in place
-    ```
-
-    A referenced type must be one the library actually stores (or an arithmetic type it can convert to/from);
-    otherwise this is a compile error.
-
 ## Implicit conversions

 By default, a JSON value implicitly converts to a compatible C++ type, so the explicit `get` call can often be omitted:
@@ -158,20 +136,6 @@ std::vector<int> numbers = {1, 2, 3};
 json j = numbers;   // [1,2,3]
 ```

-!!! info "Constructing from a C++20 range view"
-
-    A `json` array can also be constructed directly from a C++20 range view (`std::ranges::view`), such as the result
-    of `std::views::filter` or `std::views::transform` -- no intermediate container is needed:
-
-    ```cpp
-    std::vector<int> nums{1, 2, 37, 42, 21};
-    auto filtered = nums | std::views::filter([](int i) { return i > 10; });
-    json j(filtered);   // [37,42,21]
-    ```
-
-    This requires [`JSON_HAS_RANGES`](../api/macros/json_has_ranges.md) to be enabled and is unavailable on MinGW due
-    to incomplete C++20 ranges support there.
-
 ## Your own types

 The conversions above are built in for standard types. To make the same syntax work for **your own** types, provide
@@ -135,31 +135,6 @@ Enable CI build targets. The exact targets are used during the several CI steps

 Enable [extended diagnostic messages](../home/exceptions.md#extended-diagnostic-messages) by defining macro [`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md). This option is `OFF` by default.

-!!! warning "Does not apply to a pre-installed package"
-
-    This option only takes effect when building nlohmann/json from source as part of your own
-    CMake project (e.g. via [`FetchContent`](#fetchcontent) or [`add_subdirectory`](#external)).
-    It has **no effect** on a package that was already built and installed elsewhere (Homebrew,
-    vcpkg, a system package, etc.) — the resulting compile definition is baked into the exported
-    `nlohmann_jsonTargets.cmake` at install time, and `set(JSON_Diagnostics ON)` before
-    `find_package()` does not change it (verified against the Homebrew-installed package: the
-    exported target still carries a fixed `$<$<BOOL:OFF>:JSON_DIAGNOSTICS=1>`, regardless of any
-    variable set in the consuming project).
-
-    To enable extended diagnostics for a pre-installed package, override the imported target's
-    property directly after `find_package()`:
-
-    ```cmake
-    find_package(nlohmann_json REQUIRED)
-    set_target_properties(nlohmann_json::nlohmann_json PROPERTIES
-        INTERFACE_COMPILE_DEFINITIONS "JSON_DIAGNOSTICS=1")
-    ```
-
-    This only works cleanly when your project is the sole consumer of that imported target. If
-    nlohmann_json is pulled in from more than one place in your dependency graph with different
-    `JSON_DIAGNOSTICS` values, you may see a `"JSON_DIAGNOSTICS" redefined` compiler error, since
-    conflicting `-D` flags can end up on the same compile command line.
-
 ### `JSON_Diagnostic_Positions`

 Enable position diagnostics by defining macro [`JSON_DIAGNOSTIC_POSITIONS`](../api/macros/json_diagnostic_positions.md). This option is `OFF` by default.
@@ -930,12 +930,6 @@ If you are using [CocoaPods](https://cocoapods.org), you can use the library by
 to your podfile (see [an example](https://bitbucket.org/benman/nlohmann_json-cocoapod/src/master/)). Please file issues
 [here](https://bitbucket.org/benman/nlohmann_json-cocoapod/issues?status=new&status=open).

-## npm
-
-This project does not publish an official [npm](https://www.npmjs.com) 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. Use one of the package managers listed above, or integrate the single header directly.
-
 ## ESP-IDF and PlatformIO

 There is no official package published to the [ESP-IDF Component Registry](https://components.espressif.com) or the
@@ -19,7 +19,6 @@
 #include <unordered_map> // unordered_map
 #include <utility> // pair, declval
 #include <valarray> // valarray
-#include <vector> // vector

 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
@@ -333,7 +332,6 @@ template < typename BasicJsonType, typename ConstructibleArrayType,
               !is_constructible_object_type<BasicJsonType, ConstructibleArrayType>::value&&
               !is_constructible_string_type<BasicJsonType, ConstructibleArrayType>::value&&
               !std::is_same<ConstructibleArrayType, typename BasicJsonType::binary_t>::value&&
-               !is_compatible_binary_type<BasicJsonType, ConstructibleArrayType>::value&&
               !is_basic_json<ConstructibleArrayType>::value,
               int > = 0 >
 auto from_json(const BasicJsonType& j, ConstructibleArrayType& arr)
@@ -379,25 +377,6 @@ inline void from_json(const BasicJsonType& j, typename BasicJsonType::binary_t&
    bin = *j.template get_ptr<const typename BasicJsonType::binary_t*>();
 }

-template < typename BasicJsonType, typename CompatibleArrayType,
-           enable_if_t < is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value,
-                         int > = 0 >
-inline void from_json(const BasicJsonType& j, CompatibleArrayType& bin)
-{
-    if (j.is_binary())
-    {
-        bin = static_cast<CompatibleArrayType>(*j.template get_ptr<const typename BasicJsonType::binary_t*>());
-    }
-    else if (j.is_array())
-    {
-        from_json_array_impl(j, bin, priority_tag<3> {});
-    }
-    else
-    {
-        JSON_THROW(type_error::create(302, concat("type must be binary or array, but is ", j.type_name()), &j));
-    }
-}
-
 template<typename BasicJsonType, typename ConstructibleObjectType,
         enable_if_t<is_constructible_object_type<BasicJsonType, ConstructibleObjectType>::value, int> = 0>
 inline void from_json(const BasicJsonType& j, ConstructibleObjectType& obj)
@@ -177,11 +177,8 @@ struct external_constructor<value_t::array>
    }

    template < typename BasicJsonType, typename CompatibleArrayType,
-               enable_if_t < !std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-                             && !is_compatible_range_view<CompatibleArrayType>::value
-#endif
-                             , int > = 0 >
+               enable_if_t < !std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value,
+                             int > = 0 >
    static void construct(BasicJsonType& j, const CompatibleArrayType& arr)
    {
        using std::begin;
@@ -221,25 +218,6 @@ struct external_constructor<value_t::array>
        j.set_parents();
        j.assert_invariant();
    }
-
-    // std::ranges does not work properly on MinGW due to incomplete C++20 support
-    // see https://github.com/nlohmann/json/issues/4916
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-    template<typename BasicJsonType, typename CompatibleArrayType,
-             enable_if_t<is_compatible_range_view<std::remove_cvref_t<CompatibleArrayType>>::value, int> = 0>
-    static void construct(BasicJsonType& j, CompatibleArrayType && arr)
-    {
-        j.m_data.m_value.destroy(j.m_data.m_type);
-        j.m_data.m_type = value_t::array;
-        j.m_data.m_value = value_t::array;
-        for (auto&& x : std::forward<CompatibleArrayType>(arr))
-        {
-            j.m_data.m_value.array->push_back(x);
-            j.set_parent(j.m_data.m_value.array->back());
-        }
-        j.assert_invariant();
-    }
-#endif
 };

 template<>
@@ -377,44 +355,19 @@ template < typename BasicJsonType, typename CompatibleArrayType,
                         !is_compatible_object_type<BasicJsonType, CompatibleArrayType>::value&&
                         !is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value&&
                         !std::is_same<typename BasicJsonType::binary_t, CompatibleArrayType>::value&&
-                         !is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value&&
-                         !is_basic_json<CompatibleArrayType>::value
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-    && !is_compatible_range_view<CompatibleArrayType>::value
-#endif
-                         ,
+                         !is_basic_json<CompatibleArrayType>::value,
                         int > = 0 >
 inline void to_json(BasicJsonType& j, const CompatibleArrayType& arr)
 {
    external_constructor<value_t::array>::construct(j, arr);
 }

-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-template < typename BasicJsonType, typename T,
-           enable_if_t < is_compatible_range_view<std::remove_cvref_t<T>>::value
-                         && !is_compatible_string_type<BasicJsonType, std::remove_cvref_t<T>>::value
-                         && !is_compatible_object_type<BasicJsonType, std::remove_cvref_t<T>>::value
-                         && !is_basic_json<std::remove_cvref_t<T>>::value, int > = 0 >
-inline void to_json(BasicJsonType& j, T && arr)
-{
-    external_constructor<value_t::array>::construct(j, std::forward<T>(arr));
-}
-#endif
-
 template<typename BasicJsonType>
 inline void to_json(BasicJsonType& j, const typename BasicJsonType::binary_t& bin)
 {
    external_constructor<value_t::binary>::construct(j, bin);
 }

-template < typename BasicJsonType, typename CompatibleArrayType,
-           enable_if_t < is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value,
-                         int > = 0 >
-inline void to_json(BasicJsonType& j, const CompatibleArrayType& bin)
-{
-    external_constructor<value_t::binary>::construct(j, typename BasicJsonType::binary_t(bin));
-}
-
 template<typename BasicJsonType, typename T,
         enable_if_t<std::is_convertible<T, BasicJsonType>::value, int> = 0>
 inline void to_json(BasicJsonType& j, const std::valarray<T>& arr)
@@ -163,39 +163,12 @@ class binary_reader
    // BSON //
    //////////

-    /*!
-    @brief Validate a BSON document's declared size against the bytes read.
-
-    A BSON document starts with an int32 that counts its own total length in
-    bytes, including that prefix and the trailing 0x00. The reader is driven
-    by the terminator rather than the declared length, so without this check a
-    nested document could declare a length that disagrees with where its
-    terminator actually falls and quietly hand the bytes in between to the
-    enclosing document. A well-formed document is at least 5 bytes (the prefix
-    plus the terminator); the equality also rejects those impossible sizes,
-    since at least 5 bytes are always consumed.
-
-    @param[in] document_start  value of chars_read before the size prefix
-    @param[in] document_size   the declared document size
-    @return whether the declared size matches the number of bytes read
-    */
-    bool check_bson_document_size(const std::size_t document_start, const std::int32_t document_size)
-    {
-        if (JSON_HEDLEY_UNLIKELY(document_size < 0 || static_cast<std::size_t>(document_size) != chars_read - document_start))
-        {
-            return sax->parse_error(chars_read, get_token_string(), parse_error::create(112, chars_read,
-                                    exception_message(input_format_t::bson, concat("document size ", std::to_string(document_size), " does not match the number of bytes read (", std::to_string(chars_read - document_start), ")"), "document"), nullptr));
-        }
-        return true;
-    }
-
    /*!
    @brief Reads in a BSON-object and passes it to the SAX-parser.
    @return whether a valid BSON-value was passed to the SAX parser
    */
    bool parse_bson_internal()
    {
-        const std::size_t document_start = chars_read;
        std::int32_t document_size{};
        get_number<std::int32_t, true>(input_format_t::bson, document_size);

@@ -209,11 +182,6 @@ class binary_reader
            return false;
        }

-        if (JSON_HEDLEY_UNLIKELY(!check_bson_document_size(document_start, document_size)))
-        {
-            return false;
-        }
-
        return sax->end_object();
    }

@@ -429,7 +397,6 @@ class binary_reader
    */
    bool parse_bson_array()
    {
-        const std::size_t document_start = chars_read;
        std::int32_t document_size{};
        get_number<std::int32_t, true>(input_format_t::bson, document_size);

@@ -443,11 +410,6 @@ class binary_reader
            return false;
        }

-        if (JSON_HEDLEY_UNLIKELY(!check_bson_document_size(document_start, document_size)))
-        {
-            return false;
-        }
-
        return sax->end_array();
    }

@@ -1884,29 +1846,6 @@ class binary_reader
        return get_ubjson_value(get_char ? get_ignore_noop() : current);
    }

-    /*!
-    @brief reject a negative UBJSON/BJData string length
-
-    String and key lengths are written with signed integer markers (i, I, l,
-    L). A negative value is malformed; without this check get_string() would
-    silently treat it as an empty string and leave the following bytes to be
-    misread as the next value. This mirrors the non-negative check the
-    optimized-container count path already performs in get_ubjson_size_value.
-
-    @param[in] len  the string length read from the input
-    @return whether the length is valid (non-negative)
-    */
-    template<typename NumberType>
-    bool check_ubjson_string_length(const NumberType len)
-    {
-        if (JSON_HEDLEY_UNLIKELY(len < 0))
-        {
-            return sax->parse_error(chars_read, get_token_string(), parse_error::create(113, chars_read,
-                                    exception_message(input_format, "string length must not be negative", "string"), nullptr));
-        }
-        return true;
-    }
-
    /*!
    @brief reads a UBJSON string

@@ -1944,25 +1883,25 @@ class binary_reader
            case 'i':
            {
                std::int8_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'I':
            {
                std::int16_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'l':
            {
                std::int32_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'L':
            {
                std::int64_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'u':
@@ -395,30 +395,17 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
            }
            else
            {
-                // A supplementary code point is a high surrogate (0xD800..0xDBFF)
-                // followed by a low surrogate (0xDC00..0xDFFF). A lone low
-                // surrogate, a high surrogate at the end of the input, or a high
-                // surrogate followed by any other unit is malformed UTF-16. In
-                // that case the offending unit is passed through unchanged so the
-                // UTF-8 decoder rejects it, matching how \uXXXX surrogate escapes
-                // are handled in the lexer.
-                bool valid_pair = false;
-                if (wc <= 0xDBFF && JSON_HEDLEY_UNLIKELY(!input.empty()))
+                if (JSON_HEDLEY_UNLIKELY(!input.empty()))
                {
                    const auto wc2 = static_cast<unsigned int>(input.get_character());
-                    if (0xDC00 <= wc2 && wc2 <= 0xDFFF)
-                    {
-                        const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
-                        utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
-                        utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
-                        utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
-                        utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
-                        utf8_bytes_filled = 4;
-                        valid_pair = true;
-                    }
+                    const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
+                    utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
+                    utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
+                    utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                    utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                    utf8_bytes_filled = 4;
                }
-
-                if (!valid_pair)
+                else
                {
                    utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(wc);
                    utf8_bytes_filled = 1;
@@ -13,15 +13,11 @@
 #include <tuple> // tuple
 #include <type_traits> // false_type, is_constructible, is_integral, is_same, true_type
 #include <utility> // declval
-#include <vector> // vector
 #if defined(__cpp_lib_byte) && __cpp_lib_byte >= 201603L
    #include <cstddef> // byte
 #endif
 #include <nlohmann/detail/iterators/iterator_traits.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
-#ifdef JSON_HAS_CPP_17
-    #include <optional> // optional
-#endif
 #include <nlohmann/detail/meta/call_std/begin.hpp>
 #include <nlohmann/detail/meta/call_std/end.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
@@ -454,51 +450,6 @@ struct is_constructible_string_type
        value_type_t, laundered_type >>::value;
 };

-// Forward declarations: iteration_proxy.hpp includes this file, so we cannot
-// include it here.
-template<typename IteratorType> class iteration_proxy;
-template<typename IteratorType> class iteration_proxy_value;
-
-// Identifies nlohmann's internal iteration-proxy types. These must be excluded
-// before evaluating any std::ranges concept to avoid circular constraints.
-template<typename T> struct is_iteration_proxy_type : std::false_type {};
-template<typename T> struct is_iteration_proxy_type<iteration_proxy<T>>       : std::true_type {};
-template<typename T> struct is_iteration_proxy_type<iteration_proxy_value<T>> : std::true_type {};
-
-// In C++26, std::optional satisfies std::ranges::view; exclude it so the
-// range-view overload does not hijack the optional serializer.
-#ifdef JSON_HAS_CPP_17
-template<typename T> struct is_range_view_optional_type : std::false_type {};
-template<typename T> struct is_range_view_optional_type<std::optional<T>> : std::true_type {};
-#else
-template<typename T> struct is_range_view_optional_type : std::false_type {};
-#endif
-
-// std::ranges does not work properly on MinGW due to incomplete C++20 support
-// see https://github.com/nlohmann/json/issues/4916
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-
-// SafeToCheck guards against types that trigger circular constraints when
-// std::ranges::view<T> is evaluated on GCC 12 / libstdc++ 12:
-//   - iteration_proxy / iteration_proxy_value directly
-//   - views wrapping the above (e.g. owning_view<iteration_proxy<...>>)
-//   - views wrapping basic_json (e.g. ref_view<json>) — same circularity
-//     via json's constructors → is_compatible_array_type → here
-// nlohmann's plain range_value_t (iterator_traits-based) is safe to call
-// before any std::ranges concept is touched, so we use it for the checks.
-template < typename T, bool SafeToCheck =
-           !is_iteration_proxy_type<T>::value &&
-           !is_iteration_proxy_type<detected_t<range_value_t, T>>::value &&
-           !is_basic_json<detected_t<range_value_t, T>>::value &&
-           !is_range_view_optional_type<T>::value >
-struct is_compatible_range_view : std::false_type {};
-
-template<typename T>
-struct is_compatible_range_view<T, true>
-    : std::bool_constant<std::ranges::view<T>> {};
-
-#endif
-
 template<typename BasicJsonType, typename CompatibleArrayType, typename = void>
 struct is_compatible_array_type_impl : std::false_type {};

@@ -510,38 +461,13 @@ struct is_compatible_array_type_impl <
    is_iterator_traits<iterator_traits<detected_t<iterator_t, CompatibleArrayType>>>::value&&
 // special case for types like std::filesystem::path whose iterator's value_type are themselves
 // c.f. https://github.com/nlohmann/json/pull/3073
-    !std::is_same<CompatibleArrayType, detected_t<range_value_t, CompatibleArrayType>>::value
-// When range-view support is enabled, std::ranges::view types (e.g. std::string_view,
-// filter_view) can match BOTH this iterator-based specialization AND the view-based one
-// below, causing ambiguity. Exclude views here so the two specializations are mutually
-// exclusive: this one handles plain iterable containers, the other handles views.
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-&& !is_compatible_range_view<CompatibleArrayType>::value
-#endif
-            >>
+    !std::is_same<CompatibleArrayType, detected_t<range_value_t, CompatibleArrayType>>::value >>
 {
    static constexpr bool value =
        is_constructible<BasicJsonType,
        range_value_t<CompatibleArrayType>>::value;
 };

-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-template<typename BasicJsonType, typename CompatibleArrayType>
-struct is_compatible_array_type_impl <
-    BasicJsonType, CompatibleArrayType,
-    enable_if_t < is_compatible_range_view<CompatibleArrayType>::value
-    && !std::is_same<detected_t<range_value_t, CompatibleArrayType>, char>::value
-    && !std::is_same<detected_t<range_value_t, CompatibleArrayType>, wchar_t>::value >>
-{
-    // CompatibleArrayType is a std::ranges::view here, so std::ranges::range_value_t
-    // is safe and correctly handles C++20 iterators that may lack classic iterator_traits.
-    static constexpr bool value =
-        is_constructible<BasicJsonType,
-        std::ranges::range_value_t<CompatibleArrayType>>::value;
-};
-#endif
-
-
 template<typename BasicJsonType, typename CompatibleArrayType>
 struct is_compatible_array_type
    : is_compatible_array_type_impl<BasicJsonType, CompatibleArrayType> {};
@@ -633,14 +559,6 @@ template<typename BasicJsonType, typename CompatibleType>
 struct is_compatible_type
    : is_compatible_type_impl<BasicJsonType, CompatibleType> {};

-template<typename BasicJsonType, typename CompatibleArrayType>
-struct is_compatible_binary_type
-{
-    static constexpr bool value =
-        std::is_same<typename BasicJsonType::binary_t::container_type, CompatibleArrayType>::value &&
-        !std::is_same<typename BasicJsonType::binary_t::container_type, std::vector<std::uint8_t>>::value;
-};
-
 template<typename BasicJsonType, typename CompatibleReferenceType>
 struct is_compatible_reference_type_impl
 {
@@ -189,7 +189,6 @@
 #include <unordered_map> // unordered_map
 #include <utility> // pair, declval
 #include <valarray> // valarray
-#include <vector> // vector

 // #include <nlohmann/detail/exceptions.hpp>
 //     __ _____ _____ _____
@@ -3593,7 +3592,6 @@ NLOHMANN_JSON_NAMESPACE_END
 #include <tuple> // tuple
 #include <type_traits> // false_type, is_constructible, is_integral, is_same, true_type
 #include <utility> // declval
-#include <vector> // vector
 #if defined(__cpp_lib_byte) && __cpp_lib_byte >= 201603L
    #include <cstddef> // byte
 #endif
@@ -3665,9 +3663,6 @@ NLOHMANN_JSON_NAMESPACE_END

 // #include <nlohmann/detail/macro_scope.hpp>

-#ifdef JSON_HAS_CPP_17
-    #include <optional> // optional
-#endif
 // #include <nlohmann/detail/meta/call_std/begin.hpp>
 //     __ _____ _____ _____
 //  __|  |   __|     |   | |  JSON for Modern C++
@@ -4217,51 +4212,6 @@ struct is_constructible_string_type
        value_type_t, laundered_type >>::value;
 };

-// Forward declarations: iteration_proxy.hpp includes this file, so we cannot
-// include it here.
-template<typename IteratorType> class iteration_proxy;
-template<typename IteratorType> class iteration_proxy_value;
-
-// Identifies nlohmann's internal iteration-proxy types. These must be excluded
-// before evaluating any std::ranges concept to avoid circular constraints.
-template<typename T> struct is_iteration_proxy_type : std::false_type {};
-template<typename T> struct is_iteration_proxy_type<iteration_proxy<T>>       : std::true_type {};
-template<typename T> struct is_iteration_proxy_type<iteration_proxy_value<T>> : std::true_type {};
-
-// In C++26, std::optional satisfies std::ranges::view; exclude it so the
-// range-view overload does not hijack the optional serializer.
-#ifdef JSON_HAS_CPP_17
-template<typename T> struct is_range_view_optional_type : std::false_type {};
-template<typename T> struct is_range_view_optional_type<std::optional<T>> : std::true_type {};
-#else
-template<typename T> struct is_range_view_optional_type : std::false_type {};
-#endif
-
-// std::ranges does not work properly on MinGW due to incomplete C++20 support
-// see https://github.com/nlohmann/json/issues/4916
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-
-// SafeToCheck guards against types that trigger circular constraints when
-// std::ranges::view<T> is evaluated on GCC 12 / libstdc++ 12:
-//   - iteration_proxy / iteration_proxy_value directly
-//   - views wrapping the above (e.g. owning_view<iteration_proxy<...>>)
-//   - views wrapping basic_json (e.g. ref_view<json>) — same circularity
-//     via json's constructors → is_compatible_array_type → here
-// nlohmann's plain range_value_t (iterator_traits-based) is safe to call
-// before any std::ranges concept is touched, so we use it for the checks.
-template < typename T, bool SafeToCheck =
-           !is_iteration_proxy_type<T>::value &&
-           !is_iteration_proxy_type<detected_t<range_value_t, T>>::value &&
-           !is_basic_json<detected_t<range_value_t, T>>::value &&
-           !is_range_view_optional_type<T>::value >
-struct is_compatible_range_view : std::false_type {};
-
-template<typename T>
-struct is_compatible_range_view<T, true>
-    : std::bool_constant<std::ranges::view<T>> {};
-
-#endif
-
 template<typename BasicJsonType, typename CompatibleArrayType, typename = void>
 struct is_compatible_array_type_impl : std::false_type {};

@@ -4273,38 +4223,13 @@ struct is_compatible_array_type_impl <
    is_iterator_traits<iterator_traits<detected_t<iterator_t, CompatibleArrayType>>>::value&&
 // special case for types like std::filesystem::path whose iterator's value_type are themselves
 // c.f. https://github.com/nlohmann/json/pull/3073
-    !std::is_same<CompatibleArrayType, detected_t<range_value_t, CompatibleArrayType>>::value
-// When range-view support is enabled, std::ranges::view types (e.g. std::string_view,
-// filter_view) can match BOTH this iterator-based specialization AND the view-based one
-// below, causing ambiguity. Exclude views here so the two specializations are mutually
-// exclusive: this one handles plain iterable containers, the other handles views.
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-&& !is_compatible_range_view<CompatibleArrayType>::value
-#endif
-            >>
+    !std::is_same<CompatibleArrayType, detected_t<range_value_t, CompatibleArrayType>>::value >>
 {
    static constexpr bool value =
        is_constructible<BasicJsonType,
        range_value_t<CompatibleArrayType>>::value;
 };

-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-template<typename BasicJsonType, typename CompatibleArrayType>
-struct is_compatible_array_type_impl <
-    BasicJsonType, CompatibleArrayType,
-    enable_if_t < is_compatible_range_view<CompatibleArrayType>::value
-    && !std::is_same<detected_t<range_value_t, CompatibleArrayType>, char>::value
-    && !std::is_same<detected_t<range_value_t, CompatibleArrayType>, wchar_t>::value >>
-{
-    // CompatibleArrayType is a std::ranges::view here, so std::ranges::range_value_t
-    // is safe and correctly handles C++20 iterators that may lack classic iterator_traits.
-    static constexpr bool value =
-        is_constructible<BasicJsonType,
-        std::ranges::range_value_t<CompatibleArrayType>>::value;
-};
-#endif
-
-
 template<typename BasicJsonType, typename CompatibleArrayType>
 struct is_compatible_array_type
    : is_compatible_array_type_impl<BasicJsonType, CompatibleArrayType> {};
@@ -4396,14 +4321,6 @@ template<typename BasicJsonType, typename CompatibleType>
 struct is_compatible_type
    : is_compatible_type_impl<BasicJsonType, CompatibleType> {};

-template<typename BasicJsonType, typename CompatibleArrayType>
-struct is_compatible_binary_type
-{
-    static constexpr bool value =
-        std::is_same<typename BasicJsonType::binary_t::container_type, CompatibleArrayType>::value &&
-        !std::is_same<typename BasicJsonType::binary_t::container_type, std::vector<std::uint8_t>>::value;
-};
-
 template<typename BasicJsonType, typename CompatibleReferenceType>
 struct is_compatible_reference_type_impl
 {
@@ -5547,7 +5464,6 @@ template < typename BasicJsonType, typename ConstructibleArrayType,
               !is_constructible_object_type<BasicJsonType, ConstructibleArrayType>::value&&
               !is_constructible_string_type<BasicJsonType, ConstructibleArrayType>::value&&
               !std::is_same<ConstructibleArrayType, typename BasicJsonType::binary_t>::value&&
-               !is_compatible_binary_type<BasicJsonType, ConstructibleArrayType>::value&&
               !is_basic_json<ConstructibleArrayType>::value,
               int > = 0 >
 auto from_json(const BasicJsonType& j, ConstructibleArrayType& arr)
@@ -5593,25 +5509,6 @@ inline void from_json(const BasicJsonType& j, typename BasicJsonType::binary_t&
    bin = *j.template get_ptr<const typename BasicJsonType::binary_t*>();
 }

-template < typename BasicJsonType, typename CompatibleArrayType,
-           enable_if_t < is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value,
-                         int > = 0 >
-inline void from_json(const BasicJsonType& j, CompatibleArrayType& bin)
-{
-    if (j.is_binary())
-    {
-        bin = static_cast<CompatibleArrayType>(*j.template get_ptr<const typename BasicJsonType::binary_t*>());
-    }
-    else if (j.is_array())
-    {
-        from_json_array_impl(j, bin, priority_tag<3> {});
-    }
-    else
-    {
-        JSON_THROW(type_error::create(302, concat("type must be binary or array, but is ", j.type_name()), &j));
-    }
-}
-
 template<typename BasicJsonType, typename ConstructibleObjectType,
         enable_if_t<is_constructible_object_type<BasicJsonType, ConstructibleObjectType>::value, int> = 0>
 inline void from_json(const BasicJsonType& j, ConstructibleObjectType& obj)
@@ -6308,11 +6205,8 @@ struct external_constructor<value_t::array>
    }

    template < typename BasicJsonType, typename CompatibleArrayType,
-               enable_if_t < !std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-                             && !is_compatible_range_view<CompatibleArrayType>::value
-#endif
-                             , int > = 0 >
+               enable_if_t < !std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value,
+                             int > = 0 >
    static void construct(BasicJsonType& j, const CompatibleArrayType& arr)
    {
        using std::begin;
@@ -6352,25 +6246,6 @@ struct external_constructor<value_t::array>
        j.set_parents();
        j.assert_invariant();
    }
-
-    // std::ranges does not work properly on MinGW due to incomplete C++20 support
-    // see https://github.com/nlohmann/json/issues/4916
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-    template<typename BasicJsonType, typename CompatibleArrayType,
-             enable_if_t<is_compatible_range_view<std::remove_cvref_t<CompatibleArrayType>>::value, int> = 0>
-    static void construct(BasicJsonType& j, CompatibleArrayType && arr)
-    {
-        j.m_data.m_value.destroy(j.m_data.m_type);
-        j.m_data.m_type = value_t::array;
-        j.m_data.m_value = value_t::array;
-        for (auto&& x : std::forward<CompatibleArrayType>(arr))
-        {
-            j.m_data.m_value.array->push_back(x);
-            j.set_parent(j.m_data.m_value.array->back());
-        }
-        j.assert_invariant();
-    }
-#endif
 };

 template<>
@@ -6508,44 +6383,19 @@ template < typename BasicJsonType, typename CompatibleArrayType,
                         !is_compatible_object_type<BasicJsonType, CompatibleArrayType>::value&&
                         !is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value&&
                         !std::is_same<typename BasicJsonType::binary_t, CompatibleArrayType>::value&&
-                         !is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value&&
-                         !is_basic_json<CompatibleArrayType>::value
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-    && !is_compatible_range_view<CompatibleArrayType>::value
-#endif
-                         ,
+                         !is_basic_json<CompatibleArrayType>::value,
                         int > = 0 >
 inline void to_json(BasicJsonType& j, const CompatibleArrayType& arr)
 {
    external_constructor<value_t::array>::construct(j, arr);
 }

-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-template < typename BasicJsonType, typename T,
-           enable_if_t < is_compatible_range_view<std::remove_cvref_t<T>>::value
-                         && !is_compatible_string_type<BasicJsonType, std::remove_cvref_t<T>>::value
-                         && !is_compatible_object_type<BasicJsonType, std::remove_cvref_t<T>>::value
-                         && !is_basic_json<std::remove_cvref_t<T>>::value, int > = 0 >
-inline void to_json(BasicJsonType& j, T && arr)
-{
-    external_constructor<value_t::array>::construct(j, std::forward<T>(arr));
-}
-#endif
-
 template<typename BasicJsonType>
 inline void to_json(BasicJsonType& j, const typename BasicJsonType::binary_t& bin)
 {
    external_constructor<value_t::binary>::construct(j, bin);
 }

-template < typename BasicJsonType, typename CompatibleArrayType,
-           enable_if_t < is_compatible_binary_type<BasicJsonType, CompatibleArrayType>::value,
-                         int > = 0 >
-inline void to_json(BasicJsonType& j, const CompatibleArrayType& bin)
-{
-    external_constructor<value_t::binary>::construct(j, typename BasicJsonType::binary_t(bin));
-}
-
 template<typename BasicJsonType, typename T,
         enable_if_t<std::is_convertible<T, BasicJsonType>::value, int> = 0>
 inline void to_json(BasicJsonType& j, const std::valarray<T>& arr)
@@ -7382,30 +7232,17 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
            }
            else
            {
-                // A supplementary code point is a high surrogate (0xD800..0xDBFF)
-                // followed by a low surrogate (0xDC00..0xDFFF). A lone low
-                // surrogate, a high surrogate at the end of the input, or a high
-                // surrogate followed by any other unit is malformed UTF-16. In
-                // that case the offending unit is passed through unchanged so the
-                // UTF-8 decoder rejects it, matching how \uXXXX surrogate escapes
-                // are handled in the lexer.
-                bool valid_pair = false;
-                if (wc <= 0xDBFF && JSON_HEDLEY_UNLIKELY(!input.empty()))
+                if (JSON_HEDLEY_UNLIKELY(!input.empty()))
                {
                    const auto wc2 = static_cast<unsigned int>(input.get_character());
-                    if (0xDC00 <= wc2 && wc2 <= 0xDFFF)
-                    {
-                        const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
-                        utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
-                        utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
-                        utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
-                        utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
-                        utf8_bytes_filled = 4;
-                        valid_pair = true;
-                    }
+                    const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
+                    utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
+                    utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
+                    utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                    utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                    utf8_bytes_filled = 4;
                }
-
-                if (!valid_pair)
+                else
                {
                    utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(wc);
                    utf8_bytes_filled = 1;
@@ -10712,39 +10549,12 @@ class binary_reader
    // BSON //
    //////////

-    /*!
-    @brief Validate a BSON document's declared size against the bytes read.
-
-    A BSON document starts with an int32 that counts its own total length in
-    bytes, including that prefix and the trailing 0x00. The reader is driven
-    by the terminator rather than the declared length, so without this check a
-    nested document could declare a length that disagrees with where its
-    terminator actually falls and quietly hand the bytes in between to the
-    enclosing document. A well-formed document is at least 5 bytes (the prefix
-    plus the terminator); the equality also rejects those impossible sizes,
-    since at least 5 bytes are always consumed.
-
-    @param[in] document_start  value of chars_read before the size prefix
-    @param[in] document_size   the declared document size
-    @return whether the declared size matches the number of bytes read
-    */
-    bool check_bson_document_size(const std::size_t document_start, const std::int32_t document_size)
-    {
-        if (JSON_HEDLEY_UNLIKELY(document_size < 0 || static_cast<std::size_t>(document_size) != chars_read - document_start))
-        {
-            return sax->parse_error(chars_read, get_token_string(), parse_error::create(112, chars_read,
-                                    exception_message(input_format_t::bson, concat("document size ", std::to_string(document_size), " does not match the number of bytes read (", std::to_string(chars_read - document_start), ")"), "document"), nullptr));
-        }
-        return true;
-    }
-
    /*!
    @brief Reads in a BSON-object and passes it to the SAX-parser.
    @return whether a valid BSON-value was passed to the SAX parser
    */
    bool parse_bson_internal()
    {
-        const std::size_t document_start = chars_read;
        std::int32_t document_size{};
        get_number<std::int32_t, true>(input_format_t::bson, document_size);

@@ -10758,11 +10568,6 @@ class binary_reader
            return false;
        }

-        if (JSON_HEDLEY_UNLIKELY(!check_bson_document_size(document_start, document_size)))
-        {
-            return false;
-        }
-
        return sax->end_object();
    }

@@ -10978,7 +10783,6 @@ class binary_reader
    */
    bool parse_bson_array()
    {
-        const std::size_t document_start = chars_read;
        std::int32_t document_size{};
        get_number<std::int32_t, true>(input_format_t::bson, document_size);

@@ -10992,11 +10796,6 @@ class binary_reader
            return false;
        }

-        if (JSON_HEDLEY_UNLIKELY(!check_bson_document_size(document_start, document_size)))
-        {
-            return false;
-        }
-
        return sax->end_array();
    }

@@ -12433,29 +12232,6 @@ class binary_reader
        return get_ubjson_value(get_char ? get_ignore_noop() : current);
    }

-    /*!
-    @brief reject a negative UBJSON/BJData string length
-
-    String and key lengths are written with signed integer markers (i, I, l,
-    L). A negative value is malformed; without this check get_string() would
-    silently treat it as an empty string and leave the following bytes to be
-    misread as the next value. This mirrors the non-negative check the
-    optimized-container count path already performs in get_ubjson_size_value.
-
-    @param[in] len  the string length read from the input
-    @return whether the length is valid (non-negative)
-    */
-    template<typename NumberType>
-    bool check_ubjson_string_length(const NumberType len)
-    {
-        if (JSON_HEDLEY_UNLIKELY(len < 0))
-        {
-            return sax->parse_error(chars_read, get_token_string(), parse_error::create(113, chars_read,
-                                    exception_message(input_format, "string length must not be negative", "string"), nullptr));
-        }
-        return true;
-    }
-
    /*!
    @brief reads a UBJSON string

@@ -12493,25 +12269,25 @@ class binary_reader
            case 'i':
            {
                std::int8_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'I':
            {
                std::int16_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'l':
            {
                std::int32_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'L':
            {
                std::int64_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && get_string(input_format, len, result);
            }

            case 'u':
@@ -2721,19 +2721,6 @@ TEST_CASE("BJData")
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing BJData string: expected length type specification (U, i, u, I, m, l, M, L); last byte: 0x31", json::parse_error&);
            }

-            SECTION("negative length")
-            {
-                json _;
-
-                std::vector<uint8_t> const vi = {'S', 'i', 0xFF};
-                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vi), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing BJData string: string length must not be negative", json::parse_error&);
-                CHECK(json::from_bjdata(vi, true, false).is_discarded());
-
-                std::vector<uint8_t> const vl = {'S', 'l', 0xFF, 0xFF, 0xFF, 0xFF};
-                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vl), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing BJData string: string length must not be negative", json::parse_error&);
-                CHECK(json::from_bjdata(vl, true, false).is_discarded());
-            }
-
            SECTION("parse bjdata markers in ubjson")
            {
                // create a single-character string for all number types
@@ -854,62 +854,6 @@ TEST_CASE("Unsupported BSON input")
    CHECK(!json::sax_parse(bson, &scp, json::input_format_t::bson));
 }

-TEST_CASE("BSON document size mismatch")
-{
-    json _;
-
-    SECTION("top-level document declaring more bytes than it contains")
-    {
-        // empty object, but the length prefix claims 6 bytes instead of 5
-        std::vector<std::uint8_t> const input = {0x06, 0x00, 0x00, 0x00, 0x00};
-        CHECK_THROWS_WITH_AS(_ = json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 5: syntax error while parsing BSON document: document size 6 does not match the number of bytes read (5)", json::parse_error&);
-        CHECK(json::from_bson(input, true, false).is_discarded());
-    }
-
-    SECTION("top-level document with a negative size")
-    {
-        std::vector<std::uint8_t> const input = {0xFF, 0xFF, 0xFF, 0xFF, 0x00};
-        CHECK_THROWS_WITH_AS(_ = json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 5: syntax error while parsing BSON document: document size -1 does not match the number of bytes read (5)", json::parse_error&);
-        CHECK(json::from_bson(input, true, false).is_discarded());
-    }
-
-    SECTION("embedded document whose size disagrees with its terminator")
-    {
-        // the embedded document "d" declares 0x7FFFFFFF bytes but its 0x00
-        // terminator falls right after {"a":null}; the length prefix would
-        // otherwise let the following "h" element be read as a member of the
-        // enclosing document instead of "d"
-        std::vector<std::uint8_t> const input =
-        {
-            0x00, 0x00, 0x00, 0x00, // outer size
-            0x03, 'd', 0x00,        // entry: embedded document "d"
-            0xFF, 0xFF, 0xFF, 0x7F, //   embedded size 0x7FFFFFFF
-            0x0A, 'a', 0x00,        //   entry: null "a"
-            0x00,                   //   embedded end marker
-            0x08, 'h', 0x00, 0x01,  // entry: bool "h" = true
-            0x00                    // outer end marker
-        };
-        CHECK_THROWS_WITH_AS(_ = json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 15: syntax error while parsing BSON document: document size 2147483647 does not match the number of bytes read (8)", json::parse_error&);
-        CHECK(json::from_bson(input, true, false).is_discarded());
-    }
-
-    SECTION("embedded array whose size disagrees with its terminator")
-    {
-        // array [42] is 12 bytes, but the length prefix claims 13
-        std::vector<std::uint8_t> const input =
-        {
-            0x00, 0x00, 0x00, 0x00, // outer size
-            0x04, 'a', 0x00,        // entry: array "a"
-            0x0D, 0x00, 0x00, 0x00, //   array size 13 (real is 12)
-            0x10, '0', 0x00, 0x2A, 0x00, 0x00, 0x00, //   entry: int32 "0" = 42
-            0x00,                   //   array end marker
-            0x00                    // outer end marker
-        };
-        CHECK_THROWS_WITH_AS(_ = json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 19: syntax error while parsing BSON document: document size 13 does not match the number of bytes read (12)", json::parse_error&);
-        CHECK(json::from_bson(input, true, false).is_discarded());
-    }
-}
-
 TEST_CASE("BSON numerical data")
 {
    SECTION("number")
@@ -1782,21 +1782,6 @@ TEST_CASE("std::optional")
                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
        CHECK_THROWS_WITH_AS(std::optional<int>(j_null),
                             "[json.exception.type_error.302] type must be number, but is null", json::type_error&);
-
-        // Assignment goes through the same overload resolution as direct
-        // construction, so it throws for the same reason. This relies on
-        // basic_json's implicit conversion operator, so it only applies
-        // when JSON_USE_IMPLICIT_CONVERSIONS is enabled (the default).
-#if JSON_USE_IMPLICIT_CONVERSIONS
-        std::optional<std::string> opt_assign;
-        CHECK_THROWS_WITH_AS(opt_assign = j_null,
-                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
-#endif
-
-        // get_to() is the correct way to obtain std::nullopt from a JSON null.
-        std::optional<std::string> opt_get_to = "placeholder";
-        j_null.get_to(opt_get_to);
-        CHECK(opt_get_to == std::nullopt);
    }

    SECTION("string")
@@ -1136,40 +1136,6 @@ TEST_CASE("regression tests 2")
        CHECK((decoded == json_4804::array()));
    }

-    SECTION("discussion #4209 - custom BinaryType direct assignment and round-tripping")
-    {
-        // Test that assigning a custom BinaryType directly creates a binary value, not an array
-        const std::vector<std::byte> original{std::byte{1}, std::byte{2}, std::byte{3}};
-        const json_4804 j = original;
-        CHECK(j.is_binary());
-        CHECK(!j.is_array());
-
-        // Test round-tripping: extracting the binary value back as the custom container type
-        const auto extracted = j.get<std::vector<std::byte>>();
-        CHECK(extracted == original);
-
-        // Test that the default json alias behavior is unchanged: std::vector<uint8_t> -> array
-        const json default_json = std::vector<std::uint8_t> {1, 2, 3};
-        CHECK(default_json.is_array());
-        CHECK(!default_json.is_binary());
-    }
-
-    SECTION("discussion #4209 - custom BinaryType extraction from parsed array")
-    {
-        // Test that extracting a custom BinaryType from a parsed JSON array still works
-        // (not just from a binary-typed node)
-        const auto j = json_4804::parse("[1,2,3]");
-        CHECK(j.is_array());
-        CHECK(!j.is_binary());
-
-        // Extracting as custom BinaryType should work from arrays
-        const auto extracted = j.get<std::vector<std::byte>>();
-        CHECK(extracted.size() == 3);
-        CHECK(extracted[0] == std::byte{1});
-        CHECK(extracted[1] == std::byte{2});
-        CHECK(extracted[2] == std::byte{3});
-    }
-
    SECTION("issue #5046 - implicit conversion of return json to std::optional no longer implicit")
    {
        const json jval{};
@@ -1199,46 +1165,6 @@ TEST_CASE("regression tests 2")
    }
 #endif

-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-    SECTION("issue #4916 - constructing array from C++20 ranges view does not work")
-    {
-        std::vector<int> nums{1, 2, 37, 42, 21};
-        auto filteredNums = nums | std::views::filter([](int i)
-        {
-            return i > 10;
-        });
-        json const j(filteredNums);
-        CHECK(j.type() == json::value_t::array);
-        CHECK(j == json({37, 42, 21}));
-    }
-#endif
-
-    // owning_view is not available in libstdc++ < 12
-#if JSON_HAS_RANGES && !defined(__MINGW32__) && !(defined(__GLIBCXX__) && _GLIBCXX_RELEASE < 12)
-    SECTION("issue #4916 - constructing array from prvalue C++20 ranges view (owning_view)")
-    {
-        json const j(std::vector<int> {1, 2, 37, 42, 21} | std::views::filter([](int i)
-        {
-            return i > 10;
-        }));
-        CHECK(j.type() == json::value_t::array);
-        CHECK(j == json({37, 42, 21}));
-    }
-#endif
-
-#if JSON_HAS_RANGES && !defined(__MINGW32__)
-    SECTION("issue #4916 - constructing array from C++20 transform view (prvalue elements)")
-    {
-        std::vector<int> nums{1, 2, 3};
-        auto t = nums | std::views::transform([](int i) noexcept
-        {
-            return i * 2;
-        });
-        json const j(t);
-        CHECK(j.type() == json::value_t::array);
-        CHECK(j == json({2, 4, 6}));
-    }
-#endif
 }

 TEST_CASE_TEMPLATE("issue #4798 - nlohmann::json::to_msgpack() encode float NaN as double", T, double, float) // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
@@ -1862,31 +1862,6 @@ TEST_CASE("UBJSON")
                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(v), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing UBJSON string: expected length type specification (U, i, I, l, L); last byte: 0x31", json::parse_error&);
            }
-
-            SECTION("negative length")
-            {
-                json _;
-
-                std::vector<uint8_t> const vi = {'S', 'i', 0xFF};
-                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vi), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
-                CHECK(json::from_ubjson(vi, true, false).is_discarded());
-
-                std::vector<uint8_t> const vI = {'S', 'I', 0xFF, 0xFF};
-                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vI), "[json.exception.parse_error.113] parse error at byte 4: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
-                CHECK(json::from_ubjson(vI, true, false).is_discarded());
-
-                std::vector<uint8_t> const vl = {'S', 'l', 0xFF, 0xFF, 0xFF, 0xFF};
-                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vl), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
-                CHECK(json::from_ubjson(vl, true, false).is_discarded());
-
-                std::vector<uint8_t> const vL = {'S', 'L', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vL), "[json.exception.parse_error.113] parse error at byte 10: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
-                CHECK(json::from_ubjson(vL, true, false).is_discarded());
-
-                // a length of zero remains valid and yields an empty string
-                std::vector<uint8_t> const v0 = {'S', 'i', 0};
-                CHECK(json::from_ubjson(v0) == json(""));
-            }
        }

        SECTION("array")
@@ -216,16 +216,15 @@ TEST_CASE("Parse with heterogeneous iterator and sentinel types")
 // JSON_HAS_CPP_20 (do not remove; see note at top of file)
 TEST_CASE("Parse with std::counted_iterator and std::default_sentinel_t")
 {
-    using iterator_type = std::string::const_iterator;
    const std::string json_str = R"({"key":"value","array":[1,2,3]})";
-    const auto len = static_cast<std::iter_difference_t<iterator_type>>(json_str.size());
+    const auto len = static_cast<std::iter_difference_t<std::string::const_iterator>>(json_str.size());

-    const std::counted_iterator<iterator_type> first(json_str.begin(), len);
+    std::counted_iterator first(json_str.begin(), len);
    const json j = json::parse(first, std::default_sentinel);
    CHECK(j["key"] == "value");
    CHECK(j["array"].size() == 3);

-    const std::counted_iterator<iterator_type> first2(json_str.begin(), len);
+    std::counted_iterator first2(json_str.begin(), len);
    CHECK(json::accept(first2, std::default_sentinel));
 }
 #endif
@@ -53,27 +53,6 @@ TEST_CASE("wide strings")
            std::wstring const w = L"\"\xDBFF";
            json _;
            CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
-
-            // the exact message depends on the width of wchar_t: a 16-bit
-            // wchar_t passes the lone surrogate to the UTF-8 decoder unchanged
-            // (rejected as a single ill-formed byte at column 2), while a
-            // 32-bit wchar_t first encodes it as an ill-formed three-byte
-            // sequence (rejected one byte later, at column 3)
-            const char* const error_low_surrogate = sizeof(wchar_t) == 2
-                                                    ? "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'"
-                                                    : "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"\xED\xB0'";
-            const char* const error_high_surrogate = sizeof(wchar_t) == 2
-                ? "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'"
-                : "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"\xED\xA0'";
-
-            // a lone low surrogate cannot start a pair
-            CHECK_THROWS_WITH_AS(_ = json::parse(std::wstring{L'"', static_cast<wchar_t>(0xDC00), L'"'}), error_low_surrogate, json::parse_error&);
-            // a high surrogate followed by a non-low-surrogate unit is invalid
-            CHECK_THROWS_WITH_AS(_ = json::parse(std::wstring{L'"', static_cast<wchar_t>(0xD800), L'a', L'"'}), error_high_surrogate, json::parse_error&);
-            // a lone low surrogate must not swallow the following unit: pairing
-            // it with any second unit would produce valid UTF-8, so the error
-            // has to report an ill-formed byte at the surrogate's own position
-            CHECK_THROWS_WITH_AS(_ = json::parse(std::wstring{L'"', static_cast<wchar_t>(0xDC00), L'a', L'"'}), error_low_surrogate, json::parse_error&);
        }
    }

@@ -89,22 +68,11 @@ TEST_CASE("wide strings")

    SECTION("invalid std::u16string")
    {
-        if (u16string_is_utf16())
+        if (wstring_is_utf16())
        {
            std::u16string const w = u"\"\xDBFF";
            json _;
            CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
-
-            // a lone low surrogate cannot start a pair
-            CHECK_THROWS_WITH_AS(_ = json::parse(std::u16string{u'"', 0xDC00, u'"'}), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'", json::parse_error&);
-            // a high surrogate followed by a non-low-surrogate unit is invalid
-            CHECK_THROWS_WITH_AS(_ = json::parse(std::u16string{u'"', 0xD800, u'a', u'"'}), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'", json::parse_error&);
-            // a lone low surrogate must not swallow the following unit: pairing
-            // it with any second unit would produce valid UTF-8, so the error
-            // has to report an ill-formed byte at the surrogate's own position
-            CHECK_THROWS_WITH_AS(_ = json::parse(std::u16string{u'"', 0xDC00, u'a', u'"'}), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'", json::parse_error&);
-            // a valid surrogate pair is still decoded (U+1F600)
-            CHECK(json::parse(std::u16string{u'"', 0xD83D, 0xDE00, u'"'}).get<std::string>() == "\xF0\x9F\x98\x80");
        }
    }
Author	SHA1	Message	Date
Niels Lohmann	0e03ecee10	Extend memcpy fast path to sized sentinels (e.g. std::counted_iterator) Extend the memcpy fast path in iterator_input_adapter to sized sentinels of a different type, not just same-type iterator pairs. std::counted_iterator paired with std::default_sentinel_t already satisfies std::contiguous_iterator and std::sized_sentinel_for, so std::ranges::distance (C++20) lets that combination reach the fast path too, instead of silently falling back to the byte-by-byte path. - iterator_is_contiguous now also allows std::sized_sentinel_for<SentinelType, IteratorType> under C++20, gated the same way as the existing std::contiguous_iterator detection. - get_elements_impl's fast path uses std::ranges::distance under C++20 (works for both same-type and sized-sentinel pairs) and falls back to std::distance pre-C++20, where SentinelType is always IteratorType. - Add a C++20-only test exercising json::parse/accept with std::counted_iterator + std::default_sentinel_t. - Document std::default_sentinel_t + std::counted_iterator as a SentinelType example across parse.md, accept.md, sax_parse.md, and the five from_*.md pages, replacing an earlier ambiguously worded bullet. Addresses review feedback: https://github.com/nlohmann/json/pull/5265#discussion_r3564237584 Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-11 16:26:09 +02:00
Niels Lohmann	d23806a327	Fix clang-tidy misc-const-correctness in heterogeneous sentinel test json_str is only read via .data()/.size() and never reassigned, so clang-tidy correctly flags it as const-able. Verified against the exact CI job (silkeh/clang:dev, ci_clang_tidy target) by running clang-tidy directly on this file plus the five binary-format sentinel tests touched by prior commits; all are now clean. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-11 10:06:11 +02:00
Niels Lohmann	fa9741f0ce	Fix clang-tidy hicpp-named-parameter and misc-const-correctness - Drop the unused reversed-order operator!= overload from utils::istreambuf_sentinel (only iterator != sentinel is ever evaluated) and name the remaining friend's sentinel parameter, fixing hicpp-named-parameter/readability-named-parameter. - Mark the istreambuf_iterator first/last helper variable const in the five binary-format sentinel tests, fixing misc-const-correctness. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-11 00:10:23 +02:00
Niels Lohmann	da95d1184e	Fix -Wunneeded-internal-declaration for CustomSentinel in test CustomSentinel lives in an anonymous namespace (internal linkage), and the library's parse loop only ever evaluates the iterator-first direction (it != last), so the reversed-order friend operator!= was never referenced. Clang's -Weverything flags such unused internal declarations as an error. Drop the unused overload; the used direction is enough to satisfy can_compare_ne's either-order detection. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-10 23:25:21 +02:00
Niels Lohmann	146e5e0bc7	Merge iterator+sentinel overloads and fix ambiguity/CI issues Address PR review feedback and CI failures: - Merge the separate same-type and sentinel-type iterator overloads of parse(), accept(), sax_parse(), and the five from_* binary deserializers into a single overload with SentinelType defaulted to IteratorType, as suggested in review. Applied the same simplification to the detail::input_adapter() free functions. - Fix a latent ambiguity: some compilers (e.g. GCC 4.8) unreliably SFINAE the operator!= detection for std::nullptr_t against container/string types, making calls like parse(s, nullptr, ...) ambiguous with the compatible-input overload. can_compare_ne now explicitly excludes std::nullptr_t as a SentinelType. - Use a named enable_if_t template parameter instead of an unnamed function parameter for the SFINAE guard, fixing a clang-tidy hicpp-named-parameter/readability-named-parameter failure. - Update parse.md, accept.md, sax_parse.md, and the five from_*.md pages to document the merged overload instead of separate (2)/(3) overloads, also fixing an over-160-char line that broke the documentation style_check CI job. - Rework the BSON iterator+sentinel test to parse a BSON file already present in the test suite instead of writing/deleting a temp file. Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-10 23:15:17 +02:00
Niels Lohmann	2269656bc6	Add iterator+sentinel tests and docs for binary deserializers This commit extends the C++20 ranges support (iterator+sentinel pairs) to the binary format deserializers from_cbor, from_msgpack, from_ubjson, from_bjdata, and from_bson, matching what was already done for parse(), accept(), and sax_parse(). Changes: - Add istreambuf_sentinel helper to test_utils.hpp for EOF detection in tests - Add 5 new test cases that read binary files directly via std::istreambuf_iterator<char> + sentinel, without pre-buffering - Update documentation for all 5 from_* functions to document overload (3) with SentinelType parameter - All tests pass; verified against existing test suite data - Fix potential buffer over-read warning in heterogeneous iterator test Signed-off-by: Niels Lohmann <mail@nlohmann.me>	2026-07-10 19:50:04 +02:00