Add migration guide

.clang-tidy

@@ -6,6 +6,8 @@ Checks: '*,
          -bugprone-easily-swappable-parameters,
          -cert-err58-cpp,
          -concurrency-mt-unsafe,
+         -cppcoreguidelines-avoid-const-or-ref-data-members,
+         -cppcoreguidelines-avoid-do-while,
          -cppcoreguidelines-avoid-goto,
          -cppcoreguidelines-avoid-magic-numbers,
          -cppcoreguidelines-avoid-non-const-global-variables,
@@ -33,6 +35,7 @@ Checks: '*,
          -llvm-header-guard,
          -llvm-include-order,
          -llvmlibc-*,
+         -misc-confusable-identifiers,
          -misc-no-recursion,
          -misc-non-private-member-variables-in-classes,
          -modernize-concat-nested-namespaces,

.github/CONTRIBUTING.md

@@ -55,7 +55,7 @@ To make changes, you need to edit the following files:
 ## Please don't
 
 - The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
-- Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for these kind of bugs). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
+- Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for this kind of bug). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
 - Please refrain from proposing changes that would **break [JSON](https://json.org) conformance**. If you propose a conformant extension of JSON to be supported by the library, please motivate this extension.
   - We shall not extend the library to **support comments**. There is quite some [controversy](https://www.reddit.com/r/programming/comments/4v6chu/why_json_doesnt_support_comments_douglas_crockford/) around this topic, and there were quite some [issues](https://github.com/nlohmann/json/issues/376) on this. We believe that JSON is fine without comments.
   - We do not preserve the **insertion order of object elements**. The [JSON standard](https://tools.ietf.org/html/rfc8259.html) defines objects as "an unordered collection of zero or more name/value pairs". To this end, this library does not preserve insertion order of name/value pairs. (In fact, keys will be traversed in alphabetical order as `std::map` with `std::less` is used by default.) Note this behavior conforms to the standard, and we shall not change it to any other order. If you do want to preserve the insertion order, you can specialize the object type with containers like [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) or [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map).

.github/PULL_REQUEST_TEMPLATE.md

@@ -14,6 +14,6 @@ Read the [Contribution Guidelines](https://github.com/nlohmann/json/blob/develop
 ## Please don't
 
 - The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
-- Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for these kind of bugs). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
+- Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for this kind of bug). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
 - Please refrain from proposing changes that would **break [JSON](https://json.org) conformance**. If you propose a conformant extension of JSON to be supported by the library, please motivate this extension.
 - Please do not open pull requests that address **multiple issues**.

.github/workflows/check_amalgamation.yml

@@ -0,0 +1,92 @@
+name: "Check amalgamation"
+
+on:
+  pull_request_target:
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    env:
+      MAIN_DIR: ${{ github.workspace }}/main
+      INCLUDE_DIR: ${{ github.workspace }}/main/single_include/nlohmann
+      TOOL_DIR: ${{ github.workspace }}/tools/tools/amalgamate
+      ASTYLE_FLAGS: >
+        --style=allman --indent=spaces=4 --indent-modifiers --indent-switches --indent-preproc-block
+        --indent-preproc-define --indent-col1-comments --pad-oper --pad-header --align-pointer=type
+        --align-reference=type --add-brackets --convert-tabs --close-templates --lineend=linux --preserve-date
+        --formatted
+
+    steps:
+      - name: Checkout pull request
+        uses: actions/checkout@v3
+        with:
+          path: main
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Checkout tools
+        uses: actions/checkout@v3
+        with:
+          path: tools
+          ref: develop
+
+      - name: Install astyle
+        run: |
+          sudo apt-get update
+          sudo apt-get install astyle
+
+      - name: Check amalgamation
+        run: |
+          cd $MAIN_DIR
+
+          rm -fr $INCLUDE_DIR/json.hpp~ $INCLUDE_DIR/json_fwd.hpp~
+          cp $INCLUDE_DIR/json.hpp $INCLUDE_DIR/json.hpp~
+          cp $INCLUDE_DIR/json_fwd.hpp $INCLUDE_DIR/json_fwd.hpp~
+
+          python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json.json -s .
+          python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json_fwd.json -s .
+          echo "Format (1)"
+          astyle $ASTYLE_FLAGS --suffix=none --quiet $INCLUDE_DIR/json.hpp $INCLUDE_DIR/json_fwd.hpp
+
+          diff $INCLUDE_DIR/json.hpp~ $INCLUDE_DIR/json.hpp
+          diff $INCLUDE_DIR/json_fwd.hpp~ $INCLUDE_DIR/json_fwd.hpp
+
+          astyle $ASTYLE_FLAGS $(find docs/examples include tests -type f \( -name '*.hpp' -o -name '*.cpp' -o -name '*.cu' \) -not -path 'tests/thirdparty/*' -not -path 'tests/abi/include/nlohmann/*' | sort)
+          echo Check
+          find $MAIN_DIR -name '*.orig' -exec false {} \+
+
+      - name: Comment on pull request
+        if: failure()
+        uses: actions/github-script@v6
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          script: |
+            const author = context.payload.pull_request.user.login
+            const opts = github.rest.issues.listForRepo.endpoint.merge({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              creator: author,
+              state: 'all'
+            })
+
+            let first = true
+            const issues = await github.paginate(opts)
+            for (const issue of issues) {
+              if (issue.number === context.issue.number) {
+                continue
+              }
+
+              if (issue.pull_request) {
+                first = false
+                break
+              }
+            }
+
+            await github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: '## 🔴 Amalgamation check failed! 🔴\nThe source code has not been amalgamated.'
+                    + (first ? ' @' + author + ' Please read and follow the [Contribution Guidelines]'
+                               + '(https://github.com/nlohmann/json/blob/develop/.github/CONTRIBUTING.md#files-to-change).'
+                             : '')
+              })

.github/workflows/cifuzz.yml

@@ -0,0 +1,26 @@
+name: CIFuzz
+on: [pull_request]
+jobs:
+  Fuzzing:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Build Fuzzers
+      id: build
+      uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
+      with:
+        oss-fuzz-project-name: 'json'
+        dry-run: false
+        language: c++
+    - name: Run Fuzzers
+      uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
+      with:
+        oss-fuzz-project-name: 'json'
+        fuzz-seconds: 300
+        dry-run: false
+        language: c++
+    - name: Upload Crash
+      uses: actions/upload-artifact@v3
+      if: failure() && steps.build.outcome == 'success'
+      with:
+        name: artifacts
+        path: ./out/artifacts

.github/workflows/macos.yml

@@ -35,7 +35,7 @@ jobs:
     runs-on: macos-12
     strategy:
       matrix:
-        xcode: ['13.1', '13.2.1', '13.3.1', '13.4.1']
+        xcode: ['13.1', '13.2.1', '13.3.1', '13.4.1', '14.0', '14.0.1', '14.1']
     env:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
 
@@ -53,8 +53,6 @@ jobs:
     strategy:
       matrix:
         standard: [11, 14, 17, 20]
-    env:
-      DEVELOPER_DIR: /Applications/Xcode_12.4.app/Contents/Developer
 
     steps:
       - uses: actions/checkout@v3

.github/workflows/ubuntu.yml

@@ -16,9 +16,13 @@ concurrency:
 jobs:
   ci_test_clang:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.4.0
+    container: silkeh/clang:dev
     steps:
+      - name: Install git and unzip
+        run: apt-get update ; apt-get install -y git unzip
       - uses: actions/checkout@v3
+      - name: Get latest CMake and ninja
+        uses: lukka/get-cmake@latest
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -39,32 +43,57 @@ jobs:
     container: ghcr.io/nlohmann/json-ci:v2.4.0
     strategy:
       matrix:
-        target: [ci_clang_tidy, ci_cppcheck, ci_test_valgrind, ci_test_clang_sanitizer, ci_test_amalgamation, ci_clang_analyze, ci_cpplint, ci_cmake_flags, ci_single_binaries, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_infer]
+        target: [ci_cppcheck, ci_test_valgrind, ci_test_amalgamation, ci_test_single_header, ci_single_binaries, ci_infer]
     steps:
       - uses: actions/checkout@v3
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
         run: cmake --build build --target ${{ matrix.target }}
 
-  ci_test_single_header:
+  ci_static_analysis_ubuntu:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.4.0
+    strategy:
+      matrix:
+        target: [ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata]
     steps:
       - uses: actions/checkout@v3
+      - name: Get latest CMake and ninja
+        uses: lukka/get-cmake@latest
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
-        run: cmake --build build --target ci_test_single_header
+        run: cmake --build build --target ${{ matrix.target }}
+
+  ci_static_analysis_clang:
+    runs-on: ubuntu-latest
+    container: silkeh/clang:dev
+    strategy:
+      matrix:
+        target: [ci_clang_tidy, ci_test_clang_sanitizer, ci_clang_analyze]
+    steps:
+      - name: Install git, clang-tools, and unzip
+        run: apt-get update ; apt-get install -y git clang-tools unzip
+      - uses: actions/checkout@v3
+      - name: Get latest CMake and ninja
+        uses: lukka/get-cmake@latest
+      - name: Run CMake
+        run: cmake -S . -B build -DJSON_CI=On
+      - name: Build
+        run: cmake --build build --target ${{ matrix.target }}
 
   ci_cmake_options:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.4.0
+    container: ubuntu:focal
     strategy:
       matrix:
-        target: [ci_test_diagnostics, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls]
+        target: [ci_cmake_flags, ci_test_diagnostics, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls]
     steps:
+      - name: Install build-essential
+        run: apt-get update ; apt-get install -y build-essential unzip wget git
       - uses: actions/checkout@v3
+      - name: Get latest CMake and ninja
+        uses: lukka/get-cmake@latest
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -90,12 +119,44 @@ jobs:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           path-to-lcov: ${{ github.workspace }}/build/json.info.filtered.noexcept
 
+  ci_test_compilers_gcc:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        compiler: ['4', '5', '6', '7', '8', '9', '10', '11', '12', 'latest']
+    container: gcc:${{ matrix.compiler }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Get latest CMake and ninja
+        uses: lukka/get-cmake@latest
+      - name: Run CMake
+        run: cmake -S . -B build -DJSON_CI=On
+      - name: Build
+        run: cmake --build build --target ci_test_compiler_default
+
+  ci_test_compilers_clang:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        compiler: ['3.5', '3.6', '3.7', '3.8', '3.9', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15-bullseye', 'latest']
+    container: silkeh/clang:${{ matrix.compiler }}
+    steps:
+      - name: Install unzip and git
+        run: apt-get update ; apt-get install -y unzip git
+      - uses: actions/checkout@v3
+      - name: Get latest CMake and ninja
+        uses: lukka/get-cmake@latest
+      - name: Run CMake
+        run: cmake -S . -B build -DJSON_CI=On
+      - name: Build
+        run: cmake --build build --target ci_test_compiler_default
+
   ci_test_compilers:
     runs-on: ubuntu-latest
     container: ghcr.io/nlohmann/json-ci:v2.4.0
     strategy:
       matrix:
-        compiler: [g++-4.8, g++-4.9, g++-5, g++-6, g++-7, g++-8, g++-9, g++-10, g++-11, clang++-3.5, clang++-3.6, clang++-3.7, clang++-3.8, clang++-3.9, clang++-4.0, clang++-5.0, clang++-6.0, clang++-7, clang++-8, clang++-9, clang++-10, clang++-11, clang++-12, clang++-13, clang++-14]
+        compiler: [g++-4.8]
     steps:
       - uses: actions/checkout@v3
       - name: Run CMake

.reuse/dep5

@@ -27,10 +27,6 @@ Files: tools/amalgamate/*
 Copyright: 2012 Erik Edlund <erik.edlund@32767.se>
 License: BSD-3-Clause
 
-Files: tools/cpplint/*
-Copyright: 2009 Google Inc. All rights reserved.
-License: BSD-3-Clause
-
 Files: tools/gdb_pretty_printer
 Copyright: 2020 Hannes Domani <https://github.com/ssbssa>
 License: MIT

BUILD.bazel

@@ -0,0 +1,53 @@
+cc_library(
+    name = "json",
+    hdrs = [
+        "include/nlohmann/adl_serializer.hpp",
+        "include/nlohmann/byte_container_with_subtype.hpp",
+        "include/nlohmann/detail/abi_macros.hpp",
+        "include/nlohmann/detail/conversions/from_json.hpp",
+        "include/nlohmann/detail/conversions/to_chars.hpp",
+        "include/nlohmann/detail/conversions/to_json.hpp",
+        "include/nlohmann/detail/exceptions.hpp",
+        "include/nlohmann/detail/hash.hpp",
+        "include/nlohmann/detail/input/binary_reader.hpp",
+        "include/nlohmann/detail/input/input_adapters.hpp",
+        "include/nlohmann/detail/input/json_sax.hpp",
+        "include/nlohmann/detail/input/lexer.hpp",
+        "include/nlohmann/detail/input/parser.hpp",
+        "include/nlohmann/detail/input/position_t.hpp",
+        "include/nlohmann/detail/iterators/internal_iterator.hpp",
+        "include/nlohmann/detail/iterators/iter_impl.hpp",
+        "include/nlohmann/detail/iterators/iteration_proxy.hpp",
+        "include/nlohmann/detail/iterators/iterator_traits.hpp",
+        "include/nlohmann/detail/iterators/json_reverse_iterator.hpp",
+        "include/nlohmann/detail/iterators/primitive_iterator.hpp",
+        "include/nlohmann/detail/json_custom_base_class.hpp",
+        "include/nlohmann/detail/json_pointer.hpp",
+        "include/nlohmann/detail/json_ref.hpp",
+        "include/nlohmann/detail/macro_scope.hpp",
+        "include/nlohmann/detail/macro_unscope.hpp",
+        "include/nlohmann/detail/meta/call_std/begin.hpp",
+        "include/nlohmann/detail/meta/call_std/end.hpp",
+        "include/nlohmann/detail/meta/cpp_future.hpp",
+        "include/nlohmann/detail/meta/detected.hpp",
+        "include/nlohmann/detail/meta/identity_tag.hpp",
+        "include/nlohmann/detail/meta/is_sax.hpp",
+        "include/nlohmann/detail/meta/std_fs.hpp",
+        "include/nlohmann/detail/meta/type_traits.hpp",
+        "include/nlohmann/detail/meta/void_t.hpp",
+        "include/nlohmann/detail/output/binary_writer.hpp",
+        "include/nlohmann/detail/output/output_adapters.hpp",
+        "include/nlohmann/detail/output/serializer.hpp",
+        "include/nlohmann/detail/string_concat.hpp",
+        "include/nlohmann/detail/string_escape.hpp",
+        "include/nlohmann/detail/value_t.hpp",
+        "include/nlohmann/json.hpp",
+        "include/nlohmann/json_fwd.hpp",
+        "include/nlohmann/ordered_map.hpp",
+        "include/nlohmann/thirdparty/hedley/hedley.hpp",
+        "include/nlohmann/thirdparty/hedley/hedley_undef.hpp",
+    ],
+    includes = ["include"],
+    visibility = ["//visibility:public"],
+    alwayslink = True,
+)

CMakeLists.txt

@@ -43,7 +43,7 @@ option(JSON_Diagnostics                    "Use extended diagnostic messages." O
 option(JSON_GlobalUDLs                     "Place use-defined string literals in the global namespace." ON)
 option(JSON_ImplicitConversions            "Enable implicit conversions." ON)
 option(JSON_DisableEnumSerialization       "Disable default integer enum serialization." OFF)
-option(JSON_LegacyDiscardedValueComparison "Enable legacy discarded value comparison." OFF)           
+option(JSON_LegacyDiscardedValueComparison "Enable legacy discarded value comparison." OFF)
 option(JSON_Install                        "Install CMake targets during install step." ${MAIN_PROJECT})
 option(JSON_MultipleHeaders                "Use non-amalgamated version of the library." ON)
 option(JSON_SystemInclude                  "Include as system headers (skip for clang-tidy)." OFF)