refactor: split implementation files and add more inline / constexpr / noexcept qualifiers

.clang-format

@@ -53,3 +53,6 @@ SeparateDefinitionBlocks: Leave
 SkipMacroDefinitionBody: false
 SortIncludes: CaseSensitive
 SpaceAroundPointerQualifiers: Both
+StatementAttributeLikeMacros:
+  - Py_ALWAYS_INLINE
+  - Py_NO_INLINE

.clang-tidy

@@ -17,6 +17,7 @@ Checks: |
   misc-*,
   modernize-*,
   -modernize-use-trailing-return-type,
+  -modernize-use-transparent-functors,
   performance-*,
   readability-*,
   -readability-redundant-inline-specifier,

.github/workflows/build.yml

@@ -39,8 +39,8 @@ concurrency:
 jobs:
   build-sdist:
     name: Build sdist
-    runs-on: ubuntu-latest
     if: github.repository == 'metaopt/optree' && (github.event_name != 'push' || startsWith(github.ref, 'refs/tags/'))
+    runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
       - name: Checkout
@@ -80,15 +80,15 @@ jobs:
           if-no-files-found: error
 
   build-wheels:
-    name: Build wheels for Python ${{ matrix.python-version }} on ${{ matrix.os }} (${{ matrix.archs }})
-    runs-on: ${{ matrix.os }}
-    needs: [build-sdist]
+    name: Build wheels for Python ${{ matrix.python-version }} on ${{ matrix.runner }} (${{ matrix.archs }})
     if: github.repository == 'metaopt/optree' && (github.event_name != 'push' || startsWith(github.ref, 'refs/tags/'))
+    runs-on: ${{ matrix.runner }}
+    needs: [build-sdist]
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        runner: [ubuntu-latest, windows-latest, macos-latest]
         python-version:
-          ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "pypy-3.9", "pypy-3.10"]
+          ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.13t", "pypy-3.9", "pypy-3.10"]
         archs: [
             # Generic
             "auto",
@@ -100,62 +100,72 @@ jobs:
             "ARM64",
           ]
         include:
-          - os: macos-13
+          - runner: macos-13
             python-version: "3.7"
             archs: "auto"
         exclude:
-          - os: ubuntu-latest
-            archs: "ARM64"
-          - os: windows-latest
-            archs: "aarch64"
-          - os: windows-latest
-            archs: "ppc64le"
-          - os: windows-latest
-            archs: "s390x"
-          - os: macos-latest
-            archs: "aarch64"
-          - os: macos-latest
-            archs: "ppc64le"
-          - os: macos-latest
-            archs: "s390x"
-          - os: macos-latest
-            archs: "ARM64"
-          - os: ubuntu-latest
+          - runner: ubuntu-latest
             python-version: "pypy-3.9"
             archs: "ppc64le"
-          - os: ubuntu-latest
+          - runner: ubuntu-latest
             python-version: "pypy-3.10"
             archs: "ppc64le"
-          - os: ubuntu-latest
+          - runner: ubuntu-latest
             python-version: "pypy-3.9"
             archs: "s390x"
-          - os: ubuntu-latest
+          - runner: ubuntu-latest
             python-version: "pypy-3.10"
             archs: "s390x"
-          - os: windows-latest
+          - runner: windows-latest
             python-version: "3.7"
             archs: "ARM64"
-          - os: windows-latest
+          - runner: windows-latest
             python-version: "3.8"
             archs: "ARM64"
-          - os: windows-latest
+          - runner: windows-latest
             python-version: "pypy-3.9"
             archs: "ARM64"
-          - os: windows-latest
+          - runner: windows-latest
             python-version: "pypy-3.10"
             archs: "ARM64"
-          - os: macos-latest
-            python-version: "3.7"
+          - runner: macos-latest
+            python-version: "3.7"  # Python 3.7 does not support macOS ARM64
+
+          # Exclude archs of other platforms
+          - runner: ubuntu-latest
+            archs: "ARM64"
+          - runner: windows-latest
+            archs: "aarch64"
+          - runner: windows-latest
+            archs: "ppc64le"
+          - runner: windows-latest
+            archs: "s390x"
+          - runner: macos-latest
+            archs: "aarch64"
+          - runner: macos-latest
+            archs: "ppc64le"
+          - runner: macos-latest
+            archs: "s390x"
+          - runner: macos-latest
+            archs: "ARM64"
       fail-fast: false
     timeout-minutes: 180
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Determine Python version
+        shell: bash
+        run: |
+          PYTHON_VERSION="${{ matrix.python-version }}"
+          PYTHON_VERSION="${PYTHON_VERSION%t}"
+          echo "Using Python version: ${PYTHON_VERSION}"
+          echo "PYTHON_VERSION=${PYTHON_VERSION}" >> "${GITHUB_ENV}"
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: ${{ env.PYTHON_VERSION }}
           update-environment: true
           allow-prereleases: true
 
@@ -173,7 +183,22 @@ jobs:
         run: python setup.py --version
 
       - name: Set CIBW_BUILD
-        run: python .github/workflows/set_cibw_build.py
+        shell: bash
+        run: |
+          PYTHON_TAG="$(
+            python -c \
+              "import sys; print(
+                '{0.name[0]}p{1.major}{1.minor}'.format(
+                  sys.implementation,
+                  sys.version_info,
+                ).lower(),
+              )"
+          )"
+          if [[ "${{ matrix.python-version }}" == *"t" ]]; then
+            PYTHON_TAG="${PYTHON_TAG}t"
+          fi
+          echo "PYTHON_TAG=${PYTHON_TAG}" | tee -a "${GITHUB_ENV}"
+          echo "CIBW_BUILD=${PYTHON_TAG}-*" | tee -a "${GITHUB_ENV}"
 
       - name: Set up QEMU
         if: runner.os == 'Linux'
@@ -194,15 +219,15 @@ jobs:
 
       - uses: actions/upload-artifact@v4
         with:
-          name: wheels-${{ matrix.python-version }}-${{ matrix.os }}-${{ matrix.archs }}
+          name: wheels-${{ env.PYTHON_TAG }}-${{ runner.os }}-${{ matrix.archs }}
           path: wheelhouse/*.whl
           if-no-files-found: error
 
   list-artifacts:
     name: List artifacts
+    if: github.repository == 'metaopt/optree' && (github.event_name != 'push' || startsWith(github.ref, 'refs/tags/'))
     runs-on: ubuntu-latest
     needs: [build-sdist, build-wheels]
-    if: github.repository == 'metaopt/optree' && (github.event_name != 'push' || startsWith(github.ref, 'refs/tags/'))
     timeout-minutes: 15
     steps:
       - name: Download built sdist
@@ -243,8 +268,8 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Set up Python
-        uses: actions/setup-python@v5
         if: startsWith(github.ref, 'refs/tags/')
+        uses: actions/setup-python@v5
         with:
           python-version: "3.7 - 3.13"
           update-environment: true

.github/workflows/lint.yml

@@ -74,7 +74,7 @@ jobs:
 
       - name: clang-tidy
         run: |
-          make clang-tidy
+          make clang-tidy CMAKE_CXX_STANDARD=17
 
       - name: addlicense
         run: |

.github/workflows/tests-with-pydebug.yml

@@ -31,11 +31,11 @@ env:
 
 jobs:
   test:
-    name: Test for Python ${{ matrix.python-version }}${{ matrix.python-abiflags }} on ${{ matrix.os }}
-    runs-on: ${{ matrix.os }}
+    name: Test for Python ${{ matrix.python-version }}${{ matrix.python-abiflags }} on ${{ matrix.runner }}
+    runs-on: ${{ matrix.runner }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        runner: [ubuntu-latest, windows-latest, macos-latest]
         python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
         python-abiflags: ["d", "td"]
         exclude:
@@ -51,7 +51,7 @@ jobs:
             python-abiflags: "td"
           - python-version: "3.12"
             python-abiflags: "td"
-          - os: windows-latest  # pyenv-win does not support Python 3.13t yet
+          - runner: windows-latest  # pyenv-win does not support Python 3.13t yet
             python-version: "3.13"
             python-abiflags: "td"
       fail-fast: false

.github/workflows/tests.yml

@@ -32,18 +32,18 @@ env:
 
 jobs:
   test:
-    name: Test for Python ${{ matrix.python-version }} on ${{ matrix.os }}
-    runs-on: ${{ matrix.os }}
+    name: Test for Python ${{ matrix.python-version }} on ${{ matrix.runner }}
+    runs-on: ${{ matrix.runner }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        runner: [ubuntu-latest, windows-latest, macos-latest]
         python-version:
           ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "pypy-3.9", "pypy-3.10"]
         include:
-          - os: macos-13
+          - runner: macos-13
             python-version: "3.7"
         exclude:
-          - os: macos-latest
+          - runner: macos-latest
             python-version: "3.7"  # Python 3.7 does not support macOS ARM64
       fail-fast: false
     timeout-minutes: 90
@@ -74,6 +74,13 @@ jobs:
             python -m pip install -r tests/requirements.txt
           fi
 
+      - name: Test installable with C++17
+        if: runner.os != 'Windows'
+        run: |
+          OPTREE_CXX_WERROR=OFF CMAKE_CXX_STANDARD=17 python -m pip install -vvv --editable .
+          python -X dev -W 'always' -W 'error' -c 'import optree'
+          python -m pip uninstall -y optree
+
       - name: Install OpTree
         run: |
           python -m pip install -vvv --editable '.[test]'
@@ -83,8 +90,8 @@ jobs:
           make test PYTESTOPTS="--exitfirst"
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v4
         if: runner.os == 'Linux'
+        uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./tests/coverage.xml

.pre-commit-config.yaml

@@ -26,7 +26,7 @@ repos:
       - id: debug-statements
       - id: double-quote-string-fixer
   - repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v19.1.0
+    rev: v19.1.1
     hooks:
       - id: clang-format
   - repo: https://github.com/astral-sh/ruff-pre-commit

CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Split implementation files and add more `inline` / `constexpr` / `noexcept` qualifiers by [@XuehaiPan](https://github.com/XuehaiPan) in [#159](https://github.com/metaopt/optree/pull/159).
 - Use `cmake`'s `FindPython` module by [@XuehaiPan](https://github.com/XuehaiPan) in [#151](https://github.com/metaopt/optree/pull/151).
 
 ### Fixed

CMakeLists.txt

@@ -32,8 +32,17 @@ if(NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE Release)
 endif()
 
-set(CMAKE_CXX_STANDARD 20)  # for likely/unlikely attributes
+if(NOT DEFINED CMAKE_CXX_STANDARD AND NOT "$ENV{CMAKE_CXX_STANDARD}" STREQUAL "")
+    set(CMAKE_CXX_STANDARD "$ENV{CMAKE_CXX_STANDARD}")
+endif()
+if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 20)  # for likely/unlikely attributes
+endif()
+if (CMAKE_CXX_STANDARD VERSION_LESS 17)
+    message(FATAL_ERROR "C++17 or higher is required")
+endif()
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
+message(STATUS "Use C++ standard: C++${CMAKE_CXX_STANDARD}")
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)  # -fPIC
 set(CMAKE_CXX_VISIBILITY_PRESET hidden)  # -fvisibility=hidden
@@ -51,6 +60,7 @@ endif()
 if(MSVC)
     string(
         APPEND CMAKE_CXX_FLAGS
+        " /EHsc /bigobj"
         " /Zc:preprocessor"
         " /experimental:external /external:anglebrackets /external:W0"
         " /Wall /Wv:19.40"  # Visual Studio 2022 version 17.10
@@ -59,6 +69,7 @@ if(MSVC)
         " /wd4514"  # unreferenced inline function has been removed
         " /wd4710"  # function not inlined
         " /wd4711"  # function selected for inline expansion
+        " /wd4714"  # function marked as forceinline not inlined
         " /wd4820"  # bytes padding added after construct 'member_name'
         " /wd4868"  # compiler may not enforce left-to-right evaluation order in braced initializer list
         " /wd5045"  # compiler will insert Spectre mitigation for memory load if /Qspectre switch specified
@@ -88,7 +99,7 @@ if(OPTREE_CXX_WERROR)
 endif()
 
 string(LENGTH "${CMAKE_SOURCE_DIR}/" SOURCE_PATH_PREFIX_SIZE)
-add_definitions("-DSOURCE_PATH_PREFIX_SIZE=(${SOURCE_PATH_PREFIX_SIZE})")
+add_definitions("-DSOURCE_PATH_PREFIX_SIZE=${SOURCE_PATH_PREFIX_SIZE}")
 
 function(system)
     set(options STRIP)