header only build option

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        build: [1, 2, 3, 4]
+        build: [1, 2, 3, 4, 5, 6]
         include:
           # -------------------------------------------------------------------
           # CLANG, Release
@@ -75,6 +75,36 @@ jobs:
             compiler-desc: gcc
             os: ubuntu-latest
 
+
+          # -------------------------------------------------------------------
+          # CLANG, Release header only
+          # -------------------------------------------------------------------
+          - build: 5
+            build-type: Release
+            build-shared: 'ON'
+            header-only: 'ON'
+            cxx-standard: 17
+            cxx-compiler: clang++
+            cxx-flags: ''
+            cc-compiler: clang
+            compiler-desc: clang
+            os: ubuntu-latest
+
+          # -------------------------------------------------------------------
+          # gcc, Release header only
+          # -------------------------------------------------------------------
+          - build: 6
+            build-type: Release
+            build-shared: 'ON'
+            header-only: 'ON'
+            cxx-standard: 17
+            cxx-compiler: g++
+            cxx-flags: ''
+            cc-compiler: gcc
+            compiler-desc: gcc
+            os: ubuntu-latest
+
+
     env:
       CXX: ${{ matrix.cxx-compiler }}
       CC: ${{ matrix.cc-compiler }}
@@ -88,17 +118,17 @@ jobs:
       - name: Configure
         run: |
           cmake .. \
-                -DCMAKE_INSTALL_PREFIX=../_install \
+                -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install \
                 -DCMAKE_BUILD_TYPE=${{ matrix.build-type }} \
                 -DCMAKE_CXX_STANDARD=${{ matrix.cxx-standard }} \
                 -DCMAKE_CXX_FLAGS=${{ matrix.cxx-flags }} \
                 -DCMAKE_VERBOSE_MAKEFILE:BOOL='OFF' \
                 -DBUILD_SHARED_LIBS=${{ matrix.build-shared }} \
+                -DPYSTRING_HEADER_ONLY=${{ matrix.header-only }}
         working-directory: _build
       - name: Build
         run: |
           cmake --build . \
-                --target install \
                 --config ${{ matrix.build-type }}
         working-directory: _build
       - name: Test
@@ -115,7 +145,7 @@ jobs:
     runs-on: macos-latest
     strategy:
       matrix:
-        build: [1, 2]
+        build: [1, 2, 3]
         include:
 
           # Release
@@ -135,6 +165,16 @@ jobs:
             cxx-flags: ''
             os: macos-latest
 
+
+          # Release header only
+          - build: 3
+            build-type: Release
+            build-shared: 'ON'
+            header-only: 'ON'
+            cxx-standard: 17
+            cxx-flags: ''
+            os: macos-latest
+
     steps:
       - name: Checkout
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
@@ -146,17 +186,17 @@ jobs:
       - name: Configure
         run: |
           cmake ../. \
-                -DCMAKE_INSTALL_PREFIX=../_install \
+                -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install \
                 -DCMAKE_BUILD_TYPE=${{ matrix.build-type }} \
                 -DCMAKE_CXX_STANDARD=${{ matrix.cxx-standard }} \
                 -DCMAKE_CXX_FLAGS=${{ matrix.cxx-flags }} \
                 -DCMAKE_VERBOSE_MAKEFILE:BOOL='OFF' \
-                -DBUILD_SHARED_LIBS=${{ matrix.build-shared }}
+                -DBUILD_SHARED_LIBS=${{ matrix.build-shared }} \
+                -DPYSTRING_HEADER_ONLY=${{ matrix.header-only }}
         working-directory: _build
       - name: Build
         run: |
           cmake --build . \
-                --target install \
                 --config ${{ matrix.build-type }} \
         working-directory: _build
       - name: Test
@@ -192,6 +232,15 @@ jobs:
             cxx-flags: ''
             os: windows-latest
 
+          # Release header only
+          - build: 3
+            build-type: Release
+            build-shared: 'ON'
+            header-only: 'ON'
+            cxx-standard: 17
+            cxx-flags: ''
+            os: windows-latest
+
 
     steps:
       - name: Checkout
@@ -205,19 +254,19 @@ jobs:
       # the windows build needs the -DCMAKE_WINDOWS_EXPORT_ALL_SYMBOLS to work
         run: |
           cmake ../. \
-                -DCMAKE_INSTALL_PREFIX=../_install \
+                -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install \
                 -DCMAKE_WINDOWS_EXPORT_ALL_SYMBOLS='ON'\
                 -DCMAKE_BUILD_TYPE=${{ matrix.build-type }} \
                 -DCMAKE_CXX_STANDARD=${{ matrix.cxx-standard }} \
                 -DCMAKE_CXX_FLAGS=${{ matrix.cxx-flags }} \
                 -DCMAKE_VERBOSE_MAKEFILE:BOOL='OFF' \
-                -DBUILD_SHARED_LIBS=${{ matrix.build-shared }}
+                -DBUILD_SHARED_LIBS=${{ matrix.build-shared }} \
+                -DPYSTRING_HEADER_ONLY=${{ matrix.header-only }}
         shell: bash
         working-directory: _build
       - name: Build
         run: |
           cmake --build . \
-                --target install \
                 --config ${{ matrix.build-type }}
         shell: bash
         working-directory: _build

.github/workflows/meson.yml

@@ -7,13 +7,16 @@ on:
 jobs:
   meson-build-and-tests:
     runs-on: ${{ matrix.platform }}
-    name: ${{ matrix.platform }}, ${{ matrix.mode.name }} ${{ matrix.flavor }}
+    name: ${{ matrix.platform }}, ${{ matrix.mode.name }} ${{ matrix.flavor }} ${{ matrix.library_mode }}
     strategy:
       fail-fast: false
       matrix:
         flavor:
           - debug
           - release
+        library_mode:
+          - compiled
+          - header-only
         mode:
           - name: default
             extra_envs: {}
@@ -61,6 +64,29 @@ jobs:
           - macos-latest
 
         exclude:
+          # Only test header-only with a subset of configurations to reduce CI time
+          # Test header-only only with default compiler in release mode
+          - library_mode: header-only
+            flavor: debug
+          - library_mode: header-only
+            mode:
+              name: gcc
+          - library_mode: header-only
+            mode:
+              name: clang
+          - library_mode: header-only
+            mode:
+              name: sanitize
+          - library_mode: header-only
+            mode:
+              name: sanitize+asanonly
+          - library_mode: header-only
+            mode:
+              name: clang+sanitize
+          - library_mode: header-only
+            mode:
+              name: clang-cl+sanitize
+
           # clang-cl only makes sense on windows.
           - platform: ubuntu-22.04
             mode:
@@ -125,21 +151,21 @@ jobs:
         if: ${{ matrix.platform == 'windows-2022' }}
         env: ${{ matrix.mode.extra_envs }}
         run: |
-          meson setup build-${{ matrix.flavor }} --buildtype=${{ matrix.flavor }} -Ddefault_library=static ${{ matrix.mode.args }} --vsenv
+          meson setup build-${{ matrix.flavor }}-${{ matrix.library_mode }} --buildtype=${{ matrix.flavor }} -Ddefault_library=static -Dheader_only=${{ matrix.library_mode == 'header-only' && 'true' || 'false' }} ${{ matrix.mode.args }} --vsenv
       - name: Configuring
         if: ${{ matrix.platform != 'windows-2022' }}
         env: ${{ matrix.mode.extra_envs }}
         run: |
-          meson setup build-${{ matrix.flavor }} --buildtype=${{ matrix.flavor }} ${{ matrix.mode.args }}
+          meson setup build-${{ matrix.flavor }}-${{ matrix.library_mode }} --buildtype=${{ matrix.flavor }} -Dheader_only=${{ matrix.library_mode == 'header-only' && 'true' || 'false' }} ${{ matrix.mode.args }}
       - name: Building
         run: |
-          meson compile -C build-${{ matrix.flavor }}
+          meson compile -C build-${{ matrix.flavor }}-${{ matrix.library_mode }}
       - name: Running tests
         env: ${{ matrix.mode.extra_envs }}
         run: |
-          meson test -C build-${{ matrix.flavor }} --timeout-multiplier 0
+          meson test -C build-${{ matrix.flavor }}-${{ matrix.library_mode }} --timeout-multiplier 0
       - uses: actions/upload-artifact@v4
         if: failure()
         with:
-          name: ${{ matrix.platform }}-${{ matrix.mode.name }}-${{ matrix.flavor }}-logs
-          path: build-${{ matrix.flavor }}/meson-logs
+          name: ${{ matrix.platform }}-${{ matrix.mode.name }}-${{ matrix.flavor }}-${{ matrix.library_mode }}-logs
+          path: build-${{ matrix.flavor }}-${{ matrix.library_mode }}/meson-logs

CMakeLists.txt

@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.10)
 project(pystring LANGUAGES CXX VERSION 1.1.4)
 
 option (BUILD_SHARED_LIBS "Build shared libraries (set to OFF to build static libs)" ON)
+option(PYSTRING_HEADER_ONLY "Build as header-only library" OFF)
 
 # If the user hasn't configured cmake with an explicit
 # -DCMAKE_INSTALL_PREFIX=..., then set it to safely install into ./dist, to
@@ -13,14 +14,48 @@ if (CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT
 endif()
 message (STATUS "Installation path will be ${CMAKE_INSTALL_PREFIX}")
 
-add_library(pystring
-    pystring.cpp
-    pystring.h
-)
-set_target_properties(pystring PROPERTIES
-    VERSION ${PROJECT_VERSION}
-    SOVERSION ${PROJECT_VERSION_MAJOR}
-)
+if(PYSTRING_HEADER_ONLY)
+    message(STATUS "Building pystring as header-only library")
+    add_library(pystring INTERFACE)
+
+    target_compile_definitions(pystring INTERFACE PYSTRING_HEADER_ONLY)
+
+    target_include_directories(pystring INTERFACE
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+    )
+
+    # Install both headers for header-only mode
+    install(FILES pystring.h pystring_impl.h
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}
+    )
+else()
+    message(STATUS "Building pystring as compiled library")
+
+    add_library(pystring
+        pystring.cpp
+        pystring.h
+    )
+
+    set_target_properties(pystring PROPERTIES
+        VERSION ${PROJECT_VERSION}
+        SOVERSION ${PROJECT_VERSION_MAJOR}
+    )
+
+    install(TARGETS pystring
+            LIBRARY DESTINATION lib
+            RUNTIME DESTINATION bin
+            ARCHIVE DESTINATION lib
+    )
+
+    install (FILES pystring.h
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}
+        COMPONENT developer
+    )
+
+endif()
+
+# Test executable
 
 add_executable (pystring_test test.cpp)
 TARGET_LINK_LIBRARIES (pystring_test pystring)
@@ -29,12 +64,3 @@ enable_testing()
 add_test(NAME PyStringTest COMMAND pystring_test)
 
 include(GNUInstallDirs)
-
-install(TARGETS pystring
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-)
-install (FILES pystring.h
-    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}
-    COMPONENT developer
-)
-

meson.build

@@ -8,25 +8,58 @@ project(
     default_options: ['cpp_std=c++17,c++11', 'warning_level=3'],
 )
 
-inc = include_directories('.')
+# Option to build as header-only library
+header_only = get_option('header_only')
 
-srcs = files('pystring.cpp')
+inc = include_directories('.')
 hdrs = files('pystring.h')
 
-pystring_lib = library(
-    'pystring',
-    srcs,
-    implicit_include_directories: false,
-    include_directories: inc,
-    version: meson.project_version(),
-    install: true,
-)
-pystring_dep = declare_dependency(
-    link_with: pystring_lib,
-    include_directories: inc,
-)
+if header_only
+    # Header-only mode: create a header-only dependency
+    message('Building pystring as header-only library')
+
+    pystring_dep = declare_dependency(
+        include_directories: inc,
+        compile_args: ['-DPYSTRING_HEADER_ONLY'],
+    )
+
+    # Install headers for header-only mode
+    install_headers(hdrs, files('pystring_impl.h'), subdir: 'pystring')
+
+else
+    # Compiled mode: build as normal library
+    message('Building pystring as compiled library')
+
+    srcs = files('pystring.cpp')
+
+    pystring_lib = library(
+        'pystring',
+        srcs,
+        implicit_include_directories: false,
+        include_directories: inc,
+        version: meson.project_version(),
+        install: true,
+    )
+
+    pystring_dep = declare_dependency(
+        link_with: pystring_lib,
+        include_directories: inc,
+    )
+
+    # Install headers for compiled mode
+    install_headers(hdrs, subdir: 'pystring')
+
+    # Generate pkg-config file
+    pkgconfig = import('pkgconfig')
+    pkgconfig.generate(
+        pystring_lib,
+        description: 'C++ functions matching the interface and behavior of python string methods with std::string',
+    )
+endif
+
 meson.override_dependency('pystring', pystring_dep)
 
+# Build and run tests
 test(
     'PyStringTest',
     executable(
@@ -36,11 +69,3 @@ test(
         build_by_default: false,
     ),
 )
-
-install_headers(hdrs, subdir: 'pystring')
-
-pkgconfig = import('pkgconfig')
-pkgconfig.generate(
-    pystring_lib,
-    description: 'C++ functions matching the interface and behavior of python string methods with std::string',
-)

meson_options.txt

@@ -0,0 +1 @@
+option('header_only', type: 'boolean', value: false, description: 'Build as header-only library')