make the project cmakeable + pkgconfig. zero deps

CMakeLists.txt

@@ -0,0 +1,124 @@
+cmake_minimum_required(VERSION 3.14...3.22)
+
+set(THE_constexpr-to-string_VERSION 1.0.1)
+
+if(constexpr-to-string_TEST_INSTALLED_VERSION)
+    project(
+    constexpr-to-string_test_installation
+    VERSION ${THE_constexpr-to-string_VERSION}
+    LANGUAGES CXX)
+
+    find_package(constexpr-to-string ${THE_constexpr-to-string_VERSION} REQUIRED)
+
+    message("constexpr-to-string_FOUND: ${constexpr-to-string_FOUND}")
+
+    file(WRITE "${CMAKE_BINARY_DIR}/${PROJECT_NAME}dummy_target.cpp"
+       "#include <constexpr-to-string/to_string.hpp>\nint main() {}\n")
+
+    add_executable(dummy_target
+                 "${CMAKE_BINARY_DIR}/${PROJECT_NAME}dummy_target.cpp")
+
+    target_link_libraries(dummy_target
+                        PRIVATE constexpr-to-string::constexpr-to-string)
+
+    find_package(PkgConfig)
+
+    pkg_check_modules(constexpr-to-string GLOBAL IMPORTED_TARGET
+                    constexpr-to-string)
+
+    file(WRITE "${CMAKE_BINARY_DIR}/${PROJECT_NAME}dummy_target2.cpp"
+       "#include <constexpr-to-string/to_string.hpp>\nint main() {}\n")
+
+    add_executable(dummy_target2
+                 "${CMAKE_BINARY_DIR}/${PROJECT_NAME}dummy_target2.cpp")
+
+    target_link_libraries(dummy_target2 PRIVATE PkgConfig::constexpr-to-string)
+    return()
+endif()
+
+project(
+  constexpr-to-string
+  VERSION ${THE_constexpr-to-string_VERSION}
+  LANGUAGES CXX)
+
+# ---- Include guards ----
+
+if(PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
+    message(
+    FATAL_ERROR
+      "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there."
+  )
+endif()
+
+# ---- Add source files ----
+
+# Note: globbing sources is considered bad practice as CMake's generators may
+# not detect new files automatically. Keep that in mind when changing files, or
+# explicitly mention them here.
+file(
+  GLOB_RECURSE headers
+  RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+  CONFIGURE_DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/include/*.hpp")
+
+# ---- Create library ----
+
+add_library(${PROJECT_NAME} INTERFACE)
+add_library(${PROJECT_NAME}::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
+set_target_properties(${PROJECT_NAME} PROPERTIES CXX_STANDARD 14)
+
+target_include_directories(
+  ${PROJECT_NAME} INTERFACE $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+                            $<INSTALL_INTERFACE:include>)
+
+# ---- Installation logic ----
+
+include(GNUInstallDirs)
+include(CMakePackageConfigHelpers)
+
+install(DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/include/${PROJECT_NAME}
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+install(
+  TARGETS ${PROJECT_NAME}
+  EXPORT ${PROJECT_NAME}Targets
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+install(
+  EXPORT ${PROJECT_NAME}Targets
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/${PROJECT_NAME}/
+  NAMESPACE ${PROJECT_NAME}::)
+
+file(
+  WRITE "${CMAKE_BINARY_DIR}/${PROJECT_NAME}Config.cmake.in"
+  "@PACKAGE_INIT@\ninclude(\$\{CMAKE_CURRENT_LIST_DIR\}/${PROJECT_NAME}Targets.cmake)"
+)
+
+configure_package_config_file(
+  ${CMAKE_BINARY_DIR}/${PROJECT_NAME}Config.cmake.in
+  ${CMAKE_BINARY_DIR}/${PROJECT_NAME}Config.cmake
+  INSTALL_DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/${PROJECT_NAME})
+
+install(FILES "${CMAKE_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
+        DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/${PROJECT_NAME})
+
+write_basic_package_version_file(
+  ${CMAKE_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+  VERSION ${PROJECT_VERSION}
+  COMPATIBILITY AnyNewerVersion ARCH_INDEPENDENT)
+
+install(FILES "${CMAKE_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
+        DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/${PROJECT_NAME})
+
+file(
+  GENERATE
+  OUTPUT "${CMAKE_BINARY_DIR}/${PROJECT_NAME}.pc"
+  CONTENT
+    "prefix=${CMAKE_INSTALL_PREFIX}\nincludedir=\$\{prefix\}/include\nName: ${PROJECT_NAME}\nDescription:  C++14 code to convert integers to strings at compile-time \nVersion: ${PROJECT_VERSION}\nCflags: -I\$\{includedir\}\n"
+)
+
+install(FILES "${CMAKE_BINARY_DIR}/${PROJECT_NAME}.pc"
+        DESTINATION ${CMAKE_INSTALL_DATADIR}/pkgconfig)
+
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+    include(CPack)
+endif()