Create a CMake target upon install

CMakeLists.txt

@@ -1,15 +1,19 @@
 
-cmake_minimum_required(VERSION 3.3)
-cmake_policy(SET CMP0092 NEW)
+cmake_minimum_required(VERSION 3.5)
+cmake_policy(SET CMP0076 NEW) # remove warning for target_sources(flux...) for < 3.13
+cmake_policy(SET CMP0092 NEW) # remove warning for CMAKE_LANG_FLAG MSVC for < 3.15
 
 project(libflux CXX)
 
+include(GNUInstallDirs)
+include(CMakePackageConfigHelpers)
+
+
 set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
 
 add_library(flux INTERFACE)
-target_sources(flux INTERFACE
-    ${CMAKE_CURRENT_SOURCE_DIR}/include/flux.hpp
-)
+file(GLOB_RECURSE FLUX_HPPS RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" "${CMAKE_CURRENT_SOURCE_DIR}/include/*.hpp" )
+target_sources(flux INTERFACE $<BUILD_INTERFACE:${FLUX_HPPS}>)
 
 if (MSVC)
     target_compile_features(flux INTERFACE cxx_std_23)
@@ -18,7 +22,12 @@ else()
     target_compile_features(flux INTERFACE cxx_std_20)
 endif()
 
-target_include_directories(flux INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_include_directories(
+    flux 
+    INTERFACE 
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+)
 
 set(CMAKE_CXX_EXTENSIONS Off)
 
@@ -55,4 +64,58 @@ endif()
 
 if (${FLUX_BUILD_MODULE})
     add_subdirectory(module)
-endif()
+endif()
+
+set(PORT_NAME flux)
+set(CONFIG_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PORT_NAME}")
+
+# header-only doesn't need architeture differences so clear CMAKE_SIZEOF_VOIDP
+# temporarily when creating the version file.
+set(ORIGINAL_CMAKE_SIZEOF_VOIDP ${CMAKE_SIZEOF_VOIDP})
+set(CMAKE_SIZEOF_VOIDP "")
+write_basic_package_version_file(
+    "${PROJECT_BINARY_DIR}/${PORT_NAME}-version.cmake"
+    VERSION -1 # When there is a PROJECT_VERSION, remove this line
+    COMPATIBILITY SameMajorVersion
+    # ARCH_INDEPENDENT # showed up in CMake 3.14 and gets rid of the need to do the CMAKE_SIZEOF_VOIDP thing
+)
+set(CMAKE_SIZEOF_VOIDP ${ORIGINAL_CMAKE_SIZEOF_VOIDP})
+
+configure_package_config_file(
+    "${PROJECT_SOURCE_DIR}/cmake/${PORT_NAME}-config.cmake.in"
+    "${PROJECT_BINARY_DIR}/${PORT_NAME}-config.cmake"
+    INSTALL_DESTINATION "${CONFIG_DESTINATION}"
+    NO_SET_AND_CHECK_MACRO
+    NO_CHECK_REQUIRED_COMPONENTS_MACRO
+)
+
+# set target installation location properties and associates it with the targets files
+install(
+    TARGETS ${PORT_NAME}
+    EXPORT ${PORT_NAME}-targets
+    ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+    LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+    RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
+)
+
+#install the targets files
+install(
+    EXPORT ${PORT_NAME}-targets
+    NAMESPACE ${PORT_NAME}::
+    DESTINATION "${CONFIG_DESTINATION}"
+)
+
+# install the config and version files
+install(
+    FILES
+        "${PROJECT_BINARY_DIR}/${PORT_NAME}-config.cmake"
+        "${PROJECT_BINARY_DIR}/${PORT_NAME}-version.cmake"
+    DESTINATION "${CONFIG_DESTINATION}"
+)
+
+# install the headers
+install(
+    DIRECTORY "${PROJECT_SOURCE_DIR}/include"
+    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/.."
+    PATTERN "build2file" EXCLUDE
+)

cmake/flux-config.cmake.in

@@ -0,0 +1,3 @@
+@PACKAGE_INIT@
+include("${CMAKE_CURRENT_LIST_DIR}/flux-targets.cmake")
+list(APPEND CMAKE_MODULE_PATH "@PACKAGE_cmakeModulesDir@")