Use CMakePackageConfigHelpers, make websocketpp-config.cmake.in relocatable

CMakeLists.txt

@@ -259,8 +259,16 @@ print_used_build_config()
 
 export (PACKAGE websocketpp)
 
-configure_file (websocketpp-config.cmake.in "${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/websocketpp-config.cmake" @ONLY)
-configure_file (websocketpp-configVersion.cmake.in "${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/websocketpp-configVersion.cmake" @ONLY)
+include(CMakePackageConfigHelpers)
+configure_package_config_file(websocketpp-config.cmake.in
+  "${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/websocketpp-config.cmake"
+  PATH_VARS INSTALL_INCLUDE_DIR
+  INSTALL_DESTINATION "${INSTALL_CMAKE_DIR}"
+  NO_CHECK_REQUIRED_COMPONENTS_MACRO
+)
+write_basic_package_version_file("${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/websocketpp-configVersion.cmake"
+  VERSION ${WEBSOCKETPP_VERSION}
+  COMPATIBILITY ExactVersion)
 
 # Install the websocketpp-config.cmake and websocketpp-configVersion.cmake
 install (FILES

websocketpp-config.cmake.in

@@ -3,5 +3,6 @@
 #  WEBSOCKETPP_FOUND - indicates that the module was found
 #  WEBSOCKETPP_INCLUDE_DIR - include directories
 
+@PACKAGE_INIT@
+set_and_check(WEBSOCKETPP_INCLUDE_DIR "@PACKAGE_INSTALL_INCLUDE_DIR@")
 set(WEBSOCKETPP_FOUND TRUE)
-set(WEBSOCKETPP_INCLUDE_DIR "@INSTALL_INCLUDE_DIR@")

websocketpp-configVersion.cmake.in

@@ -1,11 +0,0 @@
-set(PACKAGE_VERSION "@WEBSOCKETPP_VERSION@")
-
-# Check whether the requested PACKAGE_FIND_VERSION is compatible
-if("${PACKAGE_VERSION}" VERSION_LESS "${PACKAGE_FIND_VERSION}")
-  set(PACKAGE_VERSION_COMPATIBLE FALSE)
-else()
-  set(PACKAGE_VERSION_COMPATIBLE TRUE)
-  if ("${PACKAGE_VERSION}" VERSION_EQUAL "${PACKAGE_FIND_VERSION}")
-    set(PACKAGE_VERSION_EXACT TRUE)
-  endif()
-endif()