Fixed CMake build on 2.8 versions

CMakeLists.txt

@@ -147,37 +147,37 @@ add_subdirectory(test)
 set(GLM_INSTALL_CONFIGDIR "${CMAKE_INSTALL_LIBDIR}/cmake/glm")
 install(DIRECTORY glm DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
-include(CMakePackageConfigHelpers)
+if (NOT CMAKE_VERSION VERSION_LESS "2.8.12")
-write_basic_package_version_file(
+	include(CMakePackageConfigHelpers)
+	write_basic_package_version_file(
 	    "${CMAKE_CURRENT_BINARY_DIR}/glmVersion.cmake"
 	    VERSION ${GLM_VERSION}
 	    COMPATIBILITY AnyNewerVersion
-)
+	)
 
-# build tree package config
+	# build tree package config
-configure_file(
+	configure_file(
 	    cmake/glmBuildConfig.cmake.in
 	    glmConfig.cmake
 	    COPYONLY
-)
+	)
 
-# install tree package config
+	# install tree package config
-configure_package_config_file(
+	configure_package_config_file(
 	    cmake/glmConfig.cmake.in
 	    ${GLM_INSTALL_CONFIGDIR}/glmConfig.cmake
 	    INSTALL_DESTINATION ${GLM_INSTALL_CONFIGDIR}
 	    PATH_VARS CMAKE_INSTALL_INCLUDEDIR
 	    NO_CHECK_REQUIRED_COMPONENTS_MACRO
-)
+	)
 
-install(
+	install(
 	    FILES 
 	        "${CMAKE_CURRENT_BINARY_DIR}/glmConfig.cmake"
 	        "${CMAKE_CURRENT_BINARY_DIR}/glmVersion.cmake"
 	    DESTINATION ${GLM_INSTALL_CONFIGDIR}
-)
+	)
 
-if (NOT CMAKE_VERSION VERSION_LESS "2.8.12")
     add_library(glm INTERFACE)
     target_include_directories(glm INTERFACE
         $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>