handle language standard target properties

CMake/cotire.cmake

@@ -422,6 +422,27 @@ function (cotire_get_target_compile_flags _config _language _target _flagsVar)
 			endif()
 		endforeach()
 	endif()
+	# handle language standard properties
+	if (_target)
+		get_target_property(_targetLanguageStandard ${_target} ${_language}_STANDARD)
+		get_target_property(_targetLanguageExtensions ${_target} ${_language}_EXTENSIONS)
+		get_target_property(_targetLanguageStandardRequired ${_target} ${_language}_STANDARD_REQUIRED)
+		if (_targetLanguageExtensions)
+			if (CMAKE_${_language}${_targetLanguageExtensions}_EXTENSION_COMPILE_OPTION)
+				list (APPEND _compileFlags "${CMAKE_${_language}${_targetLanguageExtensions}_EXTENSION_COMPILE_OPTION}")
+			endif()
+		elseif (_targetLanguageStandard)
+			if (_targetLanguageStandardRequired)
+				if (CMAKE_${_language}${_targetLanguageStandard}_STANDARD_COMPILE_OPTION)
+					list (APPEND _compileFlags "${CMAKE_${_language}${_targetLanguageStandard}_STANDARD_COMPILE_OPTION}")
+				endif()
+			else()
+				if (CMAKE_${_language}${_targetLanguageStandard}_EXTENSION_COMPILE_OPTION)
+					list (APPEND _compileFlags "${CMAKE_${_language}${_targetLanguageStandard}_EXTENSION_COMPILE_OPTION}")
+				endif()
+			endif()
+		endif()
+	endif()
 	# handle the POSITION_INDEPENDENT_CODE target property
 	if (_target)
 		get_target_property(_targetPIC ${_target} POSITION_INDEPENDENT_CODE)