fix: set CMAKE_CXX_STANDARD_REQUIRED

CMakeLists.txt

@@ -9,6 +9,7 @@ include(GNUInstallDirs)
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE CACHE BOOL