Windows IntelLLVM emits `-Qstd=` flags that cause compiler warnings. This is annoying in general and a problem when using COMPILE_WARNING_AS_ERROR. This is observed with generators MinGW Makefiles and Ninja. This is not observed with generator Visual Studio 17 2022. However, @brad.king notes that > We *strongly* prefer the `-` style options over `/` because they work better with makefiles that use the MSYS shell. ```cmake cmake_minimum_required(VERSION 3.21) project(dummy LANGUAGES CXX) set(CMAKE_CXX_STANDARD 11) set(cpp_src "${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp") file(WRITE ${cpp_src} "int main() { return 0; }") add_executable(dummy_cpp ${cpp_src}) ``` ``` -- The CXX compiler identification is IntelLLVM 2023.0.0 with MSVC-like command-line ``` Ninja: ``` [1/2] Building CXX object CMakeFiles\dummy_cpp.dir\dummy.cpp.obj icx: warning: argument unused during compilation: '-Qstd:c++11' [-Wunused-command-line-argument] [2/2] Linking CXX executable dummy_cpp.exe ``` MinGW Makefiles: ``` [ 50%] Building CXX object CMakeFiles/dummy_cpp.dir/dummy.cpp.obj icx: warning: argument unused during compilation: '-Qstd=c++11' [-Wunused-command-line-argument] [100%] Linking CXX executable dummy_cpp.exe [100%] Built target dummy_cpp ```