How to enable C++17 in CMake
Your approach is the correct one, but it will not work for MSVC on versions of CMake prior to 3.10.
From the CMake 3.9 documentation:
For compilers that have no notion of a standard level, such as MSVC, this has no effect.
In short, CMake haven't been updated to accommodate for the standard flags added to VC++ 2017.
You have to detect if VC++ 2017 (or later) is used and add the corresponding flags yourself for now.
In CMake 3.10 (and later) this have been fixed for newer version of VC++. See the 3.10 documentation.
Modern CMake propose an interface for this purpose target_compile_features
.
Documentation is here: Requiring Language Standards
Use it like this:
target_compile_features(${TARGET_NAME} PRIVATE cxx_std_17)
In modern CMake, I've found it best to assign CXX standards at the target level instead of global variable level and use the built in properties (seen here: https://cmake.org/cmake/help/latest/manual/cmake-properties.7.html) to keep it compiler agnostic.
For Example:
set_target_properties(FooTarget PROPERTIES
CXX_STANDARD 17
CXX_EXTENSIONS OFF
etc..
)