This is a feature request for adding a preprocessor switch that allows one to disable the inclusion of the std::filesystem header in std.h.

The problem is that some video game console SDKs do not support std::filesystem, but ship the <filesystem> header. Therefore FMT_HAS_INCLUDE returns true, but the <filesystem> header provided by the SDK contains an #error directive breaking the build.

I'd appreciate the inclusion of a preprocessor switch (e.g. FMT_DISABLE_STD_FILESYSTEM) which can be set prior including std.h to work around this issue.