On Wed, 27 Jan 2021 at 20:54, Barry Revzin via Liaison <firstname.lastname@example.org> wrote:Eric Niebler actually asked this on StackOverflow a few years ago: https://stackoverflow.com/q/48045470/2069064The accepted answer there is:
#define PP_THIRD_ARG(a,b,c,...) c #define VA_OPT_SUPPORTED_I(...) PP_THIRD_ARG(__VA_OPT__(,),true,false,) #define VA_OPT_SUPPORTED VA_OPT_SUPPORTED_I(?)Who is going to remember that without having to look it up though?The #ifdef __VA_OPT__ solution was my first thought, it's unfortunate we forbid it. If we can't have that then I think we do need a feature test macro. The voodoo above will make most developers wish they were using Rust.