https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119753
--- Comment #9 from Bogdan <love4boobies at yahoo dot com> --- MSVC and ICC do not follow POSIX whatsoever. Everything from default paths to command-line options is different there so I don't think these count. As for EDG, that's true but there is no common ground between its format and that of the other compilers so at the very least I would consider that an EDG issue regardless of whether this is gets resolved in POSIX or preprocessors. It would need to adapt regardless if it wanted to be compliant.