https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108097
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to cqwrteur from comment #5) > Still crashing by replacing with std::cout Yes, of course, which is why you should have used that in the first place. Your own fast_io.h is irrelevant to the problem. (In reply to cqwrteur from comment #6) > std::cout and stdio bloat my binary. Yes, I know, you never stop going on about it. You don't need to optimize the binary size of reproducers posted in bugzilla though, do you? The point should be to demonstrate the problem effectively, not minimise binary size. Nobody is going to download your fast_io.h to reproduce a bug.