https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103305
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #5) > static const mask blank = space; We might want to use blank = _ISspace | _ISblank for this last one, but I don't really understand what newlib defines those categories as: #define isblank(__c) \ __extension__ ({ __typeof__ (__c) __x = (__c); \ (__ctype_lookup(__x)&_B) || (int) (__x) == '\t';}) (__ctype_lookup(__x)&_ISblank) || (int) (__x) == '\t';}) This definition is weird ... why is '\t' not already handled by _ISblank?