https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91893
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Also see PR37560: Why do you think the type should be int instead of int:1? The conclusion from C90 DRs was that bit-fields have their own types, and from C99 DRs was to leave whether they have their own types implementation-defined, and GCC follows the C90 DRs and so the assignment has type int:1 and is not promoted as an operand of sizeof. --- CUT --- Basically GCC is following C90 DRs (defect reports) here and is continuing to follow it even in C99 (and later standards); even though those later standards allow for different behavior. Also note again C++ is different from C here.
