On Sat, Aug 03, 2019 at 09:30:59AM +0200, Aaron wrote: > Can I thrust in GCC doing the right thing when casting to a wider type > in C, now and in the future? Yes. There can be bugs, of course. > Unfortunately, it is not valid C due to the effective type rules. (6.5 > Expression 7). > // this is safe due to the check: if(... > above No it's not. It likely isn't valid code (unless d and s happen to always point to things with effective type int here). > *(unsigned*)d=*(const unsigned*)s; // <===== > line in question If you don't like 6.5/7, and you don't mind slower code, you can use -fno-strict-aliasing . Segher
