Hi Linus, here is an idea:
a test for integer constant expressions which returns an integer constant expression itself which should be suitable for passing to __builtin_choose_expr might be: #define ICE_P(x) (sizeof(int) == sizeof(*(1 ? ((void*)((x) * 0l)) : (int*)1))) This also does not evaluate x itself on gcc although this is not guaranteed by the standard. (And I haven't tried any older gcc.) Best, Martin
