Wink Saville <wink@xxxxxxxxxxx> writes: > Should we add a "_Static_assert" that sizeof(uintmax_t) >= sizeof(uint64_t) ? If that expression compiles, then both types are understood by the platform. Because http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdint.h.html tells us: Greatest-width integer types The following type designates a signed integer type capable of representing any value of any signed integer type: intmax_t The following type designates an unsigned integer type capable of representing any value of any unsigned integer type: uintmax_t These types are required. we know what that expression evaluates to, no?