https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90081
--- Comment #2 from Guy Perfect <bafap5 at yahoo dot com> --- The issue is not resolved based on the merits of the out-of-range values used in the earlier examples. Type resolution still fails in the current implementation, as demonstrated below: int x = sizeof ((int8_t) 5); /* Correct, gives 1 */ int y = sizeof (INT8_C(5)); /* Incorrect, gives 4 */ In this case, INT8_C is required to evaluate to type int_least8_t, which cannot be larger than the smallest integer type able to represent the range of the type int8_t: "The typedef name int_least N _t designates a signed integer type with a width of at least N, such that no signed integer type with lesser size has at least the specified width." int8_t can be represented exactly using 1 byte, as shown by the cast. For the sizeof test to give 4 on the macro demonstrates that the macro is implemented incorrectly. A cast is still strongly encouraged (if not necessary) in order for these macros to be compliant with the stdint.h specification.
