1 _Static_assert(__builtin_isdigit('0')); 2 _Static_assert(__builtin_isdigit('9')); 3 4 _Static_assert(!__builtin_isdigit(0)); 5 _Static_assert(!__builtin_isdigit(' ')); 6 _Static_assert(!__builtin_isdigit('z')); 7 8 /* 9 * check-name: builtin_isdigit 10 */ 11