ref: 560a156341e5bb352194a85c3258406a079697b7
dir: /tests/cc/execute/0205-cpparg.c/
#define TOLOWER(c) ((((unsigned)c) - 'A' < 26) ? ((c) | 32) : (c)) int main(void) { char c, *s = "Bla"; c = TOLOWER((unsigned char)*s); if (c != 'b') return 1; return 0; }