00170.c (1294B)
1 #include <stdio.h> 2 3 enum fred 4 { 5 a, 6 b, 7 c, 8 d, 9 e = 54, 10 f = 73, 11 g, 12 h 13 }; 14 15 /* All following uses of enum efoo should compile 16 without warning. While forward enums aren't ISO C, 17 it's accepted by GCC also in strict mode, and only warned 18 about with -pedantic. This happens in the real world. */ 19 /* Strict ISO C doesn't allow this kind of forward declaration of 20 enums, but GCC accepts it (and gives only pedantic warning), and 21 it occurs in the wild. */ 22 enum efoo; 23 struct Sforward_use { 24 int (*fmember) (enum efoo x); 25 }; 26 27 extern enum efoo it_real_fn(void); 28 enum efoo { 29 ONE, 30 TWO, 31 }; 32 struct S2 { 33 enum efoo (*f2) (void); 34 }; 35 void should_compile(struct S2 *s) 36 { 37 s->f2 = it_real_fn; 38 } 39 40 enum efoo it_real_fn(void) 41 { 42 return TWO; 43 } 44 45 static unsigned int deref_uintptr(unsigned int *p) 46 { 47 return *p; 48 } 49 50 enum Epositive { 51 epos_one, epos_two 52 }; 53 54 int main() 55 { 56 enum fred frod; 57 enum Epositive epos = epos_two; 58 59 printf("%d %d %d %d %d %d %d %d\n", a, b, c, d, e, f, g, h); 60 /* printf("%d\n", frod); */ 61 frod = 12; 62 printf("%d\n", frod); 63 frod = e; 64 printf("%d\n", frod); 65 66 /* Following should compile without warning. */ 67 printf ("enum to int: %u\n", deref_uintptr(&epos)); 68 69 return 0; 70 } 71 72 /* vim: set expandtab ts=4 sw=3 sts=3 tw=80 :*/