1 const char *str = "12345678901234567890";
3 char str1[20], str2[20], str3[20];
5 char *duff_copy(char *dst, const char *from, int count)
11 case 0: do{ *to++ = *from++;
12 case 7: *to++ = *from++;
13 case 6: *to++ = *from++;
14 case 5: *to++ = *from++;
15 case 4: *to++ = *from++;
16 case 3: *to++ = *from++;
17 case 2: *to++ = *from++;
18 case 1: *to++ = *from++;
24 int main(int argc, char *argv[])
26 printf("duff's Device 15 : %s\n", duff_copy(str1, str, 15));
27 printf("duff's Device 3 : %s\n", duff_copy(str2, str, 3));
28 printf("duff's Device 8 : %s\n", duff_copy(str2, str, 8));