实现memcpy函数

 1 #include <stdio.h>
 2 #include <assert.h>
 3 #include <stdlib.h>
 4 
 5 void *memcpy(void * des,void const *src,size_t len);
 6 void print(int *data,size_t n); 
 7 
 8 int main(void)
 9 {
10         int des[11];
11         int src[11]={0,1,2,3,4,5,6,7,8,9,10};
12     
13         print(des,10);
14         memcpy(des,src,sizeof(src));
15         print(des,10);
16 
17         return 1;
18 }
19 
20 void print(int *data, size_t n)
21 {
22     
23         int i=0;
24         printf("\n");
25         for(;i<n;i++)
26         printf("%d ",data[i]);
27 
28         printf("\n");
29 }
30 
31 void *memcpy(void *des,const void *src,size_t len)
32 {
33         char * result =des;
34         const char * from = src;
35         assert(des&&src);
36         while(len--)
37         {   
38                 *(result++) = *(from++);
39         }   
40         return des;
41 }