memmove
(功能)Moves one buffer to another.
(函数参数)void *memmove( void *dest, const void *src, size_t count );
(返回值)memmove returns the value of dest.
#include<windows.h>
#include<assert.h>
void* my_memmove(void* dest,const void* str, size_t sz)
{
assert(dest != NULL);
assert(str != NULL);
void* ret = dest;
if (dest < str)
{
while (sz--)
{
*(char*)dest = *(char*)str;
dest = (char*)dest + 1;
str = (char*)str + 1;
}
}
else
{
while (sz--)
{
*((char*)dest+sz) = *((char*)str+sz);//代码的巧妙之处,同过sz的--实现了,指针的变动
}
}
return ret;
}
int main()
{
int arr[9] = {1,2,3,4,5,6,7,8,9};
my_memmove(arr,arr+2, 4 * sizeof(arr[0]));
system("pause");
return 0;
}