ref: 6b5ef4c2ebd7ad1d58bd740868b2d8f21336ee60
dir: /lib/c/memcpy.c/
#include <string.h>
#undef memcpy
void *
memcpy(void * restrict dst, const void * restrict src, size_t n)
{
char *s1 = dst;
const char *s2 = src;
while (n-- > 0)
*s1++ = *s2++;
return dst;
}