ref: eeec7382051ef8c9e894e7c229dfe0dfb2ea2921
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;
}