ref: a115b80c0660473027f0a4ae009b7534e8d5f8d8
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; }