Right, the memcpy() API is leaky because it leaves some things unspecified. You can deduce the implementation by providing various inputs to it that have "undef

Right, the memcpy() API is leaky because it leaves some things unspecified. You can deduce the implementation by providing various inputs to it that have "undefined behavior". This is a common problem in C, and there are usually functions that avoid it (Linus recommends memmove).