std::memcpy(arr_copy, arr[0], sizeof arr); , on the other hand, causes undefined behavior (at least in C++; not entirely sure about C). ... <看更多>

glibc/string/memcpy.c ... The GNU C Library is free software; you can redistribute it and/or ... memcpy (void *dstpp, const void *srcpp, size_t len). ... <看更多>

不同的CPU架構, 指令集, OS, Compiler和memcpy function都會影響效率. 不確定你用的C library裡面的memcpy是怎麼寫的, 單就你結論提到差距10倍的 ... ... <看更多>

... <看更多>