451 implementation of memcpy, memmove and memset

1、memcpy and memmove The role of & difference

1.1、memcpy

memcpy and memmove All are C Library functions in languages , Included in header file string.h in .

void * memcpy ( void * destination, const void * source, size_t num );

memcpy The role of ：

• hold source At the position pointed by the pointer num A memory block of bytes is copied to destination Where the pointer points .
• The memory area pointed to by the source pointer and the destination pointer is not allowed to overlap , Will not be safe <