内存赋值memcpy实现

#include <stdio.h>#include <assert.h>void *memcpy(void *memTo, const void *memFrom, size_t size) // typedef  unsinged int  size_t 其大小足以保证存储内存中对象的大小{assert((memTo != NULL) && (memFrom != NULL));char *tempFrom = (char*) memFrom;char *tempTo = (char*) memTo;while(size-- > 0){*tempTo++ = *tempFrom++;}return memTo;}int main(){char strSrc[] = "hello World!";char strDest[20];memcpy(strDest,strSrc,4);strDest[4] = '\0';printf("strDest:%s\n",strDest);return 0;}