Strcpy与memcpy两函数的实现

char *strcpy(char *des, const char *src){

       assert((des != NULL) && (src != NULL));

       char *add = des;

       while ((*des++ = *src++) != ‘/0’) ;

return des;

}

 

void *memcpy(void *pvTo, const void *pvFrom, size_t size) {

       assert((pvTo != NULL) && (pvFrom != NULL));      // 使用断言

       byte *pbTo = (byte *) pvTo;         // 防止改变pvTo的地址

       byte *pbFrom = (byte *) pvFrom; // 防止改变pvFrom的地址

       while(size -- > 0 )

              *pbTo ++ = *pbFrom ++ ;

       return pvTo;

}