自訂一個memcpy (c++)

#include <iostream>
using namespace std;
void *memcpy2(void *dest, const void *ori, int size);
int main(void){
        char tmp[] = "adfadfaf";
        memcpy2(tmp, "hello world",4);
        tmp[4]='\0';
        cout<<tmp;
        return 0;
}
void *memcpy2(void *dest, const void *ori, int size){
        assert(dest!=NULL && ori !=NULL);
        char *dest2= (char *) dest;
        char *ori2= (char *) ori;
        for(int i=0; i< size; i++){
                *dest2++ = *ori2++;
        }
        return dest2;
}