引用实现指针交换

#include <iostream>
using namespace std;

void exchange(int* &rpa, int* &rpb)
{
    int *t;
    t = rpa;
    rpa = rpb;
    rpb = t;
}
int main(int argc, const char * argv[]) {
    int *pa, *pb;
    int a =10, b = 20;
    pa = &a; pb =&b;
    cout << "pa:"<< pa <<", pb:"<<pb<<endl;
    exchange(pa,pb);
    cout << "pa:"<< pa <<", pb:"<<pb<<endl;
    return 0;
}

pa:0x7ffeefbff45c, pb:0x7ffeefbff458
pa:0x7ffeefbff458, pb:0x7ffeefbff45c