交换两个指针(c++)

ptrSwap.cpp

#include <iostream>

using namespace std;

//using pointer
void ptrSwap1(int **pa,int **pb)
{
    int *ptmp = *pa;
    *pa = *pb;
    *pb = ptmp;
}

//using  reference
void ptrSwap2(int *&pa,int *&pb)
{
    int *pk = pa;
    pa = pb;
    pb = pk;
}

int main()
{
    for(int i=1; i<=3; ++i)
    {
        int a=56,b=78;
        int *pa=&a,*pb=&b;
        cout<<"a : "<<a<<"\tb : "<<b<<endl;
        cout<<"*pa : "<<*pa<<"\t*pb : "<<*pb<<endl;
        cout<<"pa : "<<pa<<"\tpb : "<<pb<<endl;
        switch(i)
        {
        case 1:
           //using pointer
            ptrSwap1(&pa,&pb);
            break;
        case 2:
            //using  reference
            ptrSwap2(pa,pb);
            break;
        default:
            //using std::swap
            swap(pa,pb);
            break;
        }
        cout<<"a : "<<a<<"\tb : "<<b<<endl;
        cout<<"*pa : "<<*pa<<"\t*pb : "<<*pb<<endl;
        cout<<"pa : "<<pa<<"\tpb : "<<pb<<endl<<endl;
    }
}