#include <iostream.h>
/*指向函數(shù)的指針*/
typedef int (*pFun)(int, int);
int Max(int a, int b)
{
    return a > b ? a : b;
}
int Min(int a, int b)
{
    return a < b ? a : b;
}
/*通用接口函數(shù)，實(shí)現(xiàn)對(duì)其他函數(shù)的封裝*/
int Result(pFun fun, int a, int b)
{
    return (*fun)(a, b);
}
void main()
{
    int a = 3;
    int b = 4;
    cout<<"Test function pointer: "<<endl;
    cout<<"The maximum number between a and b is "<<Result(Max, a, b)<<endl;
    cout<<"The minimum number between a and b is "<<Result(Min, a, b)<<endl;
}

#include <iostream.h>

    class CA;

    /*指向類的非靜態(tài)成員函數(shù)的指針*/
    typedef int (CA::*pClassFun)(int, int);

    /*指向一般函數(shù)的指針*/
    typedef int (*pGeneralFun)(int, int);

    class CA
    {
    public:

        int Max(int a, int b)
        {
            return a > b ? a : b;
        }

        int Min(int a, int b)
        {
            return a < b ? a : b;
        }

        static int Sum(int a, int b)
        {
            return a + b;
        }

        /*類內(nèi)部的接口函數(shù)，實(shí)現(xiàn)對(duì)類的非靜態(tài)成員函數(shù)的封裝*/
        int Result(pClassFun fun, int a, int b)
        {
            return (this->*fun)(a, b);
        }

    };

    /*類外部的接口函數(shù)，實(shí)現(xiàn)對(duì)類的非靜態(tài)成員函數(shù)的封裝*/
    int Result(CA* pA, pClassFun fun, int a, int b)
    {
        return (pA->*fun)(a, b);
    }

    /*類外部的接口函數(shù)，實(shí)現(xiàn)對(duì)類的靜態(tài)成員函數(shù)的封裝*/
    int GeneralResult(pGeneralFun fun, int a, int b)
    {
        return (*fun)(a, b);
    }

   
    void main()
    {
        CA ca;
        int a = 3;
        int b = 4;

        cout<<"Test nonstatic member function pointer from member function:"<<endl;
        cout<<"The maximum number between a and b is "<<ca.Result(CA::Max, a, b)<<endl;
        cout<<"The minimum number between a and b is "<<ca.Result(CA::Min, a, b)<<endl;

        cout<<endl;
        cout<<"Test nonstatic member function pointer from external function:"<<endl;
        cout<<"The maximum number between a and b is "<<Result(&ca, CA::Max, a, b)<<endl;
        cout<<"The minimum number between a and b is "<<Result(&ca, CA::Min, a, b)<<endl;

        cout<<endl;
        cout<<"Test static member function pointer: "<<endl;
        cout<<"The sum of a and b is "<<GeneralResult(CA::Sum, a, b)<<endl;
    }