operator重载的使用

C++的大多数运算符都可以通过operator来实现重载。

简单的operator+

#include <iostream>
using namespace std;

class A
{
public:
    A(int x){i=x;}
    int i;
    A &operator+(A &p)
    {
        this->i+=p.i;
        return *this;
    }
};

void main()
{
    A a(10),b(20),c(0);
    c=a+b;
    cout<<c.i<<endl;
    system("pause");
}

简单的operator++

#include <iostream>
using namespace std;

class A
{
public:
    A(int x){i=x;}
    int i;
    A &operator++()
    {
        this->i++;
        return *this;
    }
};

void main()
{
    A a(10);
    a++;
    cout<<a.i<<endl;
    system("pause");
}

深层operator=

#include <iostream>
using namespace std;

class A
{
public:
    A(int x){i=new int;*i=x;}
    ~A(){delete i;i=0;}
    A(const A&p)
    {
        i=new int;
        *i=*(p.i);
    }
    int *i;
    A &operator=(A &p)
    {
        *i=*(p.i);
        return *this;
    }
    int pp(){return *i;}
};

void main()
{
    A a(10),b(0);
    a=b;
    cout<<a.pp()<<endl;
    system("pause");
}