一个输出运算符与递增运算符重载的问题

2018-12-14 11:01:44 214 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

C++类与对象笔记十二：运算符重载三：递增运算符重载先看看系统自带的递增运算符++ // 递增运算符重载 ++； a++; ++a int a = 10; cout << ++a << endl; // 11 先加，后输出。 cout << a << endl; // 11 已加。 int b = 10; cout << b++ << endl; // 10 先输出，然后再加。 cout << b << endl; // 阅读详情

#include <iostream>
#include <string>
using namespace std;

class Person
{
private:
string name;
int age;

public:
Person(string str, int age)
{
this->name = str;
this->age = age;
}
Person &operator++()
{
this->age++;
return *this;
}
Person operator++(int)
{
Person temp = *this;
this->age++;
return temp;
}
friend ostream &operator<<(ostream &cout, Person &person);

};
ostream &operator<<(ostream &cout, Person &person)
{
cout << "name: " << person.name << " age: " << person.age;
return cout;
}

int main()
{
Person p1 = {"zhang", 14};
Person p2 = {"wang", 23};

cout << ++p1 << endl;
cout << p1 << endl;
cout << "-----------" << endl;
cout << p2++ << endl; //报错，没有匹配操作符
cout << p2 << endl;

cin.get();
return 0;
}

为什么cout<<p2++<<endl;的时候报错，提示没有匹配操作符 std::ostream << Person
问题是我已经重载了<<，cout<<++p1<<endl;就不会报错

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