运算符++重载

       运算符重载中，后++(--)需要int参数，前置++(--)则不需要。输入输出重载需定义为友元类型。

#include"iostream"#include"vector"#include"string"using namespace std;class base{int data;public:base(int i){ data = i; cout << "base"<<endl; }};class test:public base {int data;public:explicit test(int i = 0, int j = 0) :base(j), data(i){ cout << "test" << endl; };friend test operator ++(test& a){//前置a.data = a.data + 10;return a;}friend test operator ++(test& a, int){//后置test old(a);a.data = a.data + 1;return old;}friend ostream& operator<<(ostream& out,const test & t){out << t.data<<endl;return out;}};void main(){test t(1, 2);cout << t++<<t;cout << ++t << endl;system("pause");}