第二十三模板 11模板参数提供默认值

//第二十三模板 11模板参数提供默认值

/*#include <iostream>

#include <string>

using namespace std;

//默认参数 class T2=int

template<class T1, class T2=int>

class People

{

public:

	T1 &getx();

	T2 &gety();

	T1 getx()const{ return x;}

	T2 gety()const{ return y;}

	People(const T1&a, const T2&b):x(a),y(b){ cout<<"构造函数执行"<<endl;}

private:

	T1 x;

	T2 y;

};



template<class T1, class T2>

T1&People<T1,T2>::getx()

{

    return x;

}

template<class T1, class T2>

T2&People<T1,T2>::gety(){

   return y;

}

int main()

{

	People<string>one[4]={

	   People<string>("hello world",5),

	   People<string>("good morning",6),

	   People<string>("sit down please",8),

	   People<string>("have a cup of tea",2)	

	};

	int num = sizeof(one)/sizeof(People<string,int>);

	cout<<"输出对像数组one的所有元素"<<endl;

	for(int i=0; i<num; i++){

		cout<<one[i].gety()<<"\t";

		cout<<one[i].getx()<<endl;

	}



	cout<<"修改one[3]的数据并输出"<<endl;

	one[3].getx()="gertie's fab eat";//有点不能理解，这里为什么能直接的用=赋值给getx呢

	one[3].gety()=6;

	cout<<one[3].gety()<<":\t";

	cout<<one[3].getx()<<endl;

}*/