【8.17】建立一个用来实现求3个数和的类模板（将成员函数定义在类模板的内部），并写出调用此类模板的完整程序。

#include<iostream>

using namespace std;

template<typename T1,typename T2,typename T3>

class sum

{

T1 x;

T2 y;

T3 z;

public:

sum(T1 a,T2 b,T3 c)

{

x=a;y=b;z=c;

}

void gettersum()

{

cout<<x+y+z<<endl;

}

T1 getterx()

{

return x;

}

T2 gettery()

{

return y;

}

T3 getterz()

{

return z;

}

};

int main()

{

sum<double,double,double>a(1.4,1.7,1.3);

cout<<a.getterx()<<","<<a.gettery()<<","<<a.getterz()<<"三个数之和为:";

a.gettersum();

sum<int,double,float>b(5,2.2,4.7);

cout<<b.getterx()<<","<<b.gettery()<<","<<b.getterz()<<"三个数之和为:";

b.gettersum();

return 0;

}

运行结果：