8.17~8.18

#include<iostream>
using namespace std;
template<typename T>
class Add_3
{
public:
	Add_3(T a,T b,T c)
	{x=a;y=b;z=c;}
	T sum()
	{return x+y+z;}
private:
	T x,y,z;
};
int main()
{
	Add_3<int>sum3_1(1,4,7);
	Add_3<float>sum3_2(2.0,3.5,5.3);
	Add_3<double>sum3_3(4,5,6);
	cout<<"三个整数之和是:"<<sum3_1.sum()<<endl;
	cout<<"三个单精度数之和是:"<<sum3_2.sum()<<endl;
	cout<<"三个双精度数之和是:"<<sum3_3.sum()<<endl;
	return 0;
}

 

#include<iostream>
using namespace std;
template<typename T>
class Add_3
{
public:
	Add_3(T a,T b,T c);
	T sum();
private:
	T x,y,z;
};
template<typename T>
Add_3<T>::Add_3(T a,T b, T c)
{x=a;y=b;z=c;}
template<typename T>
T Add_3<T>::sum()
{return x+y+z;}
int main()
{
    Add_3<int>sum3_1(1,4,7);
	Add_3<float>sum3_2(2.0,3.5,5.3);
	Add_3<double>sum3_3(40.5,5.4,6.1);
	cout<<"三个整数之和是:"<<sum3_1.sum()<<endl;
	cout<<"三个单精度数之和是:"<<sum3_2.sum()<<endl;
	cout<<"三个双精度数之和是:"<<sum3_3.sum()<<endl;
	return 0;