c++ 类模板编程

1.头文件

//单参数类模板

#ifndef  _OPERATOR_H
#define _OPERATOR_H

#include<iostream>
using namespace std;
//单个参数函数模板
template < typename T >
class Operator
{
public:
    T add(T a, T b);
    T minus(T a, T b);
    T multiply(T a, T b);
    T divide(T a, T b);
};
//多个参数函数模板
template < typename T1,typename T2 >
class Operator_1
{
public:
    void add(T1 a, T2 b);
};

//类模板特化-完全特化
template <>                           
class Operator_1< int , int>          
{                                               
public:
void add(int a, int b)
{
cout<<a+b<<endl;
}

};
//部分特化，当两个参数都是指针调用该参数
template < typename T1,typename T2 >  
class Operator_1<T1*,T2*>                                   //部分特化的类模板,当两个参数都是指针,调用这个
{
public:
        void add(T1* a, T2* b)
       {
              cout<<"add(T1* a, T2* b)"<<endl;
              cout<<*a+*b<<endl;
       }
};


template < >  
class Operator_1<void*,void*>                             //完全特化的类模板,当两个参数都是void*,调用这个
{
public:
        void add(void* a, void* b)
       {
              cout<<"add(void* a, void* b)"<<endl;
              cout<<"add void* Error"<<endl;                 //void*无法进行加法
       }
};



template < typename T >           //外部定义的成员函数,都需要加上模板声明
T  Operator<T> :: add(T a, T b)   //同时加上结构体<T>声明
{
       return a+b;
}

template < typename T >          
T  Operator<T> :: minus(T a, T b)
{
       return a-b;
}
template < typename T >          
T  Operator<T> :: multiply(T a, T b)
{
       return a*b;
}

template < typename T >          
T  Operator<T> :: divide(T a, T b)
{
       return a/b;
}



template < typename T1,typename T2 >
void Operator_1<T1,T2 > :: add(T1 a, T2 b)
{
        cout<<a+b<<endl;
}



#endif

2.cpp文件

#include<string>
#include"Operator.h"

using namespace std;


string operator-(string &l,string r)
{
    return "minus";
}

int main()
{
 Operator<int> op1;
 op1.add(1,2);
 cout<<op1.add(1,2)<<endl;

 Operator_1 <int ,float>op2;
 op2.add(1,2);

 Operator_1<int,int>op3;
 op3.add(1000,2000);

 int *p1 = new int(1);
 float *p2 = new float(1.25);

 Operator_1<int*,float*>  Op4;      //匹配部分特化的类模板:class Operator<T1*,T2*>      
 Op4.add(p1,p2);

 Operator_1<void*,void*>  Op5;      //匹配完全特化的类模板:class Operator<void*,void*>
 Op5.add(NULL,NULL);  

 delete p1;
 delete p2;

 return 0;
}