模板专业化和模板偏特样片(template specialization and partial template specialization)

/********************************************************************************* 
 Copyright (C), 1988-1999, drvivermonkey. Co., Ltd. 
 File name:  
 Author: Driver Monkey 
 Version:  
 Mail:bookworepeng@hotmail.com 
 Date: 2014.04.02 
 Description:  
 *********************************************************************************/ 
#include<stdlib.h>
#include <iostream>
#include <typeinfo>
#include <typeindex> 
#include <map>

using namespace std;

class A
{
    public:
    A(){cout<<"A created!"<<endl;}
};
struct SUB_A:public A
{
    public:
    SUB_A(){cout<<"SUB_A created!"<<endl;}
};

template<class T1, class T2> class CompileTimeChecker 
{ 
    public:
    T1 t1;
    T1 t2;
    CompileTimeChecker()
    {
        cout<<"1---CompileTimeChecker = "<<typeid(t1).name()<<endl; 
        cout<<"1---CompileTimeChecker = "<<typeid(t2).name()<<endl; 
    }
}; 

template <class T> class CompileTimeChecker<T,float>
{
    public:
        T t;
        CompileTimeChecker()
        {
            cout<<"2---CompileTimeChecker = "<<typeid(t).name()<<endl;
        }
};

template<> class CompileTimeChecker<A, SUB_A>
{ 
    public:
     A a;
     SUB_A sub_a;
    CompileTimeChecker()
    {
        cout<<"3---CompileTimeChecker = "<<typeid(a).name()<<endl; 
    }
   
}; 

int main(void)
{
    CompileTimeChecker<int, float> int_instance;
    CompileTimeChecker<int, int> a_instance;
    CompileTimeChecker<A,SUB_A> sub_instance;
}