/*******************类模板从类模板派生**********/

#include <iostream>
using namespace std;

template <class T1,class T2>
class A{
    T1 v1;
    T2 v2;
public:
    A(){cout<<"A!"<<endl;}
};

template <class T1,class  T2>
class B:public A<T2,T1>{
    T1 v3;T2 v4;
public:B(){cout<<"B!"<<endl;}
};

template <class T>
class  C:public B<T,T>{
    T v5;
public: C(){cout<<"C!"<<endl;}
};
int main()
{
    B<int,double >obj1;
    C<int> obj2;
    return 0;
}

//类模板由模板类派生
#include <iostream>
using namespace std;

template <class T1,class T2>
class A{
    T1 v1;
    T2 v2;
public:
    A(){cout<<"A!"<<endl;}
};
template <class T>
class B:public A<int,double >{ // A<int,double >是模板类
    T v;
public:
    B(){cout<<"B!"<<endl;}
};
int main()
{
    B<char> obj1;
    return 0;
}

#include <iostream>
using namespace std;
 class A{
     int v1;
 public:
     A(){cout<<"A!"<<endl;}
 };
 template <class T>
 class B:public A{//所以从B实例化的类都以A为基类
     T v;
 public:
     B(){cout<<"B!"<<endl;}
 };

 int main()
 {
     B<char> obj1;
     return 0;
 }

//普通类从模板类派生
#include <iostream>
using namespace std;
 template <class T>
 class A{
     T v1;
     int n;
 public:
     A(){cout<<"A!"<<endl;}
 };
 class B:public A<int> {
     double v;
 public:
     B(){cout<<"B!"<<endl;}
 };
 int main()
 {
     B obj1;
     return 0;
 }