模板类派生模板类

#include <iostream>
using namespace std;

template< typename T>
class A
{
public:
A(T a)
{
this->a = a;
}
void printA()
{
cout<< "a:"<<a<< endl;
}
protected:
private:
T a;
};
//模板派生是需要具体化模板类 c++编译器需要知道 父类的数据类型具体是什么样的(派生类首先调用父类的构造函数)
//=====》要知道父类所占内存大小是多少，只有数据类型固定下来，才知道如何分配内存
class B: public A< int>
{
public:
B():A( 1)
{
this->a = 10;
}
void printA()
{
cout<< "a:"<<a<< endl;
}
protected:
private:
int a;
};
//类模板派生类模板
template< typename T>
class B2: public A <T>
{
public:
B2(T c, T d):A <T> (c)
{
this->c = c;
this->d = d;

}
void printC()
{
cout<< "c:"<<c<< endl;
}
protected:
private:
T c;
T d;
};

//类模板做函数参数

void UseA(A<float> &a)
{
a.printA();
}

int main()
{

B2< int> b( 1, 2);
b.printC();

system( "pause");
return 0;
}