模板类与继承

1模板类继承普通类（常见）

#include<iostream>
using namespace std;
class AA
{
public:int m_a;AA(int a) :m_a(a) { cout << "调用了AA的构造函数\n"; }void func1() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
template <class T1,class T2>
class BB
{
public:T1 m_x;T2 m_y;BB(const T1 x, const T2 y) :m_x(x), m_y(y) { cout << "调用了BB的构造函数，\n"; }void func2() { cout << "调用了func2（）函数：x = " << m_x << "y = "<<m_y<<endl; ; }
};
int main() {BB<int, string> bb(8, "zhongge");bb.func2();return 0;
}

现在AA BB没有任何关系，如果把普通类作为基类，把模板类BB作为子类，继承AA。

#include<iostream>
using namespace std;\
class AA
{
public:int m_a;AA(int a) :m_a(a) { cout << "调用了AA的构造函数\n"; }void func1() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
template <class T1,class T2>
class BB:public AA
{
public:T1 m_x;T2 m_y;BB(const T1 x, const T2 y) :m_x(x), m_y(y) { cout << "调用了BB的构造函数，\n"; }void func2() { cout << "调用了func2（）函数：x = " << m_x << "y = "<<m_y<<endl; ; }
};
int main() {BB<int, string> bb(8, "zhongge");bb.func2();return 0;
}

让BB继承AA但是出现了错误：AA没有合适的默认的构造函数。

继承的时候派。生类如何构造基类：要在派生类BB构造函数的初始化列表中指明基类的构造函数。

#include<iostream>
using namespace std;\
class AA
{
public:int m_a;AA(int a) :m_a(a) { cout << "调用了AA的构造函数\n"; }void func1() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
template <class T1,class T2>
class BB:public AA
{
public:T1 m_x;T2 m_y;BB(const T1 x, const T2 y,int a) :AA(a),m_x(x), m_y(y) { cout << "调用了BB的构造函数，\n"; }void func2() { cout << "调用了func2（）函数：x = " << m_x << " ,y = "<<m_y<<endl; ; }
};
int main() {BB<int,string> bb(8, "zhongge",3);bb.func2();bb.func1();return 0;
}

调用了AA的构造函数
调用了BB的构造函数，
调用了func2（）函数：x = 8 ,y = zhongge
调用func1（）函数 ：m_a = 3C:\Users\代伟业\Desktop\C++\初始化列表\ConsoleApplication1\x64\Debug\ConsoleApplication1.exe (进程 19556)已退出，代码为 0。
按任意键关闭此窗口. . .

2普通类继承模板类的实例版本

#include<iostream>
using namespace std;
template <class T1, class T2>
class BB
{
public:T1 m_x;T2 m_y;BB(const T1 x, const T2 y) : m_x(x), m_y(y) { cout << "调用了BB的构造函数，\n"; }void func2() { cout << "调用了func2（）函数：x = " << m_x << " ,y = " << m_y << endl; ; }
};class AA :public BB <int,string>
{
public:int m_a;AA(int a,int x,string y) :BB(x,y),m_a(a) { cout << "调用了AA的构造函数\n"; }void func1() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
int main() {AA aa(3,8,"zhongge");aa.func2();aa.func1();return 0;
}

调用了BB的构造函数，
调用了AA的构造函数
调用了func2（）函数：x = 8 ,y = zhongge
调用func1（）函数 ：m_a = 3C:\Users\代伟业\Desktop\C++\初始化列表\ConsoleApplication1\x64\Debug\ConsoleApplication1.exe (进程 7360)已退出，代码为 0。
按任意键关闭此窗口. . .

3普通类继承模板类

#include<iostream>
using namespace std;
template <class T1, class T2>
class BB
{
public:T1 m_x;T2 m_y;BB(const T1 x, const T2 y) : m_x(x), m_y(y) { cout << "调用了BB的构造函数，\n"; }void func2() { cout << "调用了func2（）函数：x = " << m_x << " ,y = " << m_y << endl; ; }
};
template <class T1, class T2>
class AA :public BB <T1,T2>
{
public:int m_a;AA(int a,T1 x,T2 y) :BB<T1,T2>(x,y),m_a(a) { cout << "调用了AA的构造函数\n"; }void func1() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
int main() {AA<int,string> aa(3,8,"zhongge");aa.func2();aa.func1();return 0;
}

4模板类继承模板类。

#include<iostream>
using namespace std;
template <class T1, class T2>
class BB
{
public:T1 m_x;T2 m_y;BB(const T1 x, const T2 y) : m_x(x), m_y(y) { cout << "调用了BB的构造函数，\n"; }void func2() { cout << "调用了func2（）函数：x = " << m_x << " ,y = " << m_y << endl; ; }
};
template <class T1, class T2>
class AA :public BB <T1,T2>
{
public:int m_a;AA(int a,T1 x,T2 y) :BB<T1,T2>(x,y),m_a(a) { cout << "调用了AA的构造函数\n"; }void func1() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
template <class T,class T1,class T2>
class CC:public BB<T1,T2>
{public:T m_a;CC(const T a, const T1 x,const T2 y) :BB<T1, T2>(x, y), m_a(a) { cout << "调用leCC的构造函数\n"; }void func3() { cout << "调用func1（）函数 ：m_a = " << m_a << endl; }
};
int main() {AA<int,string> aa(3,8,"zhongge");aa.func2();aa.func1();CC <int,int,string> cc(3, 8, "我是一只傻傻鸟");return 0;
}

5模板类继承模板参数给出的基类（不能是模板类）

#include<iostream>
using namespace std;class AA
{
public:AA(){ cout << "调用leAA的构造函数\n"; }AA(int a) { cout << "调用leAA(int a)的构造函数"; }
};
class BB
{
public:BB() { cout << "调用leBB的构造函数\n"; }BB(int a) { cout << "调用leBB(int a)的构造函数"; }
};
template <class T>
class CC:public T
{public:CC():T() { cout << "调用leCC的构造函数\n"; }CC(int a):T(a) { cout << "调用leCC(int a)的构造函数"; }
};int main() {CC<AA> ca1;//AA作为基类CC<BB> cb2;//BB作为基类return 0;
}