C++ 抽象类

#include <iostream>

class AbstractBase{
public:
    explicit AbstractBase(int b): b_(b){}
    virtual int GetMember()=0;
    int b_;
};

class Derived: public AbstractBase{
public:
    explicit Derived(int d, int b): AbstractBase(b), d_(d){}
    int d_;
    virtual int GetMember() {return d_;}
};
int main()
{
	/*父类是抽象类，若父类中有纯虚函数时，子类必须重写，否则子类创建对象失败
	*/
    Derived d(2,3);
    return 0;
}

// 和上面等价，用到C++11中类成员就地初始化和继承构造
class AbstractBase{
public:
    explicit AbstractBase(int b): b_(b){}
    virtual int GetMember()=0;
    int b_;

};

class Derived: public AbstractBase{
public:
    int d_ = 2;
    virtual int GetMember() {return d_;}
    using AbstractBase::AbstractBase;
};
int main()
{
    Derived d(2);
    return 0;
}