c++ - 接口(interface)C++的好处？

Question

看这段代码

#include<iostream>

using namespace std;

    //Shape is an Interface Class. No data and everything pure virtual
    class Shape {
    public:
      virtual void Area(int length, int breadth) = 0;
      virtual void Perimeter(int length, int breadth) = 0;
      //Note, no data
    };

    //Derived class - Inherits Shape as Public
    class Rectangle : public Shape {
    public:
      void Area(int length, int breadth);
      void Perimeter(int length, int breadth);
    private:
      int someData;
    };

    //Derived class - Inherits Shape as Public
    class Triangle : public Shape {
    public:
      void Area(int length, int breadth);
      void Perimeter(int length, int breadth);
    private:
      int someData;
    };

    int main()
    {
      Rectangle r;
      Triangle t;

      cout<<"\n\n";
      r.Area(3,4);
      r.Perimeter(3,4);

      t.Area(3,4);
      t.Perimeter(3,4);

      cout<<"\n\n";
      return 0;
    }

    void Rectangle::Area(int length, int breadth)
    {
      cout<<"\nThe Area of Rectangle for length = "<<length<<" and\
      breadth = "<<breadth<<" is "<<(length * breadth)<<endl;
    }

    void Rectangle::Perimeter(int length, int breadth)
    {
      cout<<"\nThe Perimeter of Rectangle for length = "<<length<<" and\
      breadth = "<<breadth<<" is "<<2 * (length + breadth)<<endl;
    }

    void Triangle::Area(int length, int breadth)
    {
      cout<<"\nThe Area of Triangle for length = "<<length<<" and\
      breadth = "<<breadth<<" is "<<(length * breadth)/2<<endl;
    }

    void Triangle::Perimeter(int length, int breadth)
    {
      cout<<"\nThe Perimeter of Triangle for length = "<<length<<" and\
      breadth = "<<breadth<<" is "<<(length * breadth)/3<<endl;
    }

我在代码中使用接口(interface)，但我的问题是我应该使用它做什么以及它有什么好处，没有性能，没有真正需要它，为什么我应该使用它(接口(interface))。使用它有什么意义，请您解释一下。

谢谢!

Answer 1

抽象接口(interface)将接口(interface)与实现分开。就像pimpl的成语一样

• 减少编译时间，并且
• 让您可以在不破坏 ABI 的情况下更改实现。

两者在大型程序中都是重要的优势。