CODEWITHSUNDEEP
c++inheritance
Hana
Hana

Reputation: 613

Derived operator< receiving Base object as parameter

I know that a derived class "is a" base class, therefore you can always pass a derived object to a base member function. Now, I was wondering about the reverse situation specifically with comparing operators (base class is not abstract and has objects).

Lets say I have:

class Base:
{
    public:
        Base(int m1, string m2);
        virtual ~Base();
        int GetM1()const;
        string GetM2()const;

        virtual bool operator<(const Base& base)const;

    private:
        int m1;
        string m2;
};

And I want to do something like this:

class Derived: public Base
{
    public:
    Derived(string member);
    ~Derived();

    virtual bool operator<(const Base& base)const; // is this possible(without cast)???

};

Thanks

Upvotes: 1

Views: 45

Answers (1)

Barmar
Barmar

Reputation: 780655

Yes, it's possible. The Derived opererator will be used in code like this:

Base b;
Derived d;
if (d < b) {
    ...
}

You could also have some other class derived from Base, such as Derived1, and it will be used:

Derived1 d1;
Derived d;
if (d < d1) {
    ...
}

Upvotes: 2

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