CODEWITHSUNDEEP
c++
Jake Freelander
Jake Freelander

Reputation: 1471

Overload return types?

Lets say i have a class

Class rofl {
 int a;
 float b;
 rofl::rofl(int a, float b) {
  this->a = a; this->b = b;
 }
}

is it possible to do

rofl* sup = new rofl(5, 2.0f);
float hello = sup;

so that variable hello would get the value of sup.b?

Upvotes: 1

Views: 117

Answers (3)

Komi Golov
Komi Golov

Reputation: 3471

No, in the case that you stated this is not possible. In your code, sup is not a rofl but a rofl*, and creating a rofl* to float conversion is not allowed. Moreover, your question is ill-formed: sup.b does not refer to anything.

That said, you probably don't need to dynamically allocate the instance, in which case the other answers are correct.

Upvotes: 1

Oliver Charlesworth
Oliver Charlesworth

Reputation: 272467

Yes, you can overload type-conversion operators:

class Rofl {
public:
    operator float() const { return b; }

    ...
};

See http://ideone.com/Y7UwV for a demo.

However, see Item 5 of Scott Meyers' More Effective C++, entitled "Be wary of user-defined conversion operations". Allowing implicit conversions to-and-from complex types can often lead to all sorts of subtle typo bugs.

Upvotes: 8

Eric
Eric

Reputation: 97565

You can also go the other way around:

class rofl {
public:
    float operator=(float f) { b = f; return f; }

    ...
};

rofl sup(5, 2.0f);
sup = 4.0f;

demo, based on @Oli's answer

Upvotes: 1

Related Questions