How to specify a concept that requires a const method?

[JUANDENT]

Hi,

I have this:

class Circle : public GeoObj {
public:
    virtual void draw() const override;
};

So I have created a concept like this:

    template<typename T>
    concept GeoObject = requires(const T & x) {
        { x.draw() } -> std::convertible_to<void>;
    };

I require draw() to be a const method. Does this concept GeoObject ensure this is the case?

If not how can I change the concept in order that it enforces constness?

[mbozzi]

Yes, because it checks for x.draw() where x has type T const.

I think every type is convertible to void.

[JUANDENT]

yes you are correct about every type being convertible to void!

Thanks!