Problems with D const ref vs C++ const &

[Piotr Szturmaj]

Craig Black wrote:
> In C++ I could to the following:
>
> Vector3 cross(const Vector3 &a, const Vector3 &b) { ... }
>
> and then call it like this:
>
> Vector3 a, b, c;
> a = cross(b, c);
> a = cross(b-a, c-a);
>
> But in D I have to define two functions if I want pass by reference to
> work:
>
> Vector3 cross(ref const Vector3 a, ref const Vector3 b) {...}
> Vector3 cross(Vector3 a, Vector3 b) {...}

Isn't const for that (without ref)?

Vector3 cross(const Vector3 a, const Vector3 b) {...}

In this case, compiler should pass const by reference (since it will not 
change).