On Friday, 22 February 2013 at 15:15:02 UTC, kenji hara wrote:

2013/2/23 deadalnix <deadalnix@gmail.com>

class A {
    void foo() {}
}

class B {
    override void foo() const {}
}

Add a const foo method to A, and B;foo don't overload the same method
anymore.

B.foo overrides A.foo. It is properly allowed as a particular case in
contravariant parameter type.

Kenji Hara

I know that. Now if you add a const version of foo in A, B;foo don't override the same method anymore.