auto return type inheritance not covariant

[bearophile]

iLewis:

> Maybe this has been brought up before, but i could find no previous submissions.

It looks like a bug fit for Bugzilla:

class Foo {
    int fun1() { return 1; }
    auto fun2() { return 1; }
    auto fun3() { return 1; }
}
class Bar : Foo {
    override auto fun1() { return 1; }
    override int fun2() { return 1; }
    override auto fun3() { return 1; }
}
void main() {}

Bye,
bearophile