Re: cas and interfaces

[Rene Zwanenburg via Digitalmars-d-learn]

On Tuesday, 25 December 2018 at 22:07:07 UTC, Johannes Loher 
wrote:
Thanks a lot for the info, that clarifies things a bit. But it 
still leaves the question, why it works correctly when 
inheriting from an abstract class instead of implementing an 
interface... Any idea about why that?

Unlike interfaces, base class references don't need adjustment. 
You can see this in action by printing addresses:

https://run.dlang.io/is/m6icVr

import std.stdio;

interface I {}
class Base : I {}
class Derived : Base { }

void main()
{
    auto derived = new Derived;
    Base base = derived;
    I i = derived;

    writeln(cast(void*)derived);
    writeln(cast(void*)base);
    writeln(cast(void*)i);
}

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