non-const reference to const instance of class

[Zhenya]

On Wednesday, 10 October 2012 at 17:35:48 UTC, Jonathan M Davis 
wrote:
> On Wednesday, October 10, 2012 19:02:31 Zhenya wrote:
>> Hi!
>> 
>> I thought that this should compile:
>> class Foo{}
>> 
>> const(Foo) foo = new Foo;// the same that const Foo foo?
>> foo = new Foo;
>> 
>> but compiler say that foo is const reference and it can't 
>> modify
>> it.
>> It is normally?If yes,how can I declare non-const reference to
>> const instance of class?
>
> const Foo and const(Foo) are the same thing. They both create a 
> const
> reference to const data. This is in contrast to a pointer where 
> const Bar* and
> const(Bar)* are different. With a reference, there is no way to 
> indicate that
> the object is const but not the reference. The type system just 
> doesn't
> support the idea of a class object existing separately from a 
> reference, so
> there's no way to make that distinction.
>
> If you want to have a mutable reference to a const object, then 
> you need a
> wrapper around the reference where the wrapper is mutable but 
> the reference
> isn't. std.typecons.Rebindable does this. It's what you should 
> use.
>
> - Jonathan M Davis

Thank you)