[boost] Re: Re: Re: Formal review or Variant Library (Ed B.)

From: Fernando Cacciola (fernando_cacciola_at_[hidden])
Date: 2003-02-19 12:52:57

"David Abrahams" <dave_at_[hidden]> wrote in message
news:usmuk890r.fsf_at_boost-consulting.com...
> "Fernando Cacciola" <fernando_cacciola_at_[hidden]> writes:
>
> >  Any idea about what to do with reference to reference problem?
>
> What's the problem?
>
Currently, optional<Y> has:

    explicit optional ( T const& val )
    T*       get();
    T*       operator->() ;
    T&       operator *();

those are all illegal if T is a reference type.

> >
> > What was the idea of:  optional< exactly<T&> > ?
>
> It's an ambiguity breaker: a way of specifying, when constructed with
> a variant<T,T&>, that you want to get the T& and not the T.
>
hmmm, shouldn't 'exactly' appear along with extract then?
What's the meaning of "optional< exactly<T&> > " by itself, without
variant<T,T&> in the scene?

--
Fernando Cacciola