From: David Abrahams (dave_at_[hidden])
Date: 2003-02-19 13:37:50
"Fernando Cacciola" <fernando_cacciola_at_[hidden]> writes:
> "David Abrahams" <dave_at_[hidden]> wrote in message
>> "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.
explicit optional ( typename add_reference<typename add_const<T>::type>::type val )
typename add_pointer<typename remove_reference<T>::type>::type get();
typename add_pointer<typename remove_reference<T>::type>::type operator->() ;
typename add_reference<T>::type operator *();
>> > 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?
I dunno, maybe nothing; we were talking about optional as a
replacement for extract.
-- Dave Abrahams Boost Consulting www.boost-consulting.com
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