Re: [boost] [optional] generates unnessesary code for trivial types

Subject: Re: [boost] [optional] generates unnessesary code for trivial types
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2012-02-09 12:54:42

On Thursday, February 09, 2012 15:33:03 Andrzej Krzemienski wrote:
> I believe that
> optional<reference_wrapper<T>> would serve your purpose best. Or would it
> also introduce the lack of uniformity?

One additional note on this. I would like optional<T&> to be perfectly 
implementable as a wrapper around T*. optional<reference_wrapper<T>> does not 
allow this, at least not with its generic interface, since optional<T>::get() 
returns T&, which effectively forces optional<reference_wrapper<T>> to store 
reference_wrapper internally (along with the value presence flag). 
Specializing optional on std::reference_wrapper does not solve the problem 
entirely because there is also boost::reference_wrapper. It would be odd if 
optional worked differently with different reference_wrappers.