Re: [boost] [Boost.Move] A few notes

Subject: Re: [boost] [Boost.Move] A few notes
From: Dan Ivy (danivy.mail_at_[hidden])
Date: 2012-01-12 10:01:35

On Thu, Jan 12, 2012 at 2:50 PM, Thomas Klimpel
<Thomas.Klimpel_at_[hidden]> wrote:
> Dan Ivy wrote:
>> Ultimately, this is what I suggest:
>> First of all, have boost::move accept temporaries. Secondly, seriously
>> consider changing the definition of BOOST_FWD_REF(T) from const T& to
>> T&, as this would acheive two desirable, IMO, goals::
>> a. Forwarding functions would accept modifiable lvalues (and keep them
>> modifiable).
>> b. Forwarding functions would REJECT temporaries, UNLESS they're passed
>> through boost::move, which assures that they're treated as rvalues.
>
> Especially your point "a" reveals a different understanding of "boost::forward" and "BOOST_FWD_REF" than I gained during the review. My understanding was that the sole purpose of "boost::forward" and "BOOST_FWD_REF" is to enable "Constructor Forwarding" (see <http://www.boost.org/doc/libs/1_48_0/doc/html/move/construct_forwarding.html>). So the purpose of "boost::forward" is not to emulate "std::forward" for more general use cases.

I don't see it. How is "constructor forwarding" any different than
"more general forwarding" in that respect, or, in any other respect?