Re: [boost] [move] explicit moving from a rvalue

Subject: Re: [boost] [move] explicit moving from a rvalue
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2012-03-27 11:05:32

On Mon, Mar 26, 2012 at 1:41 PM, Vicente J. Botet Escriba <
vicente.botet_at_[hidden]> wrote:

> Le 26/03/12 22:18, Ion Gaztañaga a écrit :
>
>> El 26/03/2012 22:15, Ion Gaztañaga escribió:
>>
>>> El 26/03/2012 21:42, Vicente J. Botet Escriba escribió:
>>>
>>>> Hi Ion,
>>>>
>>>> With the current emulation of move semantics of Boost.Thread using
>>>> Boost.move, I have a case that I would like to make working in a
>>>> portable way
>>>>
>>>> boost::thread t = boost::thread( MoveOnly());
>>>>
>>>> The library declares the template move constructor from a movable
>>>> callable as as follows
>>>>
>>>> template <class F>
>>>> explicit thread(boost::rv<F>& f);
>>>>
>>>
>>> Why is the constructor explicit?
>>>
>>
>> Sorry, I replied too fast, thinking it was a plain move constructor. I
>> see the need for it.
>>
>>  The problem is a know limitation as the compiler is unable to deduce F
>>> as been MoveOnly even if MoveOnly is convertible to boost::rv<MoveOnly>&
>>> Jeffrey Lee Hellrung, Jr. made a proposal to try to solve the issue, but
>>> his proposal has a performance penality.
>>>
>>
>> I just wonder if some kind of "always_inline" attribute for this proposal
>> would fix the performance issue.
>>
>>
>>  IIRC, the approach was based on type erasure, so I don't think that
> inlining will help. Jerry?
>

[I assume that's me.]

Perhaps. I can look into it once I get back from vacation. Ping me if you
don't hear anything about it in a couple weeks :)

- Jeff