Re: [boost] [proto] small breaking change

Subject: Re: [boost] [proto] small breaking change
From: Eric Niebler (eric_at_[hidden])
Date: 2010-06-14 09:18:26

On 6/14/2010 2:10 AM, joel falcou wrote:
> Eric Niebler wrote:
>> Heck, it's simple enough. I just checked in the fix on trunk. Let me
>> know how that works for you.
>>   
> OK the base case is working now. I just got a last small problem.
> 
> If I try to evaluate :
> 
>  m = l+k,
>  x = x + y;

I suspect that this is due to a recent change in as_child/as_expr. They
used to return references even when they clamed (via result_of) to
return values. This was to elide unnecessary copies. But this doesn't
work in a world where decltype and auto exist and can independently
compute the actual return type of a function. I had thought RVO would
eliminate the copies for me, but I must be doing it wrong. I'll try to
put it back like it was before until I can't figure it out.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com