Re: [boost] rvalue ref best practices?

Subject: Re: [boost] rvalue ref best practices?
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-06-16 00:24:10

on Fri Jun 15 2012, Mathias Gaunard <mathias.gaunard-AT-ens-lyon.org> wrote:

> On 15/06/2012 17:59, Dave Abrahams wrote:
>
>> 1. How can you tell whether bar failed or the assignment failed, here?
>
> If I know that T::operator= has the strong guarantee, 

Big if.  That wasn't part of the scenario you framed.

> I know that foo will always be in either of two states: either bar()
> succeeds, and it has the new value returned by bar(), or it failed,
> and it has the old value.

Yes, by definition.

> If overloading were allowed to take foo, half-modify it, then fail,
> then that wouldn't be true anymore.
>
>> 2. Do you really write code like that?
>
> Of course, what would be the point of exceptions is not to catch them?

Usually you want to do something with the exception once caught; your
code doesn't do that.  And code where the catch block doesn't rethrow
tends to be incredibly rare.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com