[boost] Re: move semantics

From: David Abrahams (dave_at_[hidden])
Date: 2004-04-19 09:24:55

"Fredrik Blomqvist" <fredrik_blomqvist_at_[hidden]> writes:

> David Abrahams wrote:
>> Andrea Torsello <torsello_at_[hidden]> writes:
>>
> [snip]
>>> Yes, actually different compilers seem to act differently here.
>>> Since the compiler is free to copy const rvalues to non-const
>>> rvalues and optimize the copy away, I would consider returning a
>>> const temporary an odd thing to do. I am curious: does anyone have a
>>> use-case for it?
>>
>> I doubt it; it doesn't seem like a very important case.  It could be
>> used to have some effects on overload resolution I suppose, but it's
>> hard to imagine that being useful in real code.
>>
> Just a comment on the 'const temporary return' issue.
> I'd say it's not really an issue of whether it's useful per se, but how it
> is _actually used_ in real code as a "safety" feature.
> I.e to prevent: (a*b) = c;
> Scott Meyers' Effective C++, item 21, labels this "The Right Thing To Do".
> I've seen similar recommendations in a couple of coding-guidelines and
> several times in real code, most likely inspired by EC++ or similar.
> Thus it will appear in real code if nothing else for a matter of style.

Whoops; good point!

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com