Re: [boost] Re: Perfect moving (almost)

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-02-11 13:03:44

David Abrahams wrote:
> "Peter Dimov" <pdimov_at_[hidden]> writes:
>
>> David Abrahams wrote:
>>> "Peter Dimov" <pdimov_at_[hidden]> writes:
>>>
>>>> The compiler is allowed to elide a temporary created by a copy
>>>> constructor.
>>>>
>>>> The compiler is _not_ allowed to elide a temporary created by some
>>>> other constructor, because this changes observable behavior and is
>>>> not explicitly allowed.
>>>
>>> I think what's explicitly allowed depends on your reading of 8.5.3/5
>>
>> No, the relevant portion here is 12.8/15.
>
> 1. Do you realize that 12.8/15 was almost completely rewritten by
>    Core issue 20?

No, I did not, thanks for the pointer. No relevant changes, though. Only
copy constructors can be optimized out.

> 2. I still think it's arguable that 8.5.3/5 does not require a copy
>    constructor to be used in my example, making 12.8/15 irrelevant
>    AFAICT.

Well, I suppose that you could argue that if you like, but does it help your
cause? ;-)