220 8339 <52C4908B.2030606@gmail.com> article
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From: Matthew Woehlke <mwoehlke.floss@gmail.com>
Newsgroups: gmane.comp.lang.c++.isocpp.proposals
Subject: Re: Proposal: Default swap operation
Date: Wed, 01 Jan 2014 17:02:51 -0500
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On 2014-01-01 16:48, Ville Voutilainen wrote:
> On 1 January 2014 23:29, Matthew Woehlke <mwoehlke.floss@gmail.com> wrote:
>> On 2014-01-01 14:53, Ville Voutilainen wrote:
>>> I don't see any wording in the standard that would require other TUs to
>>> see the =default to use the function.
>>
>>
>> I'm inclined to agree. I didn't consult the spec, but when I tried using it
>> in a project, I am not seeing link errors that I would expect if the
>> definition wasn't available to other TU's. (And I *do* see link errors if I
>> omit the dtor definition entirely, so the dtor is definitely being
>> referenced.)
>>
>> I'd also be curious about your reading of the spec. It may be that
>> technically such a program is ill-formed, but existing compilers (or at
>> least gcc) "DTRT" (i.e. behave in the desired manner) anyway?
>
>
> I have no reason to believe a program that defaults a special member
> after the first declaration is in any way ill-formed, quite the contrary.
> And I have no reason to believe such a definition wouldn't be accessible
> to other TUs. Both of these statements are based on my reading of the
> spec, it specifically allows defaulting after first declaration, and there's
> nothing saying such a definition is in any way static.

Right. Thiago, do we convince you? If not, would you kindly explain your 
take? (And/or does anyone know of any compilers that don't behave this way?)

Thanks,

-- 
Matthew

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