Re: [boost] decltype and incomplete types

Subject: Re: [boost] decltype and incomplete types
From: Eric Niebler (eric_at_[hidden])
Date: 2010-04-09 16:09:59

On 4/8/2010 1:53 PM, Daniel Walker wrote:
> On Thu, Apr 8, 2010 at 2:18 PM, Eric Niebler <eric_at_[hidden]> wrote:
>>
>> 7.1.6.2/4:
>> "The type denoted by decltype(e) is defined as follows:
>> — if e is ... or if e names a set of overloaded functions, the program is
>> ill-formed;"
>>
<snip>
> 
> If overload resolution succeeds then e names a statically chosen
> function not an overload set. If overload resolution fails then e
> names an overload set and the program is ill-formed. That's my
> understanding at least. So, yes, you can use decltype on an overloaded
> function and the program is not ill-formed, so long as overload
> resolution succeeds. I believe that's true of call expressions in any
> context.

Daniel, you're probably right. Thanks for the clarification. I think
Steven is right though that if you use an incomplete type in a function
call expression (a possibly overloaded function set), then the program
is ill-formed if any signature in the function set requires a complete
type. This can happen in any context, decltype or not, so I don't think
it has bearing on this discussion.

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