Re: [boost] [result_of] fails with clan (C++11)

Subject: Re: [boost] [result_of] fails with clan (C++11)
From: Peter Dimov (lists_at_[hidden])
Date: 2012-11-27 16:28:39

Mathias Gaunard wrote:
> On 27/11/12 21:56, Jeffrey Lee Hellrung, Jr. wrote:
> > On Tue, Nov 27, 2012 at 12:47 PM, Oliver Kowalke
> > <oliver.kowalke_at_[hidden]>wrote:
> >
> >> Hello,
> >> clang (c++11 support) fails on code like:
> >>
> >> BOOST_STATIC_ASSERT((
> >>              is_same< void, typename result_of< Fn() >::type 
> >>  >::value));
> >>
> >> with error:
> >>
> >>   no type named 'type' in 'boost::result_of<void (&())(X &)>'
> >>              is_same< void, typename result_of< Fn() >::type 
> >>  >::value));
> >>                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~**~~
> >>
> >
> > Does Fn == void (&)(X&) or void (X&) ? I.e., is it a unary function 
> > type?
> >
> > There might've been a recent change only for Clang to allow result_of to 
> > be
> > better usable with SFINAE: result_of< F ( Args... ) > doesn't have a 
> > nested
> > type typedef if F ( Args... ) is ill-formed (which appears to be the 
> > case
> > here).
>
> And the person who did that change didn't think of running the test?

The test looks broken. A function that takes X& can't be called with zero 
arguments.