Subject: Re: [boost] [type_traits] Rewrite and dependency free version
From: Peter Dimov (lists_at_[hidden])
Date: 2015-01-15 12:55:51
Agustín K-ballo Bergé wrote:
> On 1/15/2015 11:34 AM, Peter Dimov wrote:
> > Ion Gaztañaga wrote:
> >> In any case with my alternative implementation you could avoid even
> >> Boost.PP for manteinance and avoid all those overloads.
> > My first thought when looking at is_function was also to suggest
> > "is_convertible<T&,T*>", but then I saw that Ion has already got to it
> > first, complete with the nullptr_t check.
> This doesn't quite work as `void() const`, and any other combination of cv
> and ref qualifiers, is a function type but cannot be instantiated.
You're right. The current PP-based implementation doesn't catch those
either, though. Fortunately, if a compiler supports 'void () const &&', it
probably has std::is_function as well, so we can just use that. :-)
Although, now that I think of it, creating 'void() const' is in principle
possible in C++03 as well. Not sure what the old type traits did with such
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