Re: firefox still fails on 2020Q1, netbsd-8, amd64

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Mon, May 11, 2020 at 11:38:47AM +0100, Mike Pumford wrote:
> 
> 
> On 10/05/2020 17:35, nia wrote:
> > On Sun, May 10, 2020 at 05:20:40PM +0100, Chavdar Ivanov wrote:
> > > fatal error: 'cstddef' file not found
> > 
> > Yeah, this is the bug caused by the incorrect logic in lang/clang.
> > 
> > It's why I took longer than usual to commit a firefox-esr update.
> > 
> > Should be fixed by updating lang/clang.
> > 
> Even with that fix, 8-stable can't build firefox it blows up with:
> 
> In file included from
> /comp/obj/pkgsrc/www/firefox/work/build/dist/include/mozilla/UniquePtr.h:17:
> /comp/obj/pkgsrc/www/firefox/work/build/dist/include/mozilla/CompactPair.h:32:20:
> error: no template named 'is_empty_v' in namespace 'std'; did you mean
> 'is_empty'?
>               std::is_empty_v<A> ? detail::AsBase : detail::AsMember,
>               ~~~~~^~~~~~~~~~
> Amongst other errors all relating to similar type calls.
> 
> Sadly I think this is the fault of firefox. is_empty_v is not documented on
> the C++ reference site I normally use and I've never found anything else
> missing before. I use
> https://en.cppreference.com/w/cpp/types
> 
> There is a std:is_empty but not a std::is_empty_v so it looks like firefox
> is relying on some sort of non-standard extension or something so new that
> its not made it into documentation yet.

I think

template< class T >
inline constexpr bool is_empty_v = is_empty<T>::value;

but only since c++17


Cheers,

Patrick