Re: [boost] enabling constexpr with Visual studio 2015 Update 3 (RC)

Subject: Re: [boost] enabling constexpr with Visual studio 2015 Update 3 (RC)
From: Paul A. Bristow (pbristow_at_[hidden])
Date: 2016-06-15 04:40:40

> -----Original Message-----
> From: Boost [mailto:boost-bounces_at_[hidden]] On Behalf Of Paul A. Bristow
> Sent: 13 June 2016 14:55
> To: boost_at_[hidden]
> Subject: Re: [boost] enabling constexpr with Visual studio 2015 Update 3 (RC)
> > -----Original Message-----
> > From: Boost [mailto:boost-bounces_at_[hidden]] On Behalf Of Beman Dawes
> > Sent: 11 June 2016 17:06
> > To: Boost Developers List
> > Subject: Re: [boost] enabling constexpr with Visual studio 2015 Update 3 (RC)
> >
> > On Sat, Jun 11, 2016 at 11:57 AM, Glen Fernandes <glen.fernandes_at_[hidden]>
> > wrote:
> >
> > > On Sat, Jun 11, 2016 at 11:41 AM, Paul A. Bristow  wrote:
> > > In develop, you have the option of defining BOOST_MSVC_CXX11_CONSTEXPR.
> > >
> >
> > +1.
> >
> > You might want to read the thread "[config] Changes needed for VC++ 2015
> > Update 3?" if you have not already done so.

> https://groups.google.com/forum/#!topic/boost-developers-archive/yzERahUyJRE

> > Please file a MSVC bug report if you hit any C++11 constexpr bugs in the
> > Update 3 RC. They giving very high priority to C++11 bugs affecting Boost
> > code. They would like us to be able to turn BOOST_NO_CXX11_CONSTEXPR off
> > for Update 3.
> 
> I've re-re-read the above and realized that I had assumed (the mother of all snafus) C++14 not C++11

BOOST_MSVC_CXX14_CONSTEXPR

which has no effect,  but BOOST_MSVC_CXX11_CONSTEXPR

works as expected (though the compiler is little help in telling just where the constexpr chain is broken :-).

But IMO *we really must know* which of std:c++14 and std::c++lastest  (and others including c++11, c++17) are being specified for
the compiler to use.

The compiler version _MSC_FULL_VER = 190024123 does not tell you this - only that it is VS 2015 update 3.

I agree that this is a showstopper for Boost.  Has this message got back to Microsoft?

Paul

---
Paul A. Bristow
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