Re: [boost] Clang 4.0.0 MPL error in Boost next.hpp and prior.hpp

Subject: Re: [boost] Clang 4.0.0 MPL error in Boost next.hpp and prior.hpp
From: Peter Dimov (lists_at_[hidden])
Date: 2017-03-26 15:28:34

Edward Diener wrote:
On 3/26/2017 7:59 AM, Peter Dimov via Boost wrote:
>
> > TL;DR as I said yesterday, you need to to the changes unconditionally 
> > for __clang__ and not look at __GNUC__.
>
> I do not understand this. You are saying that __clang__ being defined and 
> _MSC_VER being defined should always be strict compliance with variadics 
> turned on but without any VC++ related fixes ?

Yes.

Before the changes:

clang -fms-compatibility: broken
clang -fno-ms-compatibility: broken

After your changes (conditional upon __GNUC__):

clang -fms-compatibility: broken
clang -fno-ms-compatibility: working

After same changes, unconditional:

clang -fms-compatibility: working
clang -fno-ms-compatibility: working

> What about the so-called emulation by clang of the non-standard VC++ 
> preprocessor ?

There apparently exists no such emulation, at least as far as the PP tests 
show. Maybe it existed once, I don't know, but this doesn't seem to be the 
case today.