Re: [boost] Windows XP support survey

Subject: Re: [boost] Windows XP support survey
From: Matt Calabrese (rivorus_at_[hidden])
Date: 2015-05-07 22:27:10

On Thu, May 7, 2015 at 5:40 PM, Niall Douglas <s_sourceforge_at_[hidden]>
wrote:
>
> I'd have thought replacing the preprocessor probably just about the
> easiest compiler mod possible. We can even do it ourselves by getting
> winclang to feed preprocessed output to MSVC for us!
>

That's why I said "for other reasons." It'd be simple to just swap out the
preprocessor with a compliant one, but that breaks tons of code including
code in windows headers. Even the clang-cl effort tries to mimic funky MSVC
preprocessor behavior such that it is feasible to use in a windows system.
I'm pretty sure that in the past Microsoft has explicitly stated that they
have absolutely no plans of ever fixing their preprocessor, but I remain
hopeful that it will be fixed eventually.Unfortunately it tends to only be
people like boost developers who really care, and Boost.Preprocessor bends
over backwards to support MSVC anyway, so there's not enough incentive for
Microsoft to do anything.

> Two phase lookup, on the other hand, is likely to be one of the very
> hardest to support for a compiler like MSVC. I can see Concepts in
> MSVC before two phase lookup.

Oh yeah, definitely. If you're talking concepts-lite kind of concepts,
that's not much more complicated than C++11 SFINAE. I wouldn't be surprised
if that's one reason they actually are tackling SFINAE now.

-- 
-Matt Calabrese