Re: [boost] [clang] How to use CLang for Windows?

Subject: Re: [boost] [clang] How to use CLang for Windows?
From: Edward Diener (eldiener_at_[hidden])
Date: 2013-09-29 22:07:24

On 9/29/2013 9:13 PM, Beman Dawes wrote:
> On Sun, Sep 29, 2013 at 8:36 PM, Edward Diener <eldiener_at_[hidden]>wrote:
>
>>
>> There are other cases in the Boost header files that assume that when
>> _MSC_VER is defined the compiler is VC++ ( see my thread "Boost and clang
>> under Windows" ) without checking if it could be another compiler emulating
>> VC++.
>
>
> But that is a mistake. BOOST_MSVC has been the preferred macro to check for
> VC++ since September of 2001. Since even before then there have been
> non-Microsoft compilers that define _MSC_VER.

The Boost PP config.h file was created by Paul Mensonides. Boost PP does 
not use the Boost.Config library or any other Boost library, so using 
BOOST_MSVC is not possible. You need to talk to Paul about his reasons 
and design. I am just trying to "fix" the Boost PP library so that clang 
on Windows works there.

The reality is that a number of other Boost libraries use _MSC_VER 
instead of BOOST_MSVC in order to check for VC++ emulation. In some of 
those other libraries further checks are done to detect which actual 
compiler is using _MSC_VER and different code is often invoked in that 
case. But naturally there are no further checks for clang, since clang 
under Windows with _MSC_VER defined is "new".