Re: [boost] [config] Boost PP and variadic macros

Subject: Re: [boost] [config] Boost PP and variadic macros
From: Edward Diener (eldiener_at_[hidden])
Date: 2011-04-03 13:03:51

On 4/3/2011 12:46 PM, Chad Nelson wrote:
> On Sun, 03 Apr 2011 11:58:58 -0400
> Edward Diener<eldiener_at_[hidden]>  wrote:
>
>> [...] My initial thought was to see if config could work with C
>> compilers, but all investigation there has led me to believe that it
>> would be too many unnecessary changes to config, would complicate
>> config greatly, would need extensive testing against all compilers,
>> and that since config is central to all of Boost such a potential
>> massive change to it it is a bad idea. [...]
>
> What about simply wrapping everything in config, except the varadic
> stuff, in an "#ifdef __cplusplus"?

That was the original thought. But it would mean testing each 
compiler/version to make sure that __cplusplus was actually being set 
when compiling a C++ program.

> It would be an unobtrusive change,
> and that define is required by every C++ standard I've seen (note: I've
> only seen working drafts, not the final copies, though I don't expect
> that part has changed).

It might be unobtrusive but there are very many config header files in 
which one would have to do that. Even doing it just for each compiler's 
header file would mean that each compiler would have to be tested which 
config supports. I do not think we even have every compiler which config 
supports being tested regularly, but I may be wrong.

>
> I know that even Borland's compilers (arguably the most problematic
> ones in common use today) have defined that since Turbo C++ 1.0 in the
> eighties.

There are other compilers "supported" by config which are even less 
common than Borland.