Boost logo

Boost :

Subject: Re: [boost] [preprocessor] Sequences vs. All Other Data Structures
From: Paul Mensonides (pmenso57_at_[hidden])
Date: 2012-04-27 00:45:09

On Fri, 27 Apr 2012 04:17:37 +0000, Stephan T. Lavavej wrote:

> [Paul Mensonides]
>> The best case scenario, if you want to support legacy mode: compiler
>> switch to *disable* a compliant preprocessor. I.e. do the right thing
>> _by default_ (just like with for-loop scoping).
> Yeah, you're right. I take back what I said about pragmas, I see that
> they would be especially unworkable for macros.
>> wanton macro abuse
> I was inured to defending against macroized min/max, but we recently
> discovered that Yield was macroized too - fun.

Not just min/max. Many many Windows API names too (i.e. A vs. W).
Obviously this is an issue for C without overloading, but there could be
separate C++ headers that have overloaded inline thunks. Otherwise, all
non-local (meaning locally defined, used, undefined) should be prefixed -
and- all uppercase.

Window headers aren't special (neither are other library headers... I'm
looking at you Qt and Linux (e.g. "major")) and should obey the
appropriate conventions. The Windows headers are simply garbage from the
dark ages that is inflicted on way too many users. (The same actually
goes for Qt's ridiculous signals/slots moc mechanism.) Library authors:
get it out of your heads that your library is "special." In the
particular cases of Windows and Qt, the use of either should be an
insignificant part of any software. Otherwise, the software is
fundamentally poorly designed.

This is true even for preprocessor metaprogramming libraries. The
contract library referenced in this thread, Boost.Python, the MPL, etc.,
all use Boost.Preprocessor, but the use is ultimately incidental--an
implementation detail. By definition, a library simply cannot tell how
pervasive or important it will be in a client or in a client's client (and
so on). That is *one* of the things that makes library building hard--you
often don't know whether optimization in any particular case is necessary.

Paul Mensonides

Boost list run by bdawes at, gregod at, cpdaniel at, john at