Boost logo

Boost :

Subject: Re: [boost] New C++14 config macros - opinions wanted
From: Mikael Persson (mikael.s.persson_at_[hidden])
Date: 2014-09-25 14:01:20

> I don't think Boost libraries should rely on these macros directly. Boost.Config,
OTOH, may use these macros to define its own macros

Agreed. I think that Boost.Config should aim to be forward-compatible with
the SD-6 macros / feature tests. What I mean is that the naming and
categorization of the features and headers should be more or less a 1-to-1
mapping to SD-6 such that at some point in the future, when many compilers
provide SD-6 feature tests, the Boost.Config macro will simply need to wrap
(or be defined by) the SD-6 macros. But, of course, you cannot rely on SD-6
for that now, but you can lay out the names and category in concert with
SG10 (and Clang dev-team too, as they are leading on this issue) to make
sure that Boost.Config and SD-6 have a harmonious future.

Doesn't everyone agree that in the best of worlds, say in 5-10 years,
Boost.Config would be nothing more than a wrapper for SD-6 macros? Wouldn't
that be wonderful maintenance-wise? No more endless tweaking for which
compiler and version supports which feature (at least, assuming compiler
vendors are honest when advertising their features through the SD-6 macros).

Oh, and you need to add a macro for n3644 "null forward iterators", because
it's an important C++14 feature ;)

That's my two-cents,


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