Re: [boost] [config] C++0x macros

From: Anthony Williams (anthony.ajw_at_[hidden])
Date: 2008-05-27 12:16:14

"John Maddock" <john_at_[hidden]> writes:

> anthony.ajw_at_[hidden] wrote:
>>> That's an interesting idea, although perhaps a little to cute. What
>>> do others think? Does it add value or just confuse?
>>
>> Well, for one thing it would mean that those of us who have started to
>> use the BOOST_HAS_ variants won't suddenly find our code broken.
>
> Personally I'd rather have "one true macro" for each feature or defect, if 
> necessary it's not hard to fix up the old code is it (and no I'm not 
> expecting *you* to make that change)?  Or are you using the C++0x macros in 
> non-Boost code?

No it's not hard to do the fixes, and I'm fine with doing it myself
for boost.thread.

However, I still think it's preferable to have both options at least
for a while to give people a chance to switch (as per Beman's
suggestion).

And finally, yes, I do use the boost config macros outside boost. It's
clearer to use BOOST_HAS_RVALUE_REFS than the equivalent "is this GCC
in C++0x mode" test, and it'll still work when other vendors ship
compilers with rvalue-ref support (assuming boost keeps track).

How about for 1.36.0 we provide both, and for 1.37.0 we drop the HAS
variants? This gives people (both within boost and without) a full
boost release to make the switch.

Anthony
-- 
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