[boost] autoconf [was Re: [filesysteam] dirent::d_type extension availability?]

From: Beman Dawes (bdawes_at_[hidden])
Date: 2005-12-17 09:46:15

"Neal Becker" <ndbecker2_at_[hidden]> wrote in message 
news:do10iu$dj1$1_at_sea.gmane.org...
> Neal Becker wrote:
>
>> Beman Dawes wrote:
>>
>>> The directory iterator value type objects now caches status information.
>>> Performance is much better (6 times, in one test).
>>>
>>> This optimization is present for the Windows API, and for POSIX systems
>>> which support the BSD dirent::d_type extension. Currently this is
>>> detected by the __USE_BSD macro. Please report other macros which
>>> indicate it is safe to turn on this feature.
>>>
>>> IIRC, someone indicated that Linux also supports the feature, but
>>> perhaps only on later versions. If that is the case, what is the correct
>>>   macros to be tested for what values?
>>>
>
> To be more precise: this is not a feature of Linux - it's a feature of the 
> c
> lib.  Linux systems ususally use glibc, but small embedded systems may use
> other clibs, such as ulibc.  This is why lots of people gave up on "guess
> the macro" years ago and changed to some kind of autoconf.  There are too
> many variables.

Yes, I can see the advantages of that approach.

Probably because I don't have any autoconf experience, I have trouble seeing 
how we could make use of that approach for Boost.

Any ideas?

--Beman