Re: [boost] Boost 1.29.0 recursive_mutex With gcc On Linux

From: Alkis Evlogimenos (alkis_at_[hidden])
Date: 2002-12-20 04:14:38

On Thursday 19 December 2002 03:48 am, John Maddock wrote:
> work-around
>
> > for $BOOST_ROOT/config/compiler/gcc.hpp as follows.
>
> I don't think that we can work around this by defining _XOPEN_SOURCE in the
> boost headers: it would imply that the boost headers would have to be
> included before any other header, or nasty things will happen :-(
>
> I guess we could check for the _XOPEN_SOURCE value in posix_features.hpp as
> well as for _XOPEN_VERSION, maybe this is the right thing to do for all
> Unixes, I don't know, anyone any ideas?

http://www.opengroup.org/onlinepubs/007904975/functions/xsh_chap02_02.html#tag_02_02_01_01

According to the above link a XSI conformant application should define 
_XOPEN_SOURCE and set it to 600. So it should be defined in all posix 
compliant unices. But as you said, this should not be defined in boost 
headers as this doesn't guarantee that all system headers one may use will 
have the same feature set defined. An FAQ in the threads documentation seems 
like the least boost can do about it. Even better, albeit intrusive, if 
_XOPEN_SOURCE is not defined posix_features.hpp emits a  warning pointing the 
user to the docs and advise him to define _XOPEN_SOURCE = 600 when compiling 
his application.

-- 
Alkis