boost libstdc++ issue (was libvisio error)

[David Evans]

On 9/6/15 12:33 PM, Ryan Schmidt wrote:
> On Sep 6, 2015, at 13:43, David Evans wrote:
> 
>> It may be that boost is configuring for libc++ on 10.7, 10.8 instead of libstdc++ but, if that is the case, that is not
>> correct and would lead to the type of failure reported in this thread.
> 
> I thought it did, and that you fixed it in:
> 
> https://trac.macports.org/changeset/120994
> 
> But maybe additional fixes are needed in this new version of boost. 
> 
> Did you ever report that problem to the developers of boost? We don't want to forever maintain patches for this problem
> in MacPorts; the fixes should be committed to the boost repository. 


Wow!!  I completely forgot about doing that!!

In any case, this patch sets BOOST_APPLE_CLANG_NO_LIBCXX which apparently doesn't translate into
BOOST_NO_CXX11_RVALUE_REFERENCES and there's a whole lot of other BOOST_NO_CXX11_* macros as well.
In the current version, BOOST_APPLE_CLANG_NO_LIBCXX is used only in boost/multi_index/detail/vartempl_support.hpp,
which I think was the previous problem.

After looking at the Boost.Config documentation, I'm wondering now if using a custom user.hpp might not be a better
approach than patching clang.hpp.  Running their configure util (libs/config/configure) should run all the necessary
tests and generate a recommended user.hpp (in the cwd).  Unfortunately, I don't have a Lion system handy to see the
results myself.  Could you do this and publish the results?  I'm curious to see if BOOST_NO_CXX11_RVALUE_REFERENCES is
included.  Or whatever else is included for that matter.

I haven't mentioned this upstream as yet because I'm not really sure whether this should be considered a bug in the
Boost configuration system or just a failure on our part to add an appropriate user.hpp.  If we could come up with the
correct configuration we could ask that they include that upstream somewhere appropriate.

Dave