Using cxx11 PortGroup on < 10.9

[Michael Dickens]

My bad for thinking Mojca wanted support for libstdc++. Somehow I really
misinterpreted the original postings. Happens sometimes. - MLD

On Mon, Jan 25, 2016, at 12:11 PM, Jeremy Huddleston Sequoia wrote:
> "libstdc++" means /usr/lib/libstdc++.6.dylib, and it doesn't support
> C++11, so it is not possible to use the system libstdc++ for C++11 code. 
> I don't think we want to start supporting people using
> ${prefix}/lib/libstdc++.6.dylib from libgcc as that is quite untested and
> aiming for a world of hurt.
> 
> > compiler.whitelist macports-gcc-5 macports-gcc-4.9
> 
> This is surely not what you want.  This will cause the build to use
> ${prefix}/lib/libstdc++.6.dylib.  I could see this being useful for 10.5
> and earlier or ppc builds (because libc++ doesn't work on those
> platforms), but we don't really support those platforms any more anyways.
>  You might as well use the more-tested path of using libc++ and a
> macports-clang compiler in these cases.
> 
> To be clear, setting configure.cxx_stdlib to "libstdc++" means
> /usr/lib/libstdc++.6.dylib, it does not mean use any libstdc++ available.
>  The macports-gcc compilers don't quite work well for this scenario.  If
> you really want to support this, we'll need some new option for this
> (maybe macports-libstdc++), and dependency tracking will become quite
> difficult.