Using cxx11 PortGroup on < 10.9

[Mojca Miklavec]

On 25 January 2016 at 18:11, Jeremy Huddleston Sequoia wrote:
>> On Jan 25, 2016, at 08:04, Michael Dickens wrote:
>>
>> We've had this discuss before, how to do C++11 for libstdc++ and libc++.
>>
>> The cxx11 PortGroup implements C++11 compliance for libc++ only. It
>> errors out when using libstdc++.
>>
>> What Mojca is asking is whether we can add an implementation for when
>> using libstdc++
>
> "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.

Just to clarify. I don't want to "support" anyone building C++11 code
against /usr/lib/libstdc++.6.dylib.

I would like to support building C++11 code against libc++ for users
who have not modified their stdlib setting yet (that includes the
buildbots) and for a small subset of ports where doing that doesn't
actually lead to crashes and problems. Examples include clang-3.7,
root6 etc.

But I agree that one can in principle do that without the portgroup.

(Even more than that I would really like to see the buildbots with
libc++ as their default stdlib being set up.)

Then again ... the longer we postpone this action, the less people
will feel that it would have to be done at all and the smaller the
chances will be that we would be able to fix remaining problems.

Mojca