[135847] trunk/dports/science/volk

[Lawrence Velázquez]

On May 6, 2015, at 8:49 PM, Michael Dickens <michaelld at macports.org> wrote:

> * MacPorts -does not guarantee- that libstdc++ will work for C++11
> support (when using any GCC or Clang); use of it is purely on a port by
> port basis as to whether or not it will work. MacPorts will not formally
> support this configuration, even if it does work for some ports.

Mostly correct.

The issue is not really C++11; it's processes containing multiple C++ runtimes, and whether those runtimes exchange C++ objects. So that's what we actually don't support. C++11 has merely brought this issue to the forefront.

To my knowledge, mixing the system libc++ and libstdc++ (which is pre-C++11) isn't an issue because they both use the system libc++abi. The problem with MacPorts' libstdc++ is that it uses its own libsupc++ runtime.

> * MacPorts does formally support libc++ and C++11 under specific
> versions of Clang (>= 500; 3.3+). Whether using C++11 and libc++ does
> work or not then depends on the actual programming used by the port, but
> that's beyond the direct scope of what MacPorts provides and guarantees.

Right. The compiler support gets spotty prior to Clang 3.3, while the library/runtime support is fine back to Lion.

vq