Is the posix namespace used?

Question

The C++11 standard §17.6.4.2.2 defines posix as a reserved namespace for use by ISO/IEC 9945 and other POSIX standards, and states that C++ programs adding declarations or definitions to the posix namespace have undefined behaviour.

Is that namespace actually used by ISO/IEC 9945 or any other POSIX standards? If yes, please provide a reference.

Notes:

• N2667 was voted in in June, 2008.

Answer 1

No.

At time of writing, this is still a purely reserved namespace, not actually in use by anyone.

Recall that the vast majority of POSIX, if not all of POSIX, is entirely C++-unaware.