G++ namespace association extension

[Jonathan Wakely]

http://gcc.gnu.org/onlinedocs/gcc/Namespace-Association.html says:

"Caution: The semantics of this extension are not fully defined. Users
should refrain from using this extension as its semantics may change
subtly over time. It is possible that this extension will be removed
in future versions of G++. "

Is it safe to assume that the semantics are now fixed to match those
of C++11 inline namespaces and will not change unless removed?

If so I'll prepare a patch for the manual.