[Bug c++/91618] template-id required to friend a function template, even for a qualified-id

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91618

--- Comment #4 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
to remind me, bullet 3 that Barry references is:

'if the name of the friend is a qualified-id and a matching function template
is found in the specified class or namespace, the friend declaration refers to
the deduced specialization of that function template (13.9.2.6), otherwise,'