[Bug c++/86642] Spurious return type warning with enable_if<foo, void>

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86642

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Steinar H. Gunderson from comment #0)
> Same issue with 4.9, so no regression. Clang has the same issue.

That should have been your first clue that the problem is at your end, not in
both compilers.