[Bug c++/51989] std::deque::iterator recognised as container

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51989

--- Comment #9 from Jason Merrill <jason at gcc dot gnu.org> 2012-01-25 
17:32:12 UTC ---
(In reply to comment #5)
> Jason, shouldn't deduction fail for ((U*)0)->foo() with U=void instead of
> giving an error?

Yep.  Need to pass complain into build_x_arrow.