[Bug libstdc++/55043] [4.7/4.8 Regression] issue with nesting unordered_map containing unique_ptr into vector

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55043

--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-24 09:10:38 UTC ---
Ah yes, you're right.

So to make the testcase compile (which it should) I'd need to use sfinae to
disable the container members, which means writing constraints based on
CopyInsertable etc which depend on the allocator type, so allocator_traits
needs to also use sfinae to disable ill-formed 'construct' calls, which may not
be possible to detect, because errors may still not be in the immediate
context. Damn.