[Bug c++/52942] [4.7 Regression] using std::ref with a std::unordered_map fails to compile

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52942

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-04-12
                 CC|                            |jwakely.gcc at gmail dot
                   |                            |com
     Ever Confirmed|0                           |1

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-04-12 01:17:46 UTC ---
Your specialization of std::hash doesn't provide the two nested types
result_type and argument_type, which are mandatory, per 20.8.12.

But another hash function meeting the Hash requirements, which do not mention
the nested types should be Ok, and looks like isn't. At the moment I completely
fail to see where we are incorrectly assuming the nested types (and, grrrr, the
error message doesn't help us much)

Jon can you see anything?