[Bug libstdc++/60594] [4.8/4.9 Regression] std::function of a type with a declared (but not defined) return type fails to compile

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60594

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
      Known to work|                            |4.7.3
           Keywords|                            |rejects-valid
   Last reconfirmed|                            |2014-04-11
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu.org
     Ever confirmed|0                           |1
            Summary|std::function of a type     |[4.8/4.9 Regression]
                   |with a declared (but not    |std::function of a type
                   |defined) return type fails  |with a declared (but not
                   |to compile                  |defined) return type fails
                   |                            |to compile
   Target Milestone|---                         |4.8.3

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
We only need to prevent instantiation of is_convertible<bar, bar> when
evaluating the overloads for the copy constructor, the patch is simple.