[Bug libstdc++/47437] New: libstdc++ parallel mode: multiway_merge does not compile

["singler at kit dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47437

           Summary: libstdc++ parallel mode: multiway_merge does not
                    compile
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: singler@kit.edu
                CC: singler@kit.edu, paolo.carlini@oracle.com,
                    manuel.holtgrewe@fu-berlin.de
        Depends on: 47433


Mainline currently fails to compile the parallel mode multiway merge facilities
because of a spurious mutable reference.  This is a serious regression.

The fix is easy, though, and currently undergoes testing.