[Bug libstdc++/78371] New: list::sort doesn't work with non-default-constructible allocators

[rs2740 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78371

            Bug ID: 78371
           Summary: list::sort doesn't work with non-default-constructible
                    allocators
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rs2740 at gmail dot com
  Target Milestone: ---

It default constructs the 1+64 temporary lists, which 1) likely does the wrong
thing for stateful allocators and 2) won't compile if the allocator used is not
default constructible.