[Bug libstdc++/60519] New: Debug mode should check comparators for irreflexivity

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60519

            Bug ID: 60519
           Summary: Debug mode should check comparators for irreflexivity
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org

We could avoid a number of INVALID bug reports (e.g. PR59391) if Debug Mode did
this in <algorithm>

#ifdef _GLIBCXX_DEBUG
if (first < last)
    __glibcxx_assert( !cmp(*first, *first) );
#endif