#include <deque>

int main()
{
    std::deque<int> d;
    auto it = d.begin();
    it - 2;
}



/usr/include/c++/4.8.3/debug/safe_iterator.h:378:error: attempt to retreat 
    a past-the-end iterator 2 steps, which falls outside its valid range.

Objects involved in the operation:
iterator @ 0x0x7fff3e6b1930 {
type = N11__gnu_debug14_Safe_iteratorINSt9__cxx199815_Deque_iteratorIiRiPiEENSt7__debug5dequeIiSaIiEEEEE (mutable iterator);
  state = past-the-end;
  references sequence with type `NSt7__debug5dequeIiSaIiEEE' @ 0x0x7fff3e6b1930
}
Aborted (core dumped)

The types shown are not valid symbol names and cannot be demangled. They are missing the _Z prefix.

We should not bother printing out mangled names if users can't demangle them to get something meaningful. Ideally we should be demangling them automatically.