I'm somewhat new to programming and am unsure how to deal with a segmentation fault that appears to be coming from a std function. I hope I'm doing something stupid (i.e., misusing a container), because I have no idea how to fix it.

The precise error is

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x000000000000000c
0x00007fff8062b144 in std::_Rb_tree_rebalance_for_erase ()
(gdb) backtrace
#0 0x00007fff8062b144 in std::_Rb_tree_rebalance_for_erase ()
#1 0x000000010000e593 in Simulation::runEpidSim (this=0x7fff5fbfcb20) at stl_tree.h:1263
#2 0x0000000100016078 in main () at main.cpp:43

The function that exits successfully just before the segmentation fault updates the contents of two containers. One is a boost::unordered_multimap called carriage; it contains one or more struct Infection objects that contain two doubles. The other container is of type std::multiset< Event, std::less< Event > > EventPQ called ce. It is full of Event structs.

void Host::recover( int s, double recoverTime, EventPQ & ce ) {

  // Clearing all serotypes in carriage
  // and their associated recovery events in ce
  // and then updating susceptibility to each serotype
  double oldRecTime;
  int z;
  for ( InfectionMap::iterator itr = carriage.begin(); itr != carriage.end(); itr++ ) {
    z = itr->first;
    oldRecTime = (itr->second).recT;
    EventPQ::iterator epqItr = ce.find( Event(oldRecTime) );
    assert( epqItr != ce.end() );
    ce.erase( epqItr );
    immune[ z ]++; 
  }
  carriage.clear();
  calcSusc(); // a function that edits an array 
  cout << "Done with sync_recovery event." << endl;
}

The last cout << line appears immediately before the seg fault.

I hope this is enough (but not too much) information. My idea so far is that the rebalancing is being attempting on ce after this function, but I am unsure why it would be failing.

(It's unfortunately very hard for me to test this code by removing particular lines, since they would create logical inconsistencies and further problems, but if experienced programmers still think this is the way to go, I'll try.)