Having trouble using an STL map's iterator while removing elements

Question

I'm looping through an STL map to delete elements and do some clean up. Unfortunately for me my program crashes on the ++iter line. Am I doing something wrong in how I'm looping over the map?

std::map<string,BoneHierarchy* >::iterator iter = boneMap.begin();
while(iter != boneMap.end()) {
    string playerName = iter->first;
    boneMap[playerName]->clear();
    boneQueue->push(boneMap[playerName]);
    boneMap.erase(iter);
    ++iter;
}

Answer 1

Don't increment the iterator after deleting it (it's been erased, so how can you expect to increment it?). Erase a copy of the iterator with:

boneMap.erase(iter++);

or do

iter = boneMap.erase(iter);

if using C++11.

(See also Removing elements from a C++ map through a for-loop )

Answer 2

boneMap.erase(iter);
++iter;                     //incorrect

should be written as:

iter = boneMap.erase(iter); //correct (in C++11)
//no need to increment!

Because map::erase() returns iterator following the erased item .