c++ - Erase/Remove contents from the map (or any other STL container) while iterating it

Question

Allegedly you cannot just erase/remove an element in a container while iterating as iterator becomes invalid. What are the (safe) ways to remove the elements that meet a certain condition? please only stl, no boost or tr1.

EDIT Is there a more elegant way if I want to erase a number of elements that meet a certain criteria, perhaps with using functor and for_each or erase algorithm ?

Answer 1

You can as long as you don't invalidate your iterator after you've erased it:

MyContainer::iterator it = myContainer.begin();
while(it != myContainer.end())
{
    if (*it == matchingValue)
    {
       myContainer.erase(it++);
    }
    else
    {
        ++it;
    }
}