Can you remove elements from a std::list while iterating through it?

Question

I\'ve got code that looks like this:

for (std::list::iterator i=items.begin();i!=items.end();i++)
{
    bool isActive = (*i)->update();
    /         


        

Answer 1

You have to increment the iterator first (with i++) and then remove the previous element (e.g., by using the returned value from i++). You can change the code to a while loop like so:

std::list::iterator i = items.begin();
while (i != items.end())
{
    bool isActive = (*i)->update();
    if (!isActive)
    {
        items.erase(i++);  // alternatively, i = items.erase(i);
    }
    else
    {
        other_code_involving(*i);
        ++i;
    }
}