迭代时擦除std :: map的其他元素

Question

I have a map with following key value pairs. {(a,P),(b,Q),(c,R),(d,S),...(g,Z)}

I'm iterating this map and at each element I take a branch which access this same map and erase an element of the map if a condition is met. Simply put, it is possible that while the main iterator is at (bQ) , the branching function can erase (d,S).

Is this valid.? Or will this seg fault.?

Answer 1

You need to read the iterator invalidation rules:

std::map::erase

References and iterators to the erased elements are invalidated. Other references and iterators are not affected.

So as long as you don't use the iterator where you erased, you are good.