Hi ! If your actual is " can the iterator be treated like a pointer."
The answer is yes. Please read http://www.cprogramming.com/tutorial/stl/iterators.html ----- snip from the above link ------ You can think of an iterator as pointing to an item that is part of a larger container of items. For instance, all containers support a function called begin, which will return an iterator pointing to the beginning of the container (the first element) and function, end, that returns an iterator corresponding to having reached the end of the container. In fact, you can access the element by "dereferencing" the iterator with a *, just as you would dereference a pointer. ------------- Indika Bandara Udagedara wrote: > > Hi, > can you explain the life cycle of an iterator ? > > pls consider following example. > > typedef map<int, int> mapii; > typedef map<int, int>::iterator itii; > > mapii m; > pair<itii, bool> p = m.insert(make_pair(1, 2)); > itii it = p.first; > > // do all sorts of insert/erase to map > // but dont remove pair(1,2) > m.insert(0, 1); > m.insert(2, 3); > m.insert(3, 4); > // so the map would be > // 0,1 > // 1,2 <-- we are looking at here > // 2,3 > // 3,4 > > // do some erases > m.erase(2); > m.erase(0); > // so the map would be > // 1,2 <-- we are looking at here > // 3,4 > > // do some inserts > m.insert(-1, 0); > m.insert(0, 1); > m.insert(5, 6); > // so the map would be > // -1,0 > // 0,1 > // 1,2 <-- we are looking at here > // 3,4 > // 5,6 > > // now we are going to remove 'it' which we kept safely > m.erase(it); > // so the map would be > // -1,0 > // 0,1 > // 3,4 > // 5,6 > > this works as expected. but can this be guarenteed. > eg. if i do all sorts of manipulations for the map without touching > the iterator would it last ? > > one more thing. the iterator is a local variable. map returns an > iterator on insert (not a reference to an iterator). so is what i'm > doing correct? can the iterator be treated like a pointer. i tried > with moving the local iterator around functions eg. returning > iterator. it works like a pointer as i understood. > > thanks. > >
