Question

Assume I have a nested map of type pointer. Then is there a single line statement to insert into the nested map,

map<int, map<int, int> >* nestedMap;

Currently I am doing this in 2 steps. First creating innermap and then insert into outer map as below,

nestedMap->insert(make_pair(int, map<int, int>)(int, innermap));

If the map is not pointer type, then i can insert easily like this,

nestedMap[int][int] = int;

Is there any simple ways for inserting into nested map of type pointer ?

thanks
Prabu

Answer 1

map::operator[] automatically creates the key/value pair if it doesn’t exist.
(That’s why it’s not const!)
So you don’t need to create the inner map manually.

If you want to avoid creating the pair automatically, then use map::find() or map::at().