Obtaining list of keys and values from unordered_map

Question

What is the most efficient way of obtaining lists (as a vector) of the keys and values from an unordered_map?

For concreteness, suppose the

Answer 1

In STL there is no built-in method to get all keys or values from a map.

There is no different to iterate a unordered map or regular map, the best way is to iterate it and collect key or value to a vector.

You can write a template function to iterate any kind of map.