C multiset return key at position

Question

According to the documentation, the multiset data object contains property ordering.

As a result, for a multiset named, say, ms, it should be clear how to get the set element at a given location I such that 0 = I ms.size ().

I attempted to access these items as ms[i].

The language, however, argues that multiset does not accept subscripts.

How can I access element I in a multiset using syntax?

Answer 1

A set (or multiset) is typically represented as a tree.

As a result, key access is fairly efficient.

It is not possible to gain access using an index.

(Unlike an array, a tree does not provide random access to nodes.)

Of course, there are ingenious combinations (trees with all nodes saved in an array), but not for std::.

set vs std::multiset