A type that provides a bidirectional iterator that can read a const element in the multimap.
A type const_iterator cannot be used to modify the value of an element.
The const_iterator defined by multimap points to objects of value_type, which are of type pair<const Key, Type>. The value of the key is available through the first member pair and the value of the mapped element is available through the second member of the pair.
To dereference a const_iterator cIter pointing to an element in a multimap, use the -> operator.
To access the value of the key for the element, use cIter -> first, which is equivalent to (*cIter).first. To access the value of the mapped datum for the element, use cIter -> second, which is equivalent to (*cIter).second.