My bimap implementation bimap
A bimap is a data structure that stores a set of pairs and efficiently searches for a key by value. Unlike map, the search in bimap can be performed both on the left (left) elements of pairs, and on the right (right).
bimap is parameterized by 2 types (left and right) and 2 comparators that determine the order on these types.
The bimap iterator repeats the corresponding behavior for map and allows passing all elements on one side in the order determined by the passed comparator.