multimap key_comp in C++ STL

This is the part of Standard Template Library(STL) of C++. To use this STL, use Namespace: std and include “map” header file in the program. It returns the function object or comparison object or ordering delegate that compares the keys, which is a copy of this container's constructor argument. It is a function pointer or an object that takes two arguments of the same type as the element keys and determines the order of the elements in the container. Syntax:

key_compare key_comp();

Here key_compare is the type of the comparison object, which is associated to the container. Parameters:

It does not accept any parameter.

Returns:

It returns the key comparison function object or ordering delegate, which is defined in multimap as an alias of its third template parameter.

Below is an example of multimap::key_comp: