Represent free functions in UML

[Not a coder]

I have few functions that a user can use to access a c++ library. They are not part of any class. In UML everything belongs to a class but i cant redesign as model creation is part of reverse engineering. How can we represent functions/variables that are not a part of a class. Should i make them part of the class in whose source file they are defined or is there any other way to do it? I have tried to look but could not find answer that is helpful.

[MikeyBoy]

A simple Google search found this:

https://softwareengineering.stackexchange.com/questions/301526/uml-class-diagram-symbol-for-a-top-level-function