Warning C28023

The function being assigned or passed should have a _Function_class_ annotation for at least one of the class(es) in: 'classlist'

This warning is often reported when only one function class is in use and a callback of the appropriate type isn't declared.

This warning is issued when the function on the left side of the assignment (or of the implied assignment, if it's a function call) is annotated to indicate that it's a driver-specific function type that uses the _Function_class_ annotation, or a typedef that contains such an annotation. The function on the right side of the assignment doesn't have a _Function_class_ annotation. The function on the right should be annotated to be of the same type as the function on the left. Often the best approach is to place the declaration <class1> <funcname1> before the current first declaration of <funcname2>.