Class CountValue

source code

Counter --+
          |
         CountValue

A counter class for simple, atomic memoized values.

A CountValue object should be instantiated in a class for each of the class's methods that memoizes its return value by simply storing the return value in its _memo dictionary.

We expect that the metaclass initialization will fill in the .underlying_method attribute with the method that we're wrapping. We then call the underlying_method method after counting whether its memoized value has already been set (a hit) or not (a miss).