MaybeRate

The names of the product elements

The name of the type

Constructs an optional rate from a given identifier. -1 denotes the UndefinedRate, values >= 0 denote the identifier of a defined rate.

Calculates the maximum rate among a list of optional rates. If the list is empty or contains at least one UndefinedRate, the return value is also UndefinedRate.

Calculates the minimum rate among a list of optional rates. If the list is empty or contains at least one UndefinedRate, the return value is also UndefinedRate.

Reduces a list of optional rates to one value. If the list is empty or contains different rates, the return value is UndefinedRate. Otherwise, if all elements are equal, returns that one rate.