The solution to this is to not use exceptions except for actual errors, unless it's going to be amortized away. For example, objects which have a heavy paramet

The solution to this is to not use exceptions except for actual errors, unless it's going to be amortized away. For example, objects which have a heavy parameter, which gets memoized. With the zero-cost happy path, you only raise the exception once, when you're doing the costly thing, and subsequent accesses are free.