The docs for this class state:
"Future instances are created by Executor.submit() and should not be created directly except for testing."
We have a need for a thread-safe future type in our extension but this statement makes us hesitate to use it. We don't need the executor functionality.
We can write our own future class easily enough, we're just wondering what the justification was for the limitations mentioned in the docs.
Mark Spruiell ZeroC, Inc.
It means that the API for setting results/exceptions is essentially private and may change. So if you use this you risk that your code will break randomly at some point in the future when you upgrade Python.