Technically this is feasible, but I don't think that it's a good idea to surprise user with impurity of pure function.
> This is extremely restrictive, and not currently enforced. > Two specific limitations: > - a 'pure' member function doesn't really make sense (could only be > called on an immutable class) > - a pure function cannot have 'out' parameters. If you can't use purity, don't use it, impure functions work just fine.
