H. S. Teoh:
IMO, if you need to be changing stuff inside invariants, then you're using it wrong. Invariants are intended to verify program logic, not to do things like altering object state. The point is to be able to compile with invariant code turned off, and still have the program work exactly as before.
I agree, modifying the state of the struct/class instance is not the job of contracts and invariants. D contract programming is already not tidy, so better to not make it even more messy.
In a perfect world invariants and contracts should be pure too! Bye, bearophile
