On Friday, 2 October 2020 at 23:03:49 UTC, Ola Fosheim Grøstad wrote: > > I have no issues with undefined behaviour as long as it is easy > to understand and explain, like requiring 'in' params to be > nonaliased in the function body. It has to be easy to grok and > remember. Or the even simpler rule: don't use 'in' :)