Re: Make Closure covariant to callable

> > There are some weird cases with callable which is why they > > aren't > > allowed as a property type. I don't remember all the edges, but if we > > are sure that we cannot hit those with simple co-/contra-variance, > > then I don't think this needs an RFC and we can just merge the PR. > > The reason that callable is not allowed as a property type is due to scope/method visibility > issues. > See the discussion section of Nikita's Deprecate partially supported callables RFC: > https://wiki.php.net/rfc/deprecate_partially_supported_callables#discussion > The callable type is allowed as a parameter and return type, and Closure is "better" > defined than just callable. Then personally I see no reason to make this an RFC and would recommend merging it in as a gap in existing features (not really a new feature).