Suggest transferring `complete()` to `generics` package

[stefvanbuuren]

I’d like to suggest transferring the complete() generic function to the generics package.

Context

The mice package defines its own mice::complete() function, which uses the same verb but serves a different purpose than tidyr::complete(). To prevent confusion and potential name clashes when users load both mice and tidyr, I import tidyr::complete() explicitly, following the solution described in tidyr#390.

However, this small import causes mice to inherit a large set of dependencies from tidyr, even though mice does not use any of its other functionality.

Request

Would you consider moving the complete() generic to the generics package, similar to how functions like predict(), tidy(), and augment() have been handled?

This would allow packages like mice to register methods for complete() cleanly and without needing to import tidyr (or introduce a Suggests/Depends relationship).

Thank you for considering.