Top-level self functions `fn f(self: T)`

[scottmcm]

My 8+ year-old version of this:

Idea: Simpler method-syntax private helpers

Reading the discussion about infix method calls made me wonder how much of the problem is that it’s just annoying to make a private helper function that uses method syntax. For example, suppose you wanted to write Vec::sorted for yourself. Today it looks something like this: trait VecEx { fn sorted(self) -> Self; } impl<T: Ord> VecEx for Vec<T> { fn sorted(mut self) -> Self { self.sort(); self } } What if, instead, you could just write this? (Note the self.) fn …

Basically, solve the "how is it exported?" by having it be sugar for a voldemort trait that you can't name so can't export.

(If you do want to export it, expand it into a real extension trait.)