What should be the default `self` for methods on Copy types?


Suppose I have some X: Copy

If I write

impl X {
    fn foo(???self) { }

what is the preferable form of self, &self or self? Because the type is Copy, both would work fine.

The argument for &self is consistency. The argument for self is that there are no lifetimes, which can save you from lifetime miselision (In my case, I had X<'f>: Copy and wanted fn foo(&self) -> Y<'f>, while lifetime elision has given me fn foo(&'a self) -> Y<'a>).