Lived Experiences: Strange match ergonomics

[scottmcm]

@rpjohnst

This has been “broken” since before 1.0. let x = y; already “radically differs” in owning vs borrowing based on whether y is a reference. All match ergonomics does is allow this sort of thing to pass through patterns, by eliding part of the structure of types (the part built out of references).

I think this is an interesting argument for something like Random Musings: types in patterns : the way this is dealt with in that case is by adding a type (x in let x: u32 = y; is definitely not a borrow), so the same would work inside a pattern (x in let Struct { x: i32 } = y; is definitely not a borrow).