いわゆる存在型の展開のうごき、少しばかり癖のある動きを見せる感じね。 #CodePiece

CodePiece.swift

protocol A {}
extension Int : A {}

func something(_ value: Any) -> String { return "Any" }
func something(_ value: some A) -> String { return "some A" }

let a: Int = 0
let b: A = 0
let c = a as A

something(a)        // "some A"
something(b)        // "some A"
something(c)        // "some A"
something(a as A)   // "Any"
something(b as A)   // "Any"
something(c as A)   // "Any"