Ambiguous method overload with closures in Swift, but only when closure returns a value

Question

I found a behaviour in Swift\'s type resolution that I don\'t fully understand. The following example compiles. My understanding is that:

• the method im

Answer 1

You are misunderstanding what's happening. It's not about returning a value. Simplify, for a clearer demonstration of that:

func call8(_: UInt8) -> String { "8" }
func call16(_: UInt16) -> String  { "16" }

func ƒ(_ call: (UInt8) -> String) { call(8) }
func ƒ(_ call: (UInt16) -> String) { call(16) }

ƒ(call8) // "8"
ƒ(call16) // "16"

Instead, it's all about multiple lines. Read all about it!
https://forums.swift.org/t/multiline-closure-is-not-inferring-the-return-type/40013

As for the fix, you've got to explicitly type, for disambiguation.