Nested tuple fails to perform label conversion in ternary expression

[hamishknight]

The following fails to compile with a bad diagnostic:

func foo(_ i: Int) {
  let _: (Int, (x: Int, Bool))? = true ? (i, (i, true)) : nil
  // error: type of expression is ambiguous without a type annotation
}

However if you remove the first element i and the associated Int from the type annotation, it succeeds. It also succeeds if you remove the ternary.

[jamieQ]

also note that it appears the optional may not be necessary:

func foo(_ x: Int) {
  let _: (Int, (x: Int, Bool)) = true ? (x, (x, true)) : (x, (x, false))
  // error: type of expression is ambiguous without a type annotation
}