Dictionary error: Ambiguous reference to member '+' [duplicate]

Answer 1

This code has been compiled successfully:

let dict = ["A": 1, "B": 2, "C": 3]
let one = dict["A"]!
let two = dict["B"]!
let three = dict["C"]!
let sum = one + two + three

I guess, this problem related to complex expressions. You can read more about build time optimisation in this article.