| // This source file is part of the Swift.org open source project |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| |
| // RUN: %target-swift-frontend %s -typecheck |
| // Discovered by https://github.com/airspeedswift (airspeedswift) |
| |
| let s1: Set<Int>? = [] |
| let s2: Set<Int>? = [] |
| let s3: Set<Int>? = [] |
| let x = s1 ?? s2 ?? s3 ?? [] |
