| // 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: not %target-swift-frontend %s -typecheck |
| |
| // Issue found by https://github.com/robrix (Rob Rix) |
| // http://www.openradar.me/19924870 |
| |
| func unit<T>(x: T) -> T? { |
| return x |
| } |
| func f() -> Int? { |
| return unit(1) ?? unit(2).map { 1 } ?? nil |
| } |
