| //===--- generic_subscript.swift ------------------------------------------===// |
| // |
| // 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-run-simple-swift |
| // REQUIRES: executable_test |
| // |
| |
| import StdlibUnittest |
| |
| |
| var GenericSubscriptTestSuite = TestSuite("GenericSubscript") |
| |
| struct S<T> : P { |
| typealias Element = T |
| var t: T |
| |
| subscript<U>(a: (T) -> U, b: (U) -> T) -> U { |
| get { |
| print(T.self) |
| print(U.self) |
| |
| return a(t) |
| } |
| set { |
| print(T.self) |
| print(U.self) |
| |
| t = b(newValue) |
| } |
| } |
| } |
| |
| protocol P { |
| associatedtype Element |
| subscript<U>(a: (Element) -> U, b: (U) -> Element) -> U { get set } |
| } |
| |
| func increment<T : P>(p: inout T) where T.Element == String { |
| p[{Int($0)!}, {String($0)}] += 1 |
| } |
| |
| GenericSubscriptTestSuite.test("Basic") { |
| var s = S<String>(t: "0") |
| increment(p: &s) |
| expectEqual(s.t, "1") |
| } |
| |
| protocol AnySubscript { |
| subscript(k: AnyHashable) -> Any? { get set } |
| } |
| |
| struct AnyDictionary : AnySubscript { |
| var dict: [AnyHashable : Any] = [:] |
| |
| subscript(k: AnyHashable) -> Any? { |
| get { |
| return dict[k] |
| } |
| set { |
| dict[k] = newValue |
| } |
| } |
| } |
| |
| extension AnySubscript { |
| subscript<K : Hashable, V>(k k: K) -> V? { |
| get { |
| return self[k] as! V? |
| } |
| set { |
| self[k] = newValue |
| } |
| } |
| } |
| |
| GenericSubscriptTestSuite.test("ProtocolExtensionConcrete") { |
| var dict = AnyDictionary() |
| |
| func doIt(dict: inout AnyDictionary) { |
| dict["a" ] = 0 |
| dict[k: "a"]! += 1 |
| } |
| |
| doIt(dict: &dict) |
| |
| expectEqual(dict["a"]! as! Int, 1) |
| expectEqual(dict[k: "a"]!, 1) |
| } |
| |
| GenericSubscriptTestSuite.test("ProtocolExtensionAbstract") { |
| var dict = AnyDictionary() |
| |
| func doIt<T : AnySubscript>(dict: inout T) { |
| dict["a" ] = 0 |
| dict[k: "a"]! += 1 |
| } |
| |
| doIt(dict: &dict) |
| |
| expectEqual(dict["a"]! as! Int, 1) |
| expectEqual(dict[k: "a"]!, 1) |
| } |
| |
| protocol GenericSubscript : AnySubscript { |
| subscript<K : Hashable, V>(k k: K) -> V? { get set } |
| } |
| |
| extension AnyDictionary : GenericSubscript { } |
| |
| GenericSubscriptTestSuite.test("ProtocolExtensionWitness") { |
| var dict = AnyDictionary() |
| |
| func doIt<T : GenericSubscript>(dict: inout T) { |
| dict["a" ] = 0 |
| dict[k: "a"]! += 1 |
| } |
| |
| doIt(dict: &dict) |
| |
| expectEqual(dict["a"]! as! Int, 1) |
| expectEqual(dict[k: "a"]!, 1) |
| } |
| |
| runAllTests() |