@swift-4.1.3import Foundation let calendar = Calendar.init(identifier: Calendar.Identifier.gregorian) DispatchQueue.concurrentPerform(iterations: 1000) { i in let timeZone = TimeZone(secondsFromGMT: 0)! let components: DateComponents = calendar.dateComponents(in: timeZone, from: Date()) }
exit status: 134 with stderr:<stdin>:7:9: warning: immutable value 'components' was never used; consider replacing with '_' or removing it let components: DateComponents = calendar.dateComponents(in: timeZone, from: Date()) ^~~~~~~~~~ _ pure virtual method called pure virtual method called terminate called without an active exception terminate called recursively pure virtual method called terminate called recursively
MacおよびiPad版のSwift Playgroundsは、楽しく遊びながらプログラミングを学べる画期的なアプリケーションです。“コードを学ぼう”レッスンでは、説明に従ってキャラクターを動かして、さまざまなステージをクリアしながら、コードの基礎を身につけます。さらに“チャレンジ”では、さまざまな課題に挑戦するユニークなコーディング体験が得られます。 Swift Playgroundsはプログラミングの知識がなくても遊べるので、12歳から112歳まで、これからプログラミングを始めようという方にピッタリです。Appleが開発し、多くの人気アプリケ...
exit status: 1 with stderr:<stdin>:13:8: error: type 'S' does not conform to protocol 'P' struct S: P { ^ <stdin>:8:18: note: ambiguous inference of associated type 'Assoc': 'some Initializable' (result of 'S.bar()') vs. 'some Initializable' (result of 'S.foo()') associatedtype Assoc ^ <stdin>:15:8: note: matching requirement 'bar()' to this declaration inferred associated type to 'some Initializable' func bar() -> some Initializable { return MyStruct() } ^ <stdin>:14:8: note: matching requirement 'foo()' to this declaration inferred associated type to 'some Initializable' func foo() -> some Initializable { return MyStruct() } ^
@swift-mainprotocol P {} extension Int: P {} func checkT<T>(_ t: T) { let tIsP1 = type(of: t) == P.self print("tIsP1=\(tIsP1)") let tIsP2 = type(of: t) is P.Type print("tIsP2=\(tIsP2)") } let a: P = 1 checkT(a)
@swift-mainprotocol P {} extension Int: P {} print(P.self is P.Type) print(P.self is P.Protocol) print(Int.self is P.Type) print(Int.self is P.Protocol)(edited)
false true true falsestderr:<stdin>:5:14: warning: 'is' test is always true print(P.self is P.Protocol) ^ <stdin>:6:16: warning: 'is' test is always true print(Int.self is P.Type) ^ <stdin>:7:16: warning: cast from 'Int.Type' to unrelated type 'P.Protocol' always fails print(Int.self is P.Protocol) ~~~~~~~~ ^ ~~~~~~~~~~(edited)
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