// RUN: %target-typecheck-verify-swift -swift-version 3 // Tests for tuple argument behavior in Swift 3, which was broken. // The Swift 4 test is in test/Compatibility/tuple_arguments_4.swift. // The test for the most recent version is in test/Constraints/tuple_arguments.swift. // Key: // - "Crashes in actual Swift 3" -- snippets which crashed in Swift 3.0.1. // These don't have well-defined semantics in Swift 3 mode and don't // matter for source compatibility purposes. // // - "Does not diagnose in Swift 3 mode" -- snippets which failed to typecheck // in Swift 3.0.1, but now typecheck. This is fine. // // - "Diagnoses in Swift 3 mode" -- snippets which typechecked in Swift 3.0.1, // but now fail to typecheck. These are bugs in Swift 3 mode that should be // fixed. // // - "Crashes in Swift 3 mode" -- snippets which did not crash Swift 3.0.1, // but now crash. These are bugs in Swift 3 mode that should be fixed. func concrete(_ x: Int) {} func concreteLabeled(x: Int) {} func concreteTwo(_ x: Int, _ y: Int) {} // expected-note 3 {{'concreteTwo' declared here}} func concreteTuple(_ x: (Int, Int)) {} do { concrete(3) concrete((3)) concreteLabeled(x: 3) concreteLabeled(x: (3)) concreteLabeled((x: 3)) // expected-error {{missing argument label 'x:' in call}} concreteTwo(3, 4) concreteTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} concreteTuple(3, 4) // expected-error {{global function 'concreteTuple' expects a single parameter of type '(Int, Int)'}} {{17-17=(}} {{21-21=)}} concreteTuple((3, 4)) } do { let a = 3 let b = 4 let c = (3) let d = (a, b) concrete(a) concrete((a)) concrete(c) concreteTwo(a, b) concreteTwo((a, b)) concreteTwo(d) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} concreteTuple(a, b) concreteTuple((a, b)) concreteTuple(d) } do { var a = 3 var b = 4 var c = (3) var d = (a, b) concrete(a) concrete((a)) concrete(c) concreteTwo(a, b) concreteTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} concreteTwo(d) // expected-error {{missing argument for parameter #2 in call}} concreteTuple(a, b) // expected-error {{global function 'concreteTuple' expects a single parameter of type '(Int, Int)'}} {{17-17=(}} {{21-21=)}} concreteTuple((a, b)) concreteTuple(d) } func generic(_ x: T) {} func genericLabeled(x: T) {} func genericTwo(_ x: T, _ y: U) {} // expected-note 5 {{'genericTwo' declared here}} func genericTuple(_ x: (T, U)) {} do { generic(3) generic(3, 4) generic((3)) generic((3, 4)) genericLabeled(x: 3) genericLabeled(x: 3, 4) // expected-error {{extra argument in call}} genericLabeled(x: (3)) genericLabeled(x: (3, 4)) genericTwo(3, 4) genericTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} genericTuple(3, 4) // expected-error {{global function 'genericTuple' expects a single parameter of type '(T, U)'}} {{16-16=(}} {{20-20=)}} genericTuple((3, 4)) } do { let a = 3 let b = 4 let c = (3) let d = (a, b) generic(a) generic(a, b) generic((a)) generic(c) generic((a, b)) generic(d) genericTwo(a, b) genericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} genericTwo(d) // expected-error {{missing argument for parameter #2 in call}} genericTuple(a, b) // expected-error {{global function 'genericTuple' expects a single parameter of type '(T, U)'}} {{16-16=(}} {{20-20=)}} genericTuple((a, b)) genericTuple(d) } do { var a = 3 var b = 4 var c = (3) var d = (a, b) generic(a) // generic(a, b) // Crashes in actual Swift 3 generic((a)) generic(c) generic((a, b)) generic(d) genericTwo(a, b) genericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} genericTwo(d) // expected-error {{missing argument for parameter #2 in call}} genericTuple(a, b) // expected-error {{global function 'genericTuple' expects a single parameter of type '(T, U)'}} {{16-16=(}} {{20-20=)}} genericTuple((a, b)) genericTuple(d) } var function: (Int) -> () var functionTwo: (Int, Int) -> () // expected-note 3 {{'functionTwo' declared here}} var functionTuple: ((Int, Int)) -> () do { function(3) function((3)) functionTwo(3, 4) functionTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} functionTuple(3, 4) // expected-error {{var 'functionTuple' expects a single parameter of type '(Int, Int)'}} {{17-17=(}} {{21-21=)}} functionTuple((3, 4)) } do { let a = 3 let b = 4 let c = (3) let d = (a, b) function(a) function((a)) function(c) functionTwo(a, b) functionTwo((a, b)) functionTwo(d) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} functionTuple(a, b) functionTuple((a, b)) functionTuple(d) } do { var a = 3 var b = 4 var c = (3) var d = (a, b) function(a) function((a)) function(c) functionTwo(a, b) functionTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} functionTwo(d) // expected-error {{missing argument for parameter #2 in call}} functionTuple(a, b) // expected-error {{var 'functionTuple' expects a single parameter of type '(Int, Int)'}} {{17-17=(}} {{21-21=)}} functionTuple((a, b)) functionTuple(d) } struct Concrete {} extension Concrete { func concrete(_ x: Int) {} func concreteTwo(_ x: Int, _ y: Int) {} // expected-note 3 {{'concreteTwo' declared here}} func concreteTuple(_ x: (Int, Int)) {} } do { let s = Concrete() s.concrete(3) s.concrete((3)) s.concreteTwo(3, 4) s.concreteTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} s.concreteTuple(3, 4) // expected-error {{instance method 'concreteTuple' expects a single parameter of type '(Int, Int)'}} {{19-19=(}} {{23-23=)}} s.concreteTuple((3, 4)) } do { let s = Concrete() let a = 3 let b = 4 let c = (3) let d = (a, b) s.concrete(a) s.concrete((a)) s.concrete(c) s.concreteTwo(a, b) s.concreteTwo((a, b)) s.concreteTwo(d) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} s.concreteTuple(a, b) s.concreteTuple((a, b)) s.concreteTuple(d) } do { var s = Concrete() var a = 3 var b = 4 var c = (3) var d = (a, b) s.concrete(a) s.concrete((a)) s.concrete(c) s.concreteTwo(a, b) s.concreteTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.concreteTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.concreteTuple(a, b) // expected-error {{instance method 'concreteTuple' expects a single parameter of type '(Int, Int)'}} {{19-19=(}} {{23-23=)}} s.concreteTuple((a, b)) s.concreteTuple(d) } extension Concrete { func generic(_ x: T) {} func genericLabeled(x: T) {} func genericTwo(_ x: T, _ y: U) {} // expected-note 5 {{'genericTwo' declared here}} func genericTuple(_ x: (T, U)) {} } do { let s = Concrete() s.generic(3) s.generic(3, 4) s.generic((3)) s.generic((3, 4)) s.genericLabeled(x: 3) s.genericLabeled(x: 3, 4) // expected-error {{extra argument in call}} s.genericLabeled(x: (3)) s.genericLabeled(x: (3, 4)) s.genericTwo(3, 4) s.genericTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} s.genericTuple(3, 4) // expected-error {{instance method 'genericTuple' expects a single parameter of type '(T, U)'}} {{18-18=(}} {{22-22=)}} s.genericTuple((3, 4)) } do { let s = Concrete() let a = 3 let b = 4 let c = (3) let d = (a, b) s.generic(a) s.generic(a, b) s.generic((a)) s.generic((a, b)) s.generic(d) s.genericTwo(a, b) s.genericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.genericTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.genericTuple(a, b) // expected-error {{instance method 'genericTuple' expects a single parameter of type '(T, U)'}} {{18-18=(}} {{22-22=)}} s.genericTuple((a, b)) s.genericTuple(d) } do { var s = Concrete() var a = 3 var b = 4 var c = (3) var d = (a, b) s.generic(a) // s.generic(a, b) // Crashes in actual Swift 3 s.generic((a)) s.generic((a, b)) s.generic(d) s.genericTwo(a, b) s.genericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.genericTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.genericTuple(a, b) // expected-error {{instance method 'genericTuple' expects a single parameter of type '(T, U)'}} {{18-18=(}} {{22-22=)}} s.genericTuple((a, b)) s.genericTuple(d) } extension Concrete { mutating func mutatingConcrete(_ x: Int) {} mutating func mutatingConcreteTwo(_ x: Int, _ y: Int) {} // expected-note 3 {{'mutatingConcreteTwo' declared here}} mutating func mutatingConcreteTuple(_ x: (Int, Int)) {} } do { var s = Concrete() s.mutatingConcrete(3) s.mutatingConcrete((3)) s.mutatingConcreteTwo(3, 4) s.mutatingConcreteTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingConcreteTuple(3, 4) // expected-error {{instance method 'mutatingConcreteTuple' expects a single parameter of type '(Int, Int)'}} {{27-27=(}} {{31-31=)}} s.mutatingConcreteTuple((3, 4)) } do { var s = Concrete() let a = 3 let b = 4 let c = (3) let d = (a, b) s.mutatingConcrete(a) s.mutatingConcrete((a)) s.mutatingConcrete(c) s.mutatingConcreteTwo(a, b) s.mutatingConcreteTwo((a, b)) s.mutatingConcreteTwo(d) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} s.mutatingConcreteTuple(a, b) s.mutatingConcreteTuple((a, b)) s.mutatingConcreteTuple(d) } do { var s = Concrete() var a = 3 var b = 4 var c = (3) var d = (a, b) s.mutatingConcrete(a) s.mutatingConcrete((a)) s.mutatingConcrete(c) s.mutatingConcreteTwo(a, b) s.mutatingConcreteTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingConcreteTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.mutatingConcreteTuple(a, b) // expected-error {{instance method 'mutatingConcreteTuple' expects a single parameter of type '(Int, Int)'}} {{27-27=(}} {{31-31=)}} s.mutatingConcreteTuple((a, b)) s.mutatingConcreteTuple(d) } extension Concrete { mutating func mutatingGeneric(_ x: T) {} mutating func mutatingGenericLabeled(x: T) {} mutating func mutatingGenericTwo(_ x: T, _ y: U) {} // expected-note 5 {{'mutatingGenericTwo' declared here}} mutating func mutatingGenericTuple(_ x: (T, U)) {} } do { var s = Concrete() s.mutatingGeneric(3) s.mutatingGeneric(3, 4) s.mutatingGeneric((3)) s.mutatingGeneric((3, 4)) s.mutatingGenericLabeled(x: 3) s.mutatingGenericLabeled(x: 3, 4) // expected-error {{extra argument in call}} s.mutatingGenericLabeled(x: (3)) s.mutatingGenericLabeled(x: (3, 4)) s.mutatingGenericTwo(3, 4) s.mutatingGenericTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTuple(3, 4) // expected-error {{instance method 'mutatingGenericTuple' expects a single parameter of type '(T, U)'}} {{26-26=(}} {{30-30=)}} s.mutatingGenericTuple((3, 4)) } do { var s = Concrete() let a = 3 let b = 4 let c = (3) let d = (a, b) s.mutatingGeneric(a) s.mutatingGeneric(a, b) s.mutatingGeneric((a)) s.mutatingGeneric((a, b)) s.mutatingGeneric(d) s.mutatingGenericTwo(a, b) s.mutatingGenericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTuple(a, b) // expected-error {{instance method 'mutatingGenericTuple' expects a single parameter of type '(T, U)'}} {{26-26=(}} {{30-30=)}} s.mutatingGenericTuple((a, b)) s.mutatingGenericTuple(d) } do { var s = Concrete() var a = 3 var b = 4 var c = (3) var d = (a, b) s.mutatingGeneric(a) // s.mutatingGeneric(a, b) // Crashes in actual Swift 3 s.mutatingGeneric((a)) s.mutatingGeneric((a, b)) s.mutatingGeneric(d) s.mutatingGenericTwo(a, b) s.mutatingGenericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTuple(a, b) // expected-error {{instance method 'mutatingGenericTuple' expects a single parameter of type '(T, U)'}} {{26-26=(}} {{30-30=)}} s.mutatingGenericTuple((a, b)) s.mutatingGenericTuple(d) } extension Concrete { var function: (Int) -> () { return concrete } var functionTwo: (Int, Int) -> () { return concreteTwo } var functionTuple: ((Int, Int)) -> () { return concreteTuple } } do { let s = Concrete() s.function(3) s.function((3)) s.functionTwo(3, 4) s.functionTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} s.functionTuple(3, 4) // expected-error {{single parameter of type '(Int, Int)' is expected in call}} {{19-19=(}} {{23-23=)}} s.functionTuple((3, 4)) } do { let s = Concrete() let a = 3 let b = 4 let c = (3) let d = (a, b) s.function(a) s.function((a)) s.function(c) s.functionTwo(a, b) s.functionTwo((a, b)) s.functionTwo(d) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} s.functionTuple(a, b) s.functionTuple((a, b)) s.functionTuple(d) } do { var s = Concrete() var a = 3 var b = 4 var c = (3) var d = (a, b) s.function(a) s.function((a)) s.function(c) s.functionTwo(a, b) s.functionTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.functionTwo(d) // expected-error {{missing argument for parameter #2 in call}} s.functionTuple(a, b) // expected-error {{single parameter of type '(Int, Int)' is expected in call}} {{19-19=(}} {{23-23=)}} s.functionTuple((a, b)) s.functionTuple(d) } struct InitTwo { init(_ x: Int, _ y: Int) {} // expected-note 3 {{'init' declared here}} } struct InitTuple { init(_ x: (Int, Int)) {} } struct InitLabeledTuple { init(x: (Int, Int)) {} } do { _ = InitTwo(3, 4) _ = InitTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} _ = InitTuple(3, 4) // expected-error {{initializer expects a single parameter of type '(Int, Int)'}} {{17-17=(}} {{21-21=)}} _ = InitTuple((3, 4)) _ = InitLabeledTuple(x: 3, 4) // expected-error {{initializer expects a single parameter of type '(Int, Int)'}} _ = InitLabeledTuple(x: (3, 4)) } do { let a = 3 let b = 4 let c = (a, b) _ = InitTwo(a, b) _ = InitTwo((a, b)) _ = InitTwo(c) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} _ = InitTuple(a, b) _ = InitTuple((a, b)) _ = InitTuple(c) } do { var a = 3 var b = 4 var c = (a, b) _ = InitTwo(a, b) _ = InitTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = InitTwo(c) // expected-error {{missing argument for parameter #2 in call}} _ = InitTuple(a, b) // expected-error {{initializer expects a single parameter of type '(Int, Int)'}} {{17-17=(}} {{21-21=)}} _ = InitTuple((a, b)) _ = InitTuple(c) } struct SubscriptTwo { subscript(_ x: Int, _ y: Int) -> Int { get { return 0 } set { } } // expected-note 3 {{'subscript' declared here}} } struct SubscriptTuple { subscript(_ x: (Int, Int)) -> Int { get { return 0 } set { } } } struct SubscriptLabeledTuple { subscript(x x: (Int, Int)) -> Int { get { return 0 } set { } } } do { let s1 = SubscriptTwo() _ = s1[3, 4] _ = s1[(3, 4)] // expected-error {{missing argument for parameter #2 in call}} let s2 = SubscriptTuple() _ = s2[3, 4] // expected-error {{subscript expects a single parameter of type '(Int, Int)'}} {{10-10=(}} {{14-14=)}} _ = s2[(3, 4)] let s3 = SubscriptLabeledTuple() _ = s3[x: 3, 4] // expected-error {{subscript expects a single parameter of type '(Int, Int)'}} _ = s3[x: (3, 4)] } do { let a = 3 let b = 4 let d = (a, b) let s1 = SubscriptTwo() _ = s1[a, b] _ = s1[(a, b)] _ = s1[d] let s2 = SubscriptTuple() _ = s2[a, b] _ = s2[(a, b)] _ = s2[d] } do { // TODO: Restore regressed diagnostics rdar://problem/31724211 var a = 3 var b = 4 var d = (a, b) var s1 = SubscriptTwo() _ = s1[a, b] _ = s1[(a, b)] // expected-error {{missing argument for parameter #2 in call}} _ = s1[d] // expected-error {{missing argument for parameter #2 in call}} var s2 = SubscriptTuple() _ = s2[a, b] // expected-error {{subscript expects a single parameter of type '(Int, Int)'}} {{10-10=(}} {{14-14=)}} _ = s2[(a, b)] _ = s2[d] } enum Enum { case two(Int, Int) // expected-note 3 {{'two' declared here}} case tuple((Int, Int)) case labeledTuple(x: (Int, Int)) } do { _ = Enum.two(3, 4) _ = Enum.two((3, 4)) // expected-error {{missing argument for parameter #2 in call}} _ = Enum.tuple(3, 4) // expected-error {{enum element 'tuple' expects a single parameter of type '(Int, Int)'}} {{18-18=(}} {{22-22=)}} _ = Enum.tuple((3, 4)) _ = Enum.labeledTuple(x: 3, 4) // expected-error {{enum element 'labeledTuple' expects a single parameter of type '(Int, Int)'}} _ = Enum.labeledTuple(x: (3, 4)) } do { let a = 3 let b = 4 let c = (a, b) _ = Enum.two(a, b) _ = Enum.two((a, b)) _ = Enum.two(c) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} _ = Enum.tuple(a, b) _ = Enum.tuple((a, b)) _ = Enum.tuple(c) } do { var a = 3 var b = 4 var c = (a, b) _ = Enum.two(a, b) _ = Enum.two((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = Enum.two(c) // expected-error {{missing argument for parameter #2 in call}} _ = Enum.tuple(a, b) // expected-error {{enum element 'tuple' expects a single parameter of type '(Int, Int)'}} {{18-18=(}} {{22-22=)}} _ = Enum.tuple((a, b)) _ = Enum.tuple(c) } struct Generic {} extension Generic { func generic(_ x: T) {} func genericLabeled(x: T) {} func genericTwo(_ x: T, _ y: T) {} // expected-note 2 {{'genericTwo' declared here}} func genericTuple(_ x: (T, T)) {} } do { let s = Generic() s.generic(3.0) s.generic((3.0)) s.genericLabeled(x: 3.0) s.genericLabeled(x: (3.0)) s.genericTwo(3.0, 4.0) s.genericTwo((3.0, 4.0)) // expected-error {{missing argument for parameter #2 in call}} s.genericTuple(3.0, 4.0) // expected-error {{instance method 'genericTuple' expects a single parameter of type '(Double, Double)'}} {{18-18=(}} {{26-26=)}} s.genericTuple((3.0, 4.0)) let sTwo = Generic<(Double, Double)>() sTwo.generic(3.0, 4.0) // expected-error {{instance method 'generic' expects a single parameter of type '(Double, Double)'}} {{16-16=(}} {{24-24=)}} sTwo.generic((3.0, 4.0)) sTwo.genericLabeled(x: 3.0, 4.0) // expected-error {{instance method 'genericLabeled' expects a single parameter of type '(Double, Double)'}} sTwo.genericLabeled(x: (3.0, 4.0)) } do { let s = Generic() let a = 3.0 let b = 4.0 let c = (3.0) let d = (a, b) s.generic(a) s.generic((a)) s.generic(c) s.genericTwo(a, b) s.genericTwo((a, b)) s.genericTuple(a, b) s.genericTuple((a, b)) let sTwo = Generic<(Double, Double)>() sTwo.generic(a, b) sTwo.generic((a, b)) sTwo.generic(d) } do { var s = Generic() var a = 3.0 var b = 4.0 var c = (3.0) var d = (a, b) s.generic(a) s.generic((a)) s.generic(c) s.genericTwo(a, b) s.genericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.genericTuple(a, b) // expected-error {{instance method 'genericTuple' expects a single parameter of type '(Double, Double)'}} {{18-18=(}} {{22-22=)}} s.genericTuple((a, b)) var sTwo = Generic<(Double, Double)>() sTwo.generic(a, b) // expected-error {{instance method 'generic' expects a single parameter of type '(Double, Double)'}} {{16-16=(}} {{20-20=)}} sTwo.generic((a, b)) sTwo.generic(d) } extension Generic { mutating func mutatingGeneric(_ x: T) {} mutating func mutatingGenericLabeled(x: T) {} mutating func mutatingGenericTwo(_ x: T, _ y: T) {} // expected-note 2 {{'mutatingGenericTwo' declared here}} mutating func mutatingGenericTuple(_ x: (T, T)) {} } do { var s = Generic() s.mutatingGeneric(3.0) s.mutatingGeneric((3.0)) s.mutatingGenericLabeled(x: 3.0) s.mutatingGenericLabeled(x: (3.0)) s.mutatingGenericTwo(3.0, 4.0) s.mutatingGenericTwo((3.0, 4.0)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTuple(3.0, 4.0) // expected-error {{instance method 'mutatingGenericTuple' expects a single parameter of type '(Double, Double)'}} {{26-26=(}} {{34-34=)}} s.mutatingGenericTuple((3.0, 4.0)) var sTwo = Generic<(Double, Double)>() sTwo.mutatingGeneric(3.0, 4.0) // expected-error {{instance method 'mutatingGeneric' expects a single parameter of type '(Double, Double)'}} {{24-24=(}} {{32-32=)}} sTwo.mutatingGeneric((3.0, 4.0)) sTwo.mutatingGenericLabeled(x: 3.0, 4.0) // expected-error {{instance method 'mutatingGenericLabeled' expects a single parameter of type '(Double, Double)'}} sTwo.mutatingGenericLabeled(x: (3.0, 4.0)) } do { var s = Generic() let a = 3.0 let b = 4.0 let c = (3.0) let d = (a, b) s.mutatingGeneric(a) s.mutatingGeneric((a)) s.mutatingGeneric(c) s.mutatingGenericTwo(a, b) s.mutatingGenericTwo((a, b)) s.mutatingGenericTuple(a, b) s.mutatingGenericTuple((a, b)) var sTwo = Generic<(Double, Double)>() sTwo.mutatingGeneric(a, b) sTwo.mutatingGeneric((a, b)) sTwo.mutatingGeneric(d) } do { var s = Generic() var a = 3.0 var b = 4.0 var c = (3.0) var d = (a, b) s.mutatingGeneric(a) s.mutatingGeneric((a)) s.mutatingGeneric(c) s.mutatingGenericTwo(a, b) s.mutatingGenericTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.mutatingGenericTuple(a, b) // expected-error {{instance method 'mutatingGenericTuple' expects a single parameter of type '(Double, Double)'}} {{26-26=(}} {{30-30=)}} s.mutatingGenericTuple((a, b)) var sTwo = Generic<(Double, Double)>() sTwo.mutatingGeneric(a, b) // expected-error {{instance method 'mutatingGeneric' expects a single parameter of type '(Double, Double)'}} {{24-24=(}} {{28-28=)}} sTwo.mutatingGeneric((a, b)) sTwo.mutatingGeneric(d) } extension Generic { var genericFunction: (T) -> () { return generic } var genericFunctionTwo: (T, T) -> () { return genericTwo } var genericFunctionTuple: ((T, T)) -> () { return genericTuple } } do { let s = Generic() s.genericFunction(3.0) s.genericFunction((3.0)) s.genericFunctionTwo(3.0, 4.0) s.genericFunctionTwo((3.0, 4.0)) // expected-error {{missing argument for parameter #2 in call}} s.genericFunctionTuple(3.0, 4.0) // expected-error {{single parameter of type '(Double, Double)' is expected in call}} {{26-26=(}} {{34-34=)}} s.genericFunctionTuple((3.0, 4.0)) let sTwo = Generic<(Double, Double)>() sTwo.genericFunction(3.0, 4.0) sTwo.genericFunction((3.0, 4.0)) // Does not diagnose in Swift 3 mode } do { let s = Generic() let a = 3.0 let b = 4.0 let c = (3.0) let d = (a, b) s.genericFunction(a) s.genericFunction((a)) s.genericFunction(c) s.genericFunctionTwo(a, b) s.genericFunctionTwo((a, b)) s.genericFunctionTuple(a, b) s.genericFunctionTuple((a, b)) let sTwo = Generic<(Double, Double)>() sTwo.genericFunction(a, b) sTwo.genericFunction((a, b)) sTwo.genericFunction(d) // Does not diagnose in Swift 3 mode } do { var s = Generic() var a = 3.0 var b = 4.0 var c = (3.0) var d = (a, b) s.genericFunction(a) s.genericFunction((a)) s.genericFunction(c) s.genericFunctionTwo(a, b) s.genericFunctionTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.genericFunctionTuple(a, b) // expected-error {{single parameter of type '(Double, Double)' is expected in call}} {{26-26=(}} {{30-30=)}} s.genericFunctionTuple((a, b)) var sTwo = Generic<(Double, Double)>() sTwo.genericFunction(a, b) sTwo.genericFunction((a, b)) // Does not diagnose in Swift 3 mode sTwo.genericFunction(d) // Does not diagnose in Swift 3 mode } struct GenericInit { // expected-note 2 {{'T' declared as parameter to type 'GenericInit'}} init(_ x: T) {} } struct GenericInitLabeled { init(x: T) {} } struct GenericInitTwo { init(_ x: T, _ y: T) {} // expected-note 8 {{'init' declared here}} } struct GenericInitTuple { init(_ x: (T, T)) {} } struct GenericInitLabeledTuple { init(x: (T, T)) {} } do { _ = GenericInit(3, 4) _ = GenericInit((3, 4)) _ = GenericInitLabeled(x: 3, 4) // expected-error {{extra argument in call}} _ = GenericInitLabeled(x: (3, 4)) _ = GenericInitTwo(3, 4) _ = GenericInitTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTuple(3, 4) // expected-error {{initializer expects a single parameter of type '(T, T)'}} {{24-24=(}} {{28-28=)}} _ = GenericInitTuple((3, 4)) _ = GenericInitLabeledTuple(x: 3, 4) // expected-error {{initializer expects a single parameter of type '(T, T)'}} _ = GenericInitLabeledTuple(x: (3, 4)) } do { _ = GenericInit<(Int, Int)>(3, 4) _ = GenericInit<(Int, Int)>((3, 4)) // expected-error {{expression type 'GenericInit<(Int, Int)>' is ambiguous without more context}} _ = GenericInitLabeled<(Int, Int)>(x: 3, 4) // expected-error {{extra argument in call}} _ = GenericInitLabeled<(Int, Int)>(x: (3, 4)) _ = GenericInitTwo(3, 4) _ = GenericInitTwo((3, 4)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTuple(3, 4) // expected-error {{initializer expects a single parameter of type '(T, T)'}} {{29-29=(}} {{33-33=)}} _ = GenericInitTuple((3, 4)) _ = GenericInitLabeledTuple(x: 3, 4) // expected-error {{initializer expects a single parameter of type '(T, T)'}} _ = GenericInitLabeledTuple(x: (3, 4)) } do { let a = 3 let b = 4 let c = (a, b) _ = GenericInit(a, b) _ = GenericInit((a, b)) _ = GenericInit(c) _ = GenericInitTwo(a, b) _ = GenericInitTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTwo(c) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTuple(a, b) // expected-error {{initializer expects a single parameter of type '(T, T)'}} {{24-24=(}} {{28-28=)}} _ = GenericInitTuple((a, b)) _ = GenericInitTuple(c) } do { let a = 3 let b = 4 let c = (a, b) _ = GenericInit<(Int, Int)>(a, b) _ = GenericInit<(Int, Int)>((a, b)) _ = GenericInit<(Int, Int)>(c) _ = GenericInitTwo(a, b) _ = GenericInitTwo((a, b)) // Does not diagnose in Swift 3 mode _ = GenericInitTwo(c) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} _ = GenericInitTuple(a, b) // Does not diagnose in Swift 3 mode _ = GenericInitTuple((a, b)) _ = GenericInitTuple(c) } do { var a = 3 var b = 4 var c = (a, b) _ = GenericInit(a, b) // expected-error {{extra argument in call}} _ = GenericInit((a, b)) // expected-error {{generic parameter 'T' could not be inferred}} // expected-note {{explicitly specify the generic arguments to fix this issue}} _ = GenericInit(c) // expected-error {{generic parameter 'T' could not be inferred}} // expected-note {{explicitly specify the generic arguments to fix this issue}} _ = GenericInitTwo(a, b) _ = GenericInitTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTwo(c) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTuple(a, b) // expected-error {{initializer expects a single parameter of type '(T, T)'}} {{24-24=(}} {{28-28=)}} _ = GenericInitTuple((a, b)) _ = GenericInitTuple(c) } do { var a = 3 var b = 4 var c = (a, b) // _ = GenericInit<(Int, Int)>(a, b) // Crashes in Swift 3 _ = GenericInit<(Int, Int)>((a, b)) // expected-error {{expression type 'GenericInit<(Int, Int)>' is ambiguous without more context}} _ = GenericInit<(Int, Int)>(c) // expected-error {{expression type 'GenericInit<(Int, Int)>' is ambiguous without more context}} _ = GenericInitTwo(a, b) _ = GenericInitTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTwo(c) // expected-error {{missing argument for parameter #2 in call}} _ = GenericInitTuple(a, b) // expected-error {{initializer expects a single parameter of type '(T, T)'}} {{29-29=(}} {{33-33=)}} _ = GenericInitTuple((a, b)) _ = GenericInitTuple(c) } struct GenericSubscript { // TODO: Restore regressed diagnostics rdar://problem/31724211 subscript(_ x: T) -> Int { get { return 0 } set { } } // expected-note* {{}} } struct GenericSubscriptLabeled { subscript(x x: T) -> Int { get { return 0 } set { } } } struct GenericSubscriptTwo { subscript(_ x: T, _ y: T) -> Int { get { return 0 } set { } } // expected-note 3 {{'subscript' declared here}} } struct GenericSubscriptTuple { subscript(_ x: (T, T)) -> Int { get { return 0 } set { } } } struct GenericSubscriptLabeledTuple { subscript(x x: (T, T)) -> Int { get { return 0 } set { } } } do { let s1 = GenericSubscript<(Double, Double)>() _ = s1[3.0, 4.0] // TODO: Restore regressed diagnostics rdar://problem/31724211 _ = s1[(3.0, 4.0)] // expected-error {{}} let s1a = GenericSubscriptLabeled<(Double, Double)>() _ = s1a [x: 3.0, 4.0] // expected-error {{extra argument in call}} _ = s1a [x: (3.0, 4.0)] let s2 = GenericSubscriptTwo() _ = s2[3.0, 4.0] _ = s2[(3.0, 4.0)] // expected-error {{missing argument for parameter #2 in call}} let s3 = GenericSubscriptTuple() _ = s3[3.0, 4.0] // expected-error {{subscript expects a single parameter of type '(T, T)'}} {{10-10=(}} {{18-18=)}} _ = s3[(3.0, 4.0)] let s3a = GenericSubscriptLabeledTuple() _ = s3a[x: 3.0, 4.0] // expected-error {{subscript expects a single parameter of type '(T, T)'}} _ = s3a[x: (3.0, 4.0)] } do { let a = 3.0 let b = 4.0 let d = (a, b) let s1 = GenericSubscript<(Double, Double)>() _ = s1[a, b] _ = s1[(a, b)] _ = s1[d] let s2 = GenericSubscriptTwo() _ = s2[a, b] _ = s2[(a, b)] // Does not diagnose in Swift 3 mode _ = s2[d] // Does not diagnose in Swift 3 mode let s3 = GenericSubscriptTuple() _ = s3[a, b] // Does not diagnose in Swift 3 mode _ = s3[(a, b)] _ = s3[d] } do { // TODO: Restore regressed diagnostics rdar://problem/31724211 var a = 3.0 var b = 4.0 var d = (a, b) var s1 = GenericSubscript<(Double, Double)>() _ = s1[a, b] // TODO: Restore regressed diagnostics rdar://problem/31724211 // These two lines give different regressed behavior in S3 and S4 mode // _ = s1[(a, b)] // e/xpected-error {{expression type '@lvalue Int' is ambiguous without more context}} // _ = s1[d] // e/xpected-error {{expression type '@lvalue Int' is ambiguous without more context}} var s2 = GenericSubscriptTwo() _ = s2[a, b] _ = s2[(a, b)] // expected-error {{missing argument for parameter #2 in call}} _ = s2[d] // expected-error {{missing argument for parameter #2 in call}} var s3 = GenericSubscriptTuple() _ = s3[a, b] // expected-error {{subscript expects a single parameter of type '(T, T)'}} {{10-10=(}} {{14-14=)}} _ = s3[(a, b)] _ = s3[d] } enum GenericEnum { case one(T) case labeled(x: T) case two(T, T) // expected-note 8 {{'two' declared here}} case tuple((T, T)) } do { _ = GenericEnum.one(3, 4) _ = GenericEnum.one((3, 4)) _ = GenericEnum.labeled(x: 3, 4) // expected-error {{extra argument in call}} _ = GenericEnum.labeled(x: (3, 4)) _ = GenericEnum.labeled(3, 4) // expected-error {{extra argument in call}} _ = GenericEnum.labeled((3, 4)) // expected-error {{missing argument label 'x:' in call}} _ = GenericEnum.two(3, 4) _ = GenericEnum.two((3, 4)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.tuple(3, 4) // expected-error {{enum element 'tuple' expects a single parameter of type '(T, T)'}} {{25-25=(}} {{29-29=)}} _ = GenericEnum.tuple((3, 4)) } do { _ = GenericEnum<(Int, Int)>.one(3, 4) _ = GenericEnum<(Int, Int)>.one((3, 4)) // Does not diagnose in Swift 3 mode _ = GenericEnum<(Int, Int)>.labeled(x: 3, 4) // expected-error {{enum element 'labeled' expects a single parameter of type '(Int, Int)'}} _ = GenericEnum<(Int, Int)>.labeled(x: (3, 4)) _ = GenericEnum<(Int, Int)>.labeled(3, 4) // expected-error {{enum element 'labeled' expects a single parameter of type '(Int, Int)'}} _ = GenericEnum<(Int, Int)>.labeled((3, 4)) // expected-error {{missing argument label 'x:' in call}} _ = GenericEnum.two(3, 4) _ = GenericEnum.two((3, 4)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.tuple(3, 4) // expected-error {{enum element 'tuple' expects a single parameter of type '(Int, Int)'}} {{30-30=(}} {{34-34=)}} _ = GenericEnum.tuple((3, 4)) } do { let a = 3 let b = 4 let c = (a, b) _ = GenericEnum.one(a, b) _ = GenericEnum.one((a, b)) _ = GenericEnum.one(c) _ = GenericEnum.two(a, b) _ = GenericEnum.two((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.two(c) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.tuple(a, b) // expected-error {{enum element 'tuple' expects a single parameter of type '(T, T)'}} {{25-25=(}} {{29-29=)}} _ = GenericEnum.tuple((a, b)) _ = GenericEnum.tuple(c) } do { let a = 3 let b = 4 let c = (a, b) _ = GenericEnum<(Int, Int)>.one(a, b) _ = GenericEnum<(Int, Int)>.one((a, b)) _ = GenericEnum<(Int, Int)>.one(c) _ = GenericEnum.two(a, b) _ = GenericEnum.two((a, b)) _ = GenericEnum.two(c) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} _ = GenericEnum.tuple(a, b) _ = GenericEnum.tuple((a, b)) _ = GenericEnum.tuple(c) } do { var a = 3 var b = 4 var c = (a, b) // _ = GenericEnum.one(a, b) // Crashes in actual Swift 3 _ = GenericEnum.one((a, b)) // Does not diagnose in Swift 3 mode _ = GenericEnum.one(c) // Does not diagnose in Swift 3 mode _ = GenericEnum.two(a, b) _ = GenericEnum.two((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.two(c) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.tuple(a, b) // expected-error {{enum element 'tuple' expects a single parameter of type '(T, T)'}} {{25-25=(}} {{29-29=)}} _ = GenericEnum.tuple((a, b)) _ = GenericEnum.tuple(c) } do { var a = 3 var b = 4 var c = (a, b) // _ = GenericEnum<(Int, Int)>.one(a, b) // Crashes in actual Swift 3 _ = GenericEnum<(Int, Int)>.one((a, b)) // Does not diagnose in Swift 3 mode _ = GenericEnum<(Int, Int)>.one(c) // Does not diagnose in Swift 3 mode _ = GenericEnum.two(a, b) _ = GenericEnum.two((a, b)) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.two(c) // expected-error {{missing argument for parameter #2 in call}} _ = GenericEnum.tuple(a, b) // expected-error {{enum element 'tuple' expects a single parameter of type '(Int, Int)'}} {{30-30=(}} {{34-34=)}} _ = GenericEnum.tuple((a, b)) _ = GenericEnum.tuple(c) } protocol Protocol { associatedtype Element } extension Protocol { func requirement(_ x: Element) {} func requirementLabeled(x: Element) {} func requirementTwo(_ x: Element, _ y: Element) {} // expected-note 2 {{'requirementTwo' declared here}} func requirementTuple(_ x: (Element, Element)) {} } struct GenericConforms : Protocol { typealias Element = T } do { let s = GenericConforms() s.requirement(3.0) s.requirement((3.0)) s.requirementLabeled(x: 3.0) s.requirementLabeled(x: (3.0)) s.requirementTwo(3.0, 4.0) s.requirementTwo((3.0, 4.0)) // expected-error {{missing argument for parameter #2 in call}} s.requirementTuple(3.0, 4.0) // expected-error {{instance method 'requirementTuple' expects a single parameter of type '(Double, Double)'}} {{22-22=(}} {{30-30=)}} s.requirementTuple((3.0, 4.0)) let sTwo = GenericConforms<(Double, Double)>() sTwo.requirement(3.0, 4.0) // expected-error {{instance method 'requirement' expects a single parameter of type '(Double, Double)'}} {{20-20=(}} {{28-28=)}} sTwo.requirement((3.0, 4.0)) sTwo.requirementLabeled(x: 3.0, 4.0) // expected-error {{instance method 'requirementLabeled' expects a single parameter of type '(Double, Double)'}} sTwo.requirementLabeled(x: (3.0, 4.0)) } do { let s = GenericConforms() let a = 3.0 let b = 4.0 let c = (3.0) let d = (a, b) s.requirement(a) s.requirement((a)) s.requirement(c) s.requirementTwo(a, b) s.requirementTwo((a, b)) // Does not diagnose in Swift 3 mode s.requirementTuple(a, b) // Does not diagnose in Swift 3 mode s.requirementTuple((a, b)) let sTwo = GenericConforms<(Double, Double)>() sTwo.requirement(a, b) sTwo.requirement((a, b)) sTwo.requirement(d) } do { var s = GenericConforms() var a = 3.0 var b = 4.0 var c = (3.0) var d = (a, b) s.requirement(a) s.requirement((a)) s.requirement(c) s.requirementTwo(a, b) s.requirementTwo((a, b)) // expected-error {{missing argument for parameter #2 in call}} s.requirementTuple(a, b) // expected-error {{instance method 'requirementTuple' expects a single parameter of type '(Double, Double)'}} {{22-22=(}} {{26-26=)}} s.requirementTuple((a, b)) var sTwo = GenericConforms<(Double, Double)>() sTwo.requirement(a, b) // expected-error {{instance method 'requirement' expects a single parameter of type '(Double, Double)'}} {{20-20=(}} {{24-24=)}} sTwo.requirement((a, b)) sTwo.requirement(d) } extension Protocol { func takesClosure(_ fn: (Element) -> ()) {} func takesClosureTwo(_ fn: (Element, Element) -> ()) {} func takesClosureTuple(_ fn: ((Element, Element)) -> ()) {} } do { let s = GenericConforms() s.takesClosure({ _ = $0 }) s.takesClosure({ x in }) s.takesClosure({ (x: Double) in }) s.takesClosureTwo({ _ = $0 }) s.takesClosureTwo({ x in }) s.takesClosureTwo({ (x: (Double, Double)) in }) s.takesClosureTwo({ _ = $0; _ = $1 }) s.takesClosureTwo({ (x, y) in }) s.takesClosureTwo({ (x: Double, y:Double) in }) s.takesClosureTuple({ _ = $0 }) s.takesClosureTuple({ x in }) s.takesClosureTuple({ (x: (Double, Double)) in }) s.takesClosureTuple({ _ = $0; _ = $1 }) s.takesClosureTuple({ (x, y) in }) s.takesClosureTuple({ (x: Double, y:Double) in }) let sTwo = GenericConforms<(Double, Double)>() sTwo.takesClosure({ _ = $0 }) sTwo.takesClosure({ x in }) sTwo.takesClosure({ (x: (Double, Double)) in }) sTwo.takesClosure({ _ = $0; _ = $1 }) sTwo.takesClosure({ (x, y) in }) sTwo.takesClosure({ (x: Double, y: Double) in }) } do { let _: ((Int, Int)) -> () = { _ = $0 } let _: ((Int, Int)) -> () = { _ = ($0.0, $0.1) } let _: ((Int, Int)) -> () = { t in _ = (t.0, t.1) } let _: ((Int, Int)) -> () = { _ = ($0, $1) } let _: ((Int, Int)) -> () = { t, u in _ = (t, u) } let _: (Int, Int) -> () = { _ = $0 } let _: (Int, Int) -> () = { _ = ($0.0, $0.1) } let _: (Int, Int) -> () = { t in _ = (t.0, t.1) } let _: (Int, Int) -> () = { _ = ($0, $1) } let _: (Int, Int) -> () = { t, u in _ = (t, u) } } // rdar://problem/28952837 - argument labels ignored when calling function // with single 'Any' parameter func takesAny(_: Any) {} enum HasAnyCase { case any(_: Any) } do { let fn: (Any) -> () = { _ in } fn(123) fn(data: 123) takesAny(123) takesAny(data: 123) _ = HasAnyCase.any(123) _ = HasAnyCase.any(data: 123) } // rdar://problem/29739905 - protocol extension methods on Array had // ParenType sugar stripped off the element type typealias BoolPair = (Bool, Bool) func processArrayOfFunctions(f1: [((Bool, Bool)) -> ()], f2: [(Bool, Bool) -> ()], c: Bool) { let p = (c, c) f1.forEach { block in block(p) block((c, c)) block(c, c) } f2.forEach { block in block(p) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} block((c, c)) block(c, c) } f2.forEach { (block: ((Bool, Bool)) -> ()) in block(p) block((c, c)) block(c, c) } f2.forEach { (block: (Bool, Bool) -> ()) in block(p) // expected-error {{passing 2 arguments to a callee as a single tuple value has been removed in Swift 3}} block((c, c)) block(c, c) } } // expected-error@+1 {{cannot create a single-element tuple with an element label}} func singleElementTupleArgument(completion: ((didAdjust: Bool)) -> Void) { // TODO: Error could be improved. // expected-error@+1 {{cannot convert value of type '(didAdjust: Bool)' to expected argument type 'Bool'}} completion((didAdjust: true)) } // SR-4378 -- FIXME -- this should type check, it used to work in Swift 3.0 final public class MutableProperty { public init(_ initialValue: Value) {} } enum DataSourcePage { case notLoaded } let pages1: MutableProperty<(data: DataSourcePage, totalCount: Int)> = MutableProperty(( // expected-error@-1 {{expression type 'MutableProperty<(data: DataSourcePage, totalCount: Int)>' is ambiguous without more context}} data: .notLoaded, totalCount: 0 )) let pages2: MutableProperty<(data: DataSourcePage, totalCount: Int)> = MutableProperty(( // expected-error@-1 {{cannot convert value of type 'MutableProperty<(data: DataSourcePage<_>, totalCount: Int)>' to specified type 'MutableProperty<(data: DataSourcePage, totalCount: Int)>'}} data: DataSourcePage.notLoaded, totalCount: 0 )) let pages3: MutableProperty<(data: DataSourcePage, totalCount: Int)> = MutableProperty(( // expected-error@-1 {{expression type 'MutableProperty<(data: DataSourcePage, totalCount: Int)>' is ambiguous without more context}} data: DataSourcePage.notLoaded, totalCount: 0 )) // rdar://problem/32301091 - Make sure that in Swift 3 mode following expressions still compile just fine func rdar32301091_1(_ :((Int, Int) -> ())!) {} rdar32301091_1 { _ in } // Ok in Swift 3 func rdar32301091_2(_ :(Int, Int) -> ()) {} rdar32301091_2 { _ in } // Ok in Swift 3 // rdar://problem/35198459 - source-compat-suite failure: Moya (toType->hasUnresolvedType() && "Should have handled this above") do { func foo(_: (() -> Void)?) {} func bar() -> ((()) -> Void)? { return nil } foo(bar()) // OK in Swift 3 mode } // https://bugs.swift.org/browse/SR-6509 public extension Optional { public func apply(_ transform: ((Wrapped) -> Result)?) -> Result? { return self.flatMap { value in transform.map { $0(value) } } } public func apply(_ value: Value?) -> Result? where Wrapped == (Value) -> Result { return value.apply(self) } } // https://bugs.swift.org/browse/SR-6837 do { func takeFn(fn: (_ i: Int, _ j: Int?) -> ()) {} func takePair(_ pair: (Int, Int?)) {} takeFn(fn: takePair) takeFn(fn: { (pair: (Int, Int?)) in } ) takeFn { (pair: (Int, Int?)) in } } // https://bugs.swift.org/browse/SR-6796 do { func f(a: (() -> Void)? = nil) {} func log() -> ((T) -> Void)? { return nil } f(a: log() as ((()) -> Void)?) // Allow ((()) -> Void)? to be passed in place of (() -> Void)? func logNoOptional() -> (T) -> Void { } f(a: logNoOptional() as ((()) -> Void)) // Also allow the optional-injected form. func g() {} g(()) func h(_: ()) {} h() }