test/SILGen/constrained_extensions.swift - third_party/swift - Git at Google


 // RUN: %target-swift-emit-silgen -module-name constrained_extensions -primary-file %s | %FileCheck %s
 // RUN: %target-swift-emit-sil -module-name constrained_extensions -O -primary-file %s > /dev/null
 // RUN: %target-swift-emit-ir -module-name constrained_extensions -primary-file %s > /dev/null

 extension Array where Element == Int {
   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE1xSaySiGyt_tcfC : $@convention(method) (@thin Array<Int>.Type) -> @owned Array<Int>
   public init(x: ()) {
     self.init()
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE16instancePropertySivg : $@convention(method) (@guaranteed Array<Int>) -> Int
   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE16instancePropertySivs : $@convention(method) (Int, @inout Array<Int>) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] [ossa] @$sSa22constrained_extensionsSiRszlE16instancePropertySivM : $@yield_once @convention(method) (@inout Array<Int>) -> @yields @inout Int

   public var instanceProperty: Element {
     get {
       return self[0]
     }
     set {
       self[0] = newValue
     }
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE14instanceMethodSiyF : $@convention(method) (@guaranteed Array<Int>) -> Int
   public func instanceMethod() -> Element {
     return instanceProperty
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE14instanceMethod1eS2i_tF : $@convention(method) (Int, @guaranteed Array<Int>) -> Int
   public func instanceMethod(e: Element) -> Element {
     return e
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE14staticPropertySivgZ : $@convention(method) (@thin Array<Int>.Type) -> Int
   public static var staticProperty: Element {
     return Array(x: ()).instanceProperty
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE12staticMethodSiyFZ : $@convention(method) (@thin Array<Int>.Type) -> Int
   public static func staticMethod() -> Element {
     return staticProperty
   }

   // CHECK-LABEL: sil non_abi [serialized] [ossa] @$sSa22constrained_extensionsSiRszlE12staticMethod1eS2iSg_tFZfA_ : $@convention(thin) () -> Optional<Int>
   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE12staticMethod1eS2iSg_tFZ : $@convention(method) (Optional<Int>, @thin Array<Int>.Type) -> Int
   public static func staticMethod(e: Element? = nil) -> Element {
     return e!
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlEySiyt_tcig : $@convention(method) (@guaranteed Array<Int>) -> Int
   public subscript(i: ()) -> Element {
     return self[0]
   }

   // CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE21inoutAccessOfPropertyyyF : $@convention(method) (@inout Array<Int>) -> ()
   public mutating func inoutAccessOfProperty() {
     func increment(x: inout Element) {
       x += 1
     }

     increment(x: &instanceProperty)
   }
 }

 extension Dictionary where Key == Int {
   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE1xSDySiq_Gyt_tcfC : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> @owned Dictionary<Int, Value> {
   public init(x: ()) {
     self.init()
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE16instancePropertyq_vg : $@convention(method) <Key, Value where Key == Int> (@guaranteed Dictionary<Int, Value>) -> @out Value
   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE16instancePropertyq_vs : $@convention(method) <Key, Value where Key == Int> (@in Value, @inout Dictionary<Int, Value>) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] [ossa] @$sSD22constrained_extensionsSiRszrlE16instancePropertyq_vM : $@yield_once @convention(method) <Key, Value where Key == Int> (@inout Dictionary<Int, Value>) -> @yields @inout Value
   public var instanceProperty: Value {
     get {
       return self[0]!
     }
     set {
       self[0] = newValue
     }
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE14instanceMethodq_yF : $@convention(method) <Key, Value where Key == Int> (@guaranteed Dictionary<Int, Value>) -> @out Value
   public func instanceMethod() -> Value {
     return instanceProperty
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE14instanceMethod1vq_q__tF : $@convention(method) <Key, Value where Key == Int> (@in_guaranteed Value, @guaranteed Dictionary<Int, Value>) -> @out Value
   public func instanceMethod(v: Value) -> Value {
     return v
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethodSiyFZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> Int
   public static func staticMethod() -> Key {
     return staticProperty
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE14staticPropertySivgZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> Int
   public static var staticProperty: Key {
     return 0
   }

   // CHECK-LABEL: sil non_abi [serialized] [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethod1k1vq_SiSg_q_SgtFZfA_ : $@convention(thin) <Key, Value where Key == Int> () -> Optional<Int>
   // CHECK-LABEL: sil non_abi [serialized] [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethod1k1vq_SiSg_q_SgtFZfA0_ : $@convention(thin) <Key, Value where Key == Int> () -> @out Optional<Value>
   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethod1k1vq_SiSg_q_SgtFZ : $@convention(method) <Key, Value where Key == Int> (Optional<Int>, @in_guaranteed Optional<Value>, @thin Dictionary<Int, Value>.Type) -> @out Value
   public static func staticMethod(k: Key? = nil, v: Value? = nil) -> Value {
     return v!
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE17callsStaticMethodq_yFZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> @out Value
   public static func callsStaticMethod() -> Value {
     return staticMethod()
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE16callsConstructorq_yFZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> @out Value
   public static func callsConstructor() -> Value {
     return Dictionary(x: ()).instanceMethod()
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlEyq_yt_tcig : $@convention(method) <Key, Value where Key == Int> (@guaranteed Dictionary<Int, Value>) -> @out Value
   public subscript(i: ()) -> Value {
     return self[0]!
   }

   // CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE21inoutAccessOfPropertyyyF : $@convention(method) <Key, Value where Key == Int> (@inout Dictionary<Int, Value>) -> ()
   public mutating func inoutAccessOfProperty() {
     func increment(x: inout Value) { }

     increment(x: &instanceProperty)
   }
 }

 public class GenericClass<X, Y> {}

 extension GenericClass where Y == () {
   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5valuexvg : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @out X
   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5valuexvs : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5valuexvM : $@yield_once @convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @yields @inout X
   public var value: X {
     get { while true {} }
     set {}
   }

   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvg : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvs : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvM : $@yield_once @convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) ->  @yields @inout ()
   public var empty: Y {
     get { return () }
     set {}
   }

   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcig : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @out X
   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcis : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tciM : $@yield_once @convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) ->  @yields @inout X
   public subscript(_: Y) -> X {
     get { while true {} }
     set {}
   }

   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyyxcig : $@convention(method) <X, Y where Y == ()> (@in_guaranteed X, @guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyyxcis : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyyxciM : $@yield_once @convention(method) <X, Y where Y == ()> (@in_guaranteed X, @guaranteed GenericClass<X, ()>) ->  @yields @inout ()
   public subscript(_: X) -> Y {
     get { while true {} }
     set {}
   }
 }

 protocol VeryConstrained {}

 struct AnythingGoes<T> {
   // CHECK-LABEL: sil hidden [transparent] [ossa] @$s22constrained_extensions12AnythingGoesV13meaningOfLifexSgvpfi : $@convention(thin) <T> () -> @out Optional<T>
   var meaningOfLife: T? = nil
 }

 extension AnythingGoes where T : VeryConstrained {
   // CHECK-LABEL: sil hidden [ossa] @$s22constrained_extensions12AnythingGoesVA2A15VeryConstrainedRzlE13fromExtensionACyxGyt_tcfC : $@convention(method) <T where T : VeryConstrained> (@thin AnythingGoes<T>.Type) -> @out AnythingGoes<T> {

   // CHECK: [[INIT:%.*]] = function_ref @$s22constrained_extensions12AnythingGoesV13meaningOfLifexSgvpfi : $@convention(thin) <τ_0_0> () -> @out Optional<τ_0_0>
   // CHECK: [[RESULT:%.*]] = alloc_stack $Optional<T>
   // CHECK: apply [[INIT]]<T>([[RESULT]]) : $@convention(thin) <τ_0_0> () -> @out Optional<τ_0_0>
   // CHECK: return
   init(fromExtension: ()) {}
 }

 extension Array where Element == Int {
   struct Nested {
     // CHECK-LABEL: sil hidden [transparent] [ossa] @$sSa22constrained_extensionsSiRszlE6NestedV1eSiSgvpfi : $@convention(thin) () -> Optional<Int>
     var e: Element? = nil

     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsSiRszlE6NestedV10hasDefault1eySiSg_tFfA_ : $@convention(thin) () -> Optional<Int>
     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsSiRszlE6NestedV10hasDefault1eySiSg_tF : $@convention(method) (Optional<Int>, @inout Array<Int>.Nested) -> ()
     mutating func hasDefault(e: Element? = nil) {
       self.e = e
     }
   }
 }

 extension Array where Element == AnyObject {
   class NestedClass {
     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCfd : $@convention(method) (@guaranteed Array<AnyObject>.NestedClass) -> @owned Builtin.NativeObject
     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCfD : $@convention(method) (@owned Array<AnyObject>.NestedClass) -> ()
     deinit { }

     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCACyyXl_GycfC : $@convention(method) (@thick Array<AnyObject>.NestedClass.Type) -> @owned Array<AnyObject>.NestedClass
     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCACyyXl_Gycfc : $@convention(method) (@owned Array<AnyObject>.NestedClass) -> @owned Array<AnyObject>.NestedClass
   }

   class DerivedClass : NestedClass {
     // CHECK-LABEL: sil hidden [transparent] [ossa] @$sSa22constrained_extensionsyXlRszlE12DerivedClassC1eyXlSgvpfi : $@convention(thin) () -> @owned Optional<AnyObject>
     // CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE12DerivedClassCfE : $@convention(method) (@guaranteed Array<AnyObject>.DerivedClass) -> ()
     var e: Element? = nil
   }

   enum NestedEnum {
     case hay
     case grain

     func makeHay() -> NestedEnum {
       return .hay
     }
   }
 }

 func referenceNestedTypes() {
   _ = Array<AnyObject>.NestedClass()
   _ = Array<AnyObject>.DerivedClass()
 }

	// RUN: %target-swift-emit-silgen -module-name constrained_extensions -primary-file %s \| %FileCheck %s
	// RUN: %target-swift-emit-sil -module-name constrained_extensions -O -primary-file %s > /dev/null
	// RUN: %target-swift-emit-ir -module-name constrained_extensions -primary-file %s > /dev/null

	extension Array where Element == Int {
	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE1xSaySiGyt_tcfC : $@convention(method) (@thin Array<Int>.Type) -> @owned Array<Int>
	public init(x: ()) {
	self.init()
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE16instancePropertySivg : $@convention(method) (@guaranteed Array<Int>) -> Int
	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE16instancePropertySivs : $@convention(method) (Int, @inout Array<Int>) -> ()
	// CHECK-LABEL: sil [transparent] [serialized] [ossa] @$sSa22constrained_extensionsSiRszlE16instancePropertySivM : $@yield_once @convention(method) (@inout Array<Int>) -> @yields @inout Int

	public var instanceProperty: Element {
	get {
	return self[0]
	}
	set {
	self[0] = newValue
	}
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE14instanceMethodSiyF : $@convention(method) (@guaranteed Array<Int>) -> Int
	public func instanceMethod() -> Element {
	return instanceProperty
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE14instanceMethod1eS2i_tF : $@convention(method) (Int, @guaranteed Array<Int>) -> Int
	public func instanceMethod(e: Element) -> Element {
	return e
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE14staticPropertySivgZ : $@convention(method) (@thin Array<Int>.Type) -> Int
	public static var staticProperty: Element {
	return Array(x: ()).instanceProperty
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE12staticMethodSiyFZ : $@convention(method) (@thin Array<Int>.Type) -> Int
	public static func staticMethod() -> Element {
	return staticProperty
	}

	// CHECK-LABEL: sil non_abi [serialized] [ossa] @$sSa22constrained_extensionsSiRszlE12staticMethod1eS2iSg_tFZfA_ : $@convention(thin) () -> Optional<Int>
	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE12staticMethod1eS2iSg_tFZ : $@convention(method) (Optional<Int>, @thin Array<Int>.Type) -> Int
	public static func staticMethod(e: Element? = nil) -> Element {
	return e!
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlEySiyt_tcig : $@convention(method) (@guaranteed Array<Int>) -> Int
	public subscript(i: ()) -> Element {
	return self[0]
	}

	// CHECK-LABEL: sil [ossa] @$sSa22constrained_extensionsSiRszlE21inoutAccessOfPropertyyyF : $@convention(method) (@inout Array<Int>) -> ()
	public mutating func inoutAccessOfProperty() {
	func increment(x: inout Element) {
	x += 1
	}

	increment(x: &instanceProperty)
	}
	}

	extension Dictionary where Key == Int {
	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE1xSDySiq_Gyt_tcfC : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> @owned Dictionary<Int, Value> {
	public init(x: ()) {
	self.init()
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE16instancePropertyq_vg : $@convention(method) <Key, Value where Key == Int> (@guaranteed Dictionary<Int, Value>) -> @out Value
	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE16instancePropertyq_vs : $@convention(method) <Key, Value where Key == Int> (@in Value, @inout Dictionary<Int, Value>) -> ()
	// CHECK-LABEL: sil [transparent] [serialized] [ossa] @$sSD22constrained_extensionsSiRszrlE16instancePropertyq_vM : $@yield_once @convention(method) <Key, Value where Key == Int> (@inout Dictionary<Int, Value>) -> @yields @inout Value
	public var instanceProperty: Value {
	get {
	return self[0]!
	}
	set {
	self[0] = newValue
	}
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE14instanceMethodq_yF : $@convention(method) <Key, Value where Key == Int> (@guaranteed Dictionary<Int, Value>) -> @out Value
	public func instanceMethod() -> Value {
	return instanceProperty
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE14instanceMethod1vq_q__tF : $@convention(method) <Key, Value where Key == Int> (@in_guaranteed Value, @guaranteed Dictionary<Int, Value>) -> @out Value
	public func instanceMethod(v: Value) -> Value {
	return v
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethodSiyFZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> Int
	public static func staticMethod() -> Key {
	return staticProperty
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE14staticPropertySivgZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> Int
	public static var staticProperty: Key {
	return 0
	}

	// CHECK-LABEL: sil non_abi [serialized] [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethod1k1vq_SiSg_q_SgtFZfA_ : $@convention(thin) <Key, Value where Key == Int> () -> Optional<Int>
	// CHECK-LABEL: sil non_abi [serialized] [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethod1k1vq_SiSg_q_SgtFZfA0_ : $@convention(thin) <Key, Value where Key == Int> () -> @out Optional<Value>
	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE12staticMethod1k1vq_SiSg_q_SgtFZ : $@convention(method) <Key, Value where Key == Int> (Optional<Int>, @in_guaranteed Optional<Value>, @thin Dictionary<Int, Value>.Type) -> @out Value
	public static func staticMethod(k: Key? = nil, v: Value? = nil) -> Value {
	return v!
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE17callsStaticMethodq_yFZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> @out Value
	public static func callsStaticMethod() -> Value {
	return staticMethod()
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE16callsConstructorq_yFZ : $@convention(method) <Key, Value where Key == Int> (@thin Dictionary<Int, Value>.Type) -> @out Value
	public static func callsConstructor() -> Value {
	return Dictionary(x: ()).instanceMethod()
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlEyq_yt_tcig : $@convention(method) <Key, Value where Key == Int> (@guaranteed Dictionary<Int, Value>) -> @out Value
	public subscript(i: ()) -> Value {
	return self[0]!
	}

	// CHECK-LABEL: sil [ossa] @$sSD22constrained_extensionsSiRszrlE21inoutAccessOfPropertyyyF : $@convention(method) <Key, Value where Key == Int> (@inout Dictionary<Int, Value>) -> ()
	public mutating func inoutAccessOfProperty() {
	func increment(x: inout Value) { }

	increment(x: &instanceProperty)
	}
	}

	public class GenericClass<X, Y> {}

	extension GenericClass where Y == () {
	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5valuexvg : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @out X
	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5valuexvs : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
	// CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5valuexvM : $@yield_once @convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @yields @inout X
	public var value: X {
	get { while true {} }
	set {}
	}

	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvg : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> ()
	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvs : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> ()
	// CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvM : $@yield_once @convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @yields @inout ()
	public var empty: Y {
	get { return () }
	set {}
	}

	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcig : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @out X
	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcis : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
	// CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tciM : $@yield_once @convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @yields @inout X
	public subscript(_: Y) -> X {
	get { while true {} }
	set {}
	}

	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyyxcig : $@convention(method) <X, Y where Y == ()> (@in_guaranteed X, @guaranteed GenericClass<X, ()>) -> ()
	// CHECK-LABEL: sil [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyyxcis : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
	// CHECK-LABEL: sil [transparent] [serialized] [ossa] @$s22constrained_extensions12GenericClassCAAytRs_rlEyyxciM : $@yield_once @convention(method) <X, Y where Y == ()> (@in_guaranteed X, @guaranteed GenericClass<X, ()>) -> @yields @inout ()
	public subscript(_: X) -> Y {
	get { while true {} }
	set {}
	}
	}

	protocol VeryConstrained {}

	struct AnythingGoes<T> {
	// CHECK-LABEL: sil hidden [transparent] [ossa] @$s22constrained_extensions12AnythingGoesV13meaningOfLifexSgvpfi : $@convention(thin) <T> () -> @out Optional<T>
	var meaningOfLife: T? = nil
	}

	extension AnythingGoes where T : VeryConstrained {
	// CHECK-LABEL: sil hidden [ossa] @$s22constrained_extensions12AnythingGoesVA2A15VeryConstrainedRzlE13fromExtensionACyxGyt_tcfC : $@convention(method) <T where T : VeryConstrained> (@thin AnythingGoes<T>.Type) -> @out AnythingGoes<T> {

	// CHECK: [[INIT:%.*]] = function_ref @$s22constrained_extensions12AnythingGoesV13meaningOfLifexSgvpfi : $@convention(thin) <τ_0_0> () -> @out Optional<τ_0_0>
	// CHECK: [[RESULT:%.*]] = alloc_stack $Optional<T>
	// CHECK: apply [[INIT]]<T>([[RESULT]]) : $@convention(thin) <τ_0_0> () -> @out Optional<τ_0_0>
	// CHECK: return
	init(fromExtension: ()) {}
	}

	extension Array where Element == Int {
	struct Nested {
	// CHECK-LABEL: sil hidden [transparent] [ossa] @$sSa22constrained_extensionsSiRszlE6NestedV1eSiSgvpfi : $@convention(thin) () -> Optional<Int>
	var e: Element? = nil

	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsSiRszlE6NestedV10hasDefault1eySiSg_tFfA_ : $@convention(thin) () -> Optional<Int>
	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsSiRszlE6NestedV10hasDefault1eySiSg_tF : $@convention(method) (Optional<Int>, @inout Array<Int>.Nested) -> ()
	mutating func hasDefault(e: Element? = nil) {
	self.e = e
	}
	}
	}

	extension Array where Element == AnyObject {
	class NestedClass {
	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCfd : $@convention(method) (@guaranteed Array<AnyObject>.NestedClass) -> @owned Builtin.NativeObject
	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCfD : $@convention(method) (@owned Array<AnyObject>.NestedClass) -> ()
	deinit { }

	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCACyyXl_GycfC : $@convention(method) (@thick Array<AnyObject>.NestedClass.Type) -> @owned Array<AnyObject>.NestedClass
	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE11NestedClassCACyyXl_Gycfc : $@convention(method) (@owned Array<AnyObject>.NestedClass) -> @owned Array<AnyObject>.NestedClass
	}

	class DerivedClass : NestedClass {
	// CHECK-LABEL: sil hidden [transparent] [ossa] @$sSa22constrained_extensionsyXlRszlE12DerivedClassC1eyXlSgvpfi : $@convention(thin) () -> @owned Optional<AnyObject>
	// CHECK-LABEL: sil hidden [ossa] @$sSa22constrained_extensionsyXlRszlE12DerivedClassCfE : $@convention(method) (@guaranteed Array<AnyObject>.DerivedClass) -> ()
	var e: Element? = nil
	}

	enum NestedEnum {
	case hay
	case grain

	func makeHay() -> NestedEnum {
	return .hay
	}
	}
	}

	func referenceNestedTypes() {
	_ = Array<AnyObject>.NestedClass()
	_ = Array<AnyObject>.DerivedClass()
	}