stdlib/public/SDK/UIKit/UIKit.swift - third_party/swift - Git at Google

 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//

 import Foundation
 @_exported import UIKit

 #if os(iOS) || os(tvOS)
 import _SwiftUIKitOverlayShims
 #endif

 //===----------------------------------------------------------------------===//
 // UIGeometry
 //===----------------------------------------------------------------------===//

 public extension UIEdgeInsets {
   static var zero: UIEdgeInsets {
     @_transparent // @fragile
     get { return UIEdgeInsets(top: 0.0, left: 0.0, bottom: 0.0, right: 0.0) }
   }
 }

 public extension UIOffset {
   static var zero: UIOffset {
     @_transparent // @fragile
     get { return UIOffset(horizontal: 0.0, vertical: 0.0) }
   }
 }

 //===----------------------------------------------------------------------===//
 // Equatable types.
 //===----------------------------------------------------------------------===//

 extension UIEdgeInsets : Equatable {
   @_transparent // @fragile
   public static func == (lhs: UIEdgeInsets, rhs: UIEdgeInsets) -> Bool {
     return lhs.top == rhs.top &&
            lhs.left == rhs.left &&
            lhs.bottom == rhs.bottom &&
            lhs.right == rhs.right
   }
 }

 extension UIOffset : Equatable {
   @_transparent // @fragile
   public static func == (lhs: UIOffset, rhs: UIOffset) -> Bool {
     return lhs.horizontal == rhs.horizontal &&
            lhs.vertical == rhs.vertical
   }
 }

 //===----------------------------------------------------------------------===//
 // Numeric backed types
 //===----------------------------------------------------------------------===//

 @available(swift 4)
 public protocol _UIKitNumericRawRepresentable : RawRepresentable, Comparable where RawValue: Comparable & Numeric {}

 extension _UIKitNumericRawRepresentable {

   public static func <(lhs: Self, rhs: Self) -> Bool {
     return lhs.rawValue < rhs.rawValue
   }

   public static func +(lhs: Self, rhs: RawValue) -> Self {
     return Self(rawValue: lhs.rawValue + rhs)!
   }

   public static func +(lhs: RawValue, rhs: Self) -> Self {
     return Self(rawValue: lhs + rhs.rawValue)!
   }

   public static func -(lhs: Self, rhs: RawValue) -> Self {
     return Self(rawValue: lhs.rawValue - rhs)!
   }

   public static func -(lhs: Self, rhs: Self) -> RawValue {
     return lhs.rawValue - rhs.rawValue
   }

   public static func +=(lhs: inout Self, rhs: RawValue) {
     lhs = Self(rawValue: lhs.rawValue + rhs)!
   }

   public static func -=(lhs: inout Self, rhs: RawValue) {
     lhs = Self(rawValue: lhs.rawValue - rhs)!
   }
 }

 @available(swift 4)
 extension UIFont.Weight : _UIKitNumericRawRepresentable {}

 #if !os(watchOS)
 @available(swift 4)
 extension UILayoutPriority : _UIKitNumericRawRepresentable {}
 #endif

 // These are un-imported macros in UIKit.

 //===----------------------------------------------------------------------===//
 // UIDeviceOrientation
 //===----------------------------------------------------------------------===//

 #if !os(watchOS) && !os(tvOS)
 public extension UIDeviceOrientation {
   var isLandscape: Bool {
     return self == .landscapeLeft || self == .landscapeRight
   }

   var isPortrait: Bool {
     return self == .portrait || self == .portraitUpsideDown
   }

   var isFlat: Bool {
     return self == .faceUp || self == .faceDown
   }

   var isValidInterfaceOrientation: Bool {
     switch self {
     case .portrait, .portraitUpsideDown, .landscapeLeft, .landscapeRight:
       return true
     default:
       return false
     }
   }
 }

 public func UIDeviceOrientationIsLandscape(
   _ orientation: UIDeviceOrientation
 ) -> Bool {
   return orientation.isLandscape
 }

 public func UIDeviceOrientationIsPortrait(
   _ orientation: UIDeviceOrientation
 ) -> Bool {
   return orientation.isPortrait
 }

 public func UIDeviceOrientationIsValidInterfaceOrientation(
   _ orientation: UIDeviceOrientation) -> Bool
 {
   return orientation.isValidInterfaceOrientation
 }
 #endif

 //===----------------------------------------------------------------------===//
 // UIInterfaceOrientation
 //===----------------------------------------------------------------------===//

 #if !os(watchOS) && !os(tvOS)
 public extension UIInterfaceOrientation {
   var isLandscape: Bool {
     return self == .landscapeLeft || self == .landscapeRight
   }

   var isPortrait: Bool {
     return self == .portrait || self == .portraitUpsideDown
   }
 }

 public func UIInterfaceOrientationIsPortrait(
   _ orientation: UIInterfaceOrientation) -> Bool {
   return orientation.isPortrait
 }

 public func UIInterfaceOrientationIsLandscape(
   _ orientation: UIInterfaceOrientation
 ) -> Bool {
   return orientation.isLandscape
 }
 #endif

 // Overlays for variadic initializers.

 #if !os(watchOS) && !os(tvOS)
 public extension UIActionSheet {
   convenience init(title: String?,
        delegate: UIActionSheetDelegate?,
        cancelButtonTitle: String?,
        destructiveButtonTitle: String?,
        // Hack around overload ambiguity with non-variadic constructor.
        // <rdar://problem/16704770>
        otherButtonTitles firstButtonTitle: String,
        _ moreButtonTitles: String...) {
     self.init(title: title,
               delegate: delegate,
               cancelButtonTitle: cancelButtonTitle,
               destructiveButtonTitle: destructiveButtonTitle)
     self.addButton(withTitle: firstButtonTitle)
     for buttonTitle in moreButtonTitles {
       self.addButton(withTitle: buttonTitle)
     }
   }
 }
 #endif

 #if !os(watchOS) && !os(tvOS)
 public extension UIAlertView {
   convenience init(title: String,
        message: String,
        delegate: UIAlertViewDelegate?,
        cancelButtonTitle: String?,
        // Hack around overload ambiguity with non-variadic constructor.
        // <rdar://problem/16704770>
        otherButtonTitles firstButtonTitle: String,
        _ moreButtonTitles: String...) {
     self.init(title: title,
               message: message,
               delegate: delegate,
               cancelButtonTitle: cancelButtonTitle)
     self.addButton(withTitle: firstButtonTitle)
     for buttonTitle in moreButtonTitles {
       self.addButton(withTitle: buttonTitle)
     }
   }
 }
 #endif

 #if !os(watchOS)
 internal struct _UIViewQuickLookState {
   static var views = Set<UIView>()
 }

 extension UIView : _DefaultCustomPlaygroundQuickLookable {
   @available(*, deprecated, message: "UIView._defaultCustomPlaygroundQuickLook will be removed in a future Swift version")
   public var _defaultCustomPlaygroundQuickLook: PlaygroundQuickLook {
     if _UIViewQuickLookState.views.contains(self) {
       return .view(UIImage())
     } else {
       _UIViewQuickLookState.views.insert(self)
       // in case of an empty rectangle abort the logging
       if (bounds.size.width == 0) || (bounds.size.height == 0) {
         return .view(UIImage())
       }

       UIGraphicsBeginImageContextWithOptions(bounds.size, false, 0.0)
       // UIKit is about to update this to be optional, so make it work
       // with both older and newer SDKs. (In this context it should always
       // be present.)
       let ctx: CGContext! = UIGraphicsGetCurrentContext()
       UIColor(white:1.0, alpha:0.0).set()
       ctx.fill(bounds)
       layer.render(in: ctx)

       let image: UIImage! = UIGraphicsGetImageFromCurrentImageContext()

       UIGraphicsEndImageContext()

       _UIViewQuickLookState.views.remove(self)
       return .view(image)
     }
   }
 }
 #endif

 extension UIColor : _ExpressibleByColorLiteral {
   @nonobjc public required convenience init(_colorLiteralRed red: Float,
                                             green: Float,
                                             blue: Float, alpha: Float) {
     self.init(red: CGFloat(red), green: CGFloat(green),
               blue: CGFloat(blue), alpha: CGFloat(alpha))
   }
 }

 public typealias _ColorLiteralType = UIColor

 extension UIImage : _ExpressibleByImageLiteral {
   private convenience init!(failableImageLiteral name: String) {
     self.init(named: name)
   }

   public required convenience init(imageLiteralResourceName name: String) {
     self.init(failableImageLiteral: name)
   }
 }

 public typealias _ImageLiteralType = UIImage

 extension UIFontTextStyle {
     @available(iOS 11.0, watchOS 4.0, tvOS 11.0, *)
     public var metrics: UIFontMetrics {
         return UIFontMetrics(forTextStyle: self)
     }
 }

 #if !os(watchOS) // UIContentSizeCategory not available on watchOS
 extension UIContentSizeCategory {

     @available(iOS 11.0, tvOS 11.0,  *)
     public var isAccessibilityCategory: Bool {
         return __UIContentSizeCategoryIsAccessibilityCategory(self)
     }

     @available(iOS 11.0, tvOS 11.0, *)
     public static func < (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
         return __UIContentSizeCategoryCompareToCategory(left, right) == .orderedAscending
     }

     @available(iOS 11.0, tvOS 11.0, *)
     public static func <= (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
         return __UIContentSizeCategoryCompareToCategory(left, right) != .orderedDescending
     }

     @available(iOS 11.0, tvOS 11.0, *)
     public static func > (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
         return __UIContentSizeCategoryCompareToCategory(left, right) == .orderedDescending
     }

     @available(iOS 11.0, tvOS 11.0, *)
     public static func >= (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
         return __UIContentSizeCategoryCompareToCategory(left, right) != .orderedAscending
     }
 }
 #endif

 //===----------------------------------------------------------------------===//
 // Focus
 //===----------------------------------------------------------------------===//

 #if os(iOS) || os(tvOS)
 @available(iOS 11.0, tvOS 11.0, *)
 extension UIFocusEnvironment {
   @available(iOS 11.0, tvOS 11.0, *)
   public func contains(_ environment: UIFocusEnvironment) -> Bool {
     return _swift_UIKit_UIFocusEnvironmentContainsEnvironment(self, environment)
   }
 }

 @available(iOS 11.0, tvOS 11.0, *)
 extension UIFocusItem {
   @available(iOS 11.0, tvOS 11.0, *)
   public var isFocused: Bool {
     return self === UIScreen.main.focusedItem
   }
 }
 #endif

 //===----------------------------------------------------------------------===//
 // NSItemProviderReading/Writing support
 //===----------------------------------------------------------------------===//

 #if os(iOS)

 @available(iOS 11.0, *)
 extension UIDragDropSession {
   @available(iOS 11.0, *)
   public func canLoadObjects<
     T : _ObjectiveCBridgeable
   >(ofClass: T.Type) -> Bool where T._ObjectiveCType : NSItemProviderReading {
     return self.canLoadObjects(ofClass: T._ObjectiveCType.self);
   }
 }

 @available(iOS 11.0, *)
 extension UIDropSession {
   @available(iOS 11.0, *)
   public func loadObjects<
     T : _ObjectiveCBridgeable
   >(
     ofClass: T.Type,
     completion: @escaping ([T]) -> Void
   ) -> Progress where T._ObjectiveCType : NSItemProviderReading {
     return self.loadObjects(ofClass: T._ObjectiveCType.self) { nss in
       let natives = nss.map { $0 as! T }
       completion(natives)
     }
   }
 }

 @available(iOS 11.0, *)
 extension UIPasteConfiguration {
   @available(iOS 11.0, *)
   public convenience init<
     T : _ObjectiveCBridgeable
   >(forAccepting _: T.Type) where T._ObjectiveCType : NSItemProviderReading {
     self.init(forAccepting: T._ObjectiveCType.self)
   }

   @available(iOS 11.0, *)
   public func addTypeIdentifiers<
     T : _ObjectiveCBridgeable
   >(forAccepting aClass: T.Type)
   where T._ObjectiveCType : NSItemProviderReading {
     self.addTypeIdentifiers(forAccepting: T._ObjectiveCType.self)
   }
 }


 extension UIPasteboard {
   @available(iOS 11.0, *)
   public func setObjects<
     T : _ObjectiveCBridgeable
   >(_ objects: [T]) where T._ObjectiveCType : NSItemProviderWriting {
     // Using a simpler `$0 as! T._ObjectiveCType` triggers and assertion in
     // the compiler.
     self.setObjects(objects.map { $0._bridgeToObjectiveC() })
   }

   @available(iOS 11.0, *)
   public func setObjects<
     T : _ObjectiveCBridgeable
   >(
     _ objects: [T],
     localOnly: Bool,
     expirationDate: Date?
   ) where T._ObjectiveCType : NSItemProviderWriting {
     self.setObjects(
       // Using a simpler `$0 as! T._ObjectiveCType` triggers and assertion in
       // the compiler.
       objects.map { $0._bridgeToObjectiveC() },
       localOnly: localOnly,
       expirationDate: expirationDate)
   }
 }

 #endif
	//===----------------------------------------------------------------------===//
	//
	// 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
	//
	//===----------------------------------------------------------------------===//

	import Foundation
	@_exported import UIKit

	#if os(iOS) \|\| os(tvOS)
	import _SwiftUIKitOverlayShims
	#endif

	//===----------------------------------------------------------------------===//
	// UIGeometry
	//===----------------------------------------------------------------------===//

	public extension UIEdgeInsets {
	static var zero: UIEdgeInsets {
	@_transparent // @fragile
	get { return UIEdgeInsets(top: 0.0, left: 0.0, bottom: 0.0, right: 0.0) }
	}
	}

	public extension UIOffset {
	static var zero: UIOffset {
	@_transparent // @fragile
	get { return UIOffset(horizontal: 0.0, vertical: 0.0) }
	}
	}

	//===----------------------------------------------------------------------===//
	// Equatable types.
	//===----------------------------------------------------------------------===//

	extension UIEdgeInsets : Equatable {
	@_transparent // @fragile
	public static func == (lhs: UIEdgeInsets, rhs: UIEdgeInsets) -> Bool {
	return lhs.top == rhs.top &&
	lhs.left == rhs.left &&
	lhs.bottom == rhs.bottom &&
	lhs.right == rhs.right
	}
	}

	extension UIOffset : Equatable {
	@_transparent // @fragile
	public static func == (lhs: UIOffset, rhs: UIOffset) -> Bool {
	return lhs.horizontal == rhs.horizontal &&
	lhs.vertical == rhs.vertical
	}
	}

	//===----------------------------------------------------------------------===//
	// Numeric backed types
	//===----------------------------------------------------------------------===//

	@available(swift 4)
	public protocol _UIKitNumericRawRepresentable : RawRepresentable, Comparable where RawValue: Comparable & Numeric {}

	extension _UIKitNumericRawRepresentable {

	public static func <(lhs: Self, rhs: Self) -> Bool {
	return lhs.rawValue < rhs.rawValue
	}

	public static func +(lhs: Self, rhs: RawValue) -> Self {
	return Self(rawValue: lhs.rawValue + rhs)!
	}

	public static func +(lhs: RawValue, rhs: Self) -> Self {
	return Self(rawValue: lhs + rhs.rawValue)!
	}

	public static func -(lhs: Self, rhs: RawValue) -> Self {
	return Self(rawValue: lhs.rawValue - rhs)!
	}

	public static func -(lhs: Self, rhs: Self) -> RawValue {
	return lhs.rawValue - rhs.rawValue
	}

	public static func +=(lhs: inout Self, rhs: RawValue) {
	lhs = Self(rawValue: lhs.rawValue + rhs)!
	}

	public static func -=(lhs: inout Self, rhs: RawValue) {
	lhs = Self(rawValue: lhs.rawValue - rhs)!
	}
	}

	@available(swift 4)
	extension UIFont.Weight : _UIKitNumericRawRepresentable {}

	#if !os(watchOS)
	@available(swift 4)
	extension UILayoutPriority : _UIKitNumericRawRepresentable {}
	#endif

	// These are un-imported macros in UIKit.

	//===----------------------------------------------------------------------===//
	// UIDeviceOrientation
	//===----------------------------------------------------------------------===//

	#if !os(watchOS) && !os(tvOS)
	public extension UIDeviceOrientation {
	var isLandscape: Bool {
	return self == .landscapeLeft \|\| self == .landscapeRight
	}

	var isPortrait: Bool {
	return self == .portrait \|\| self == .portraitUpsideDown
	}

	var isFlat: Bool {
	return self == .faceUp \|\| self == .faceDown
	}

	var isValidInterfaceOrientation: Bool {
	switch self {
	case .portrait, .portraitUpsideDown, .landscapeLeft, .landscapeRight:
	return true
	default:
	return false
	}
	}
	}

	public func UIDeviceOrientationIsLandscape(
	_ orientation: UIDeviceOrientation
	) -> Bool {
	return orientation.isLandscape
	}

	public func UIDeviceOrientationIsPortrait(
	_ orientation: UIDeviceOrientation
	) -> Bool {
	return orientation.isPortrait
	}

	public func UIDeviceOrientationIsValidInterfaceOrientation(
	_ orientation: UIDeviceOrientation) -> Bool
	{
	return orientation.isValidInterfaceOrientation
	}
	#endif

	//===----------------------------------------------------------------------===//
	// UIInterfaceOrientation
	//===----------------------------------------------------------------------===//

	#if !os(watchOS) && !os(tvOS)
	public extension UIInterfaceOrientation {
	var isLandscape: Bool {
	return self == .landscapeLeft \|\| self == .landscapeRight
	}

	var isPortrait: Bool {
	return self == .portrait \|\| self == .portraitUpsideDown
	}
	}

	public func UIInterfaceOrientationIsPortrait(
	_ orientation: UIInterfaceOrientation) -> Bool {
	return orientation.isPortrait
	}

	public func UIInterfaceOrientationIsLandscape(
	_ orientation: UIInterfaceOrientation
	) -> Bool {
	return orientation.isLandscape
	}
	#endif

	// Overlays for variadic initializers.

	#if !os(watchOS) && !os(tvOS)
	public extension UIActionSheet {
	convenience init(title: String?,
	delegate: UIActionSheetDelegate?,
	cancelButtonTitle: String?,
	destructiveButtonTitle: String?,
	// Hack around overload ambiguity with non-variadic constructor.
	// <rdar://problem/16704770>
	otherButtonTitles firstButtonTitle: String,
	_ moreButtonTitles: String...) {
	self.init(title: title,
	delegate: delegate,
	cancelButtonTitle: cancelButtonTitle,
	destructiveButtonTitle: destructiveButtonTitle)
	self.addButton(withTitle: firstButtonTitle)
	for buttonTitle in moreButtonTitles {
	self.addButton(withTitle: buttonTitle)
	}
	}
	}
	#endif

	#if !os(watchOS) && !os(tvOS)
	public extension UIAlertView {
	convenience init(title: String,
	message: String,
	delegate: UIAlertViewDelegate?,
	cancelButtonTitle: String?,
	// Hack around overload ambiguity with non-variadic constructor.
	// <rdar://problem/16704770>
	otherButtonTitles firstButtonTitle: String,
	_ moreButtonTitles: String...) {
	self.init(title: title,
	message: message,
	delegate: delegate,
	cancelButtonTitle: cancelButtonTitle)
	self.addButton(withTitle: firstButtonTitle)
	for buttonTitle in moreButtonTitles {
	self.addButton(withTitle: buttonTitle)
	}
	}
	}
	#endif

	#if !os(watchOS)
	internal struct _UIViewQuickLookState {
	static var views = Set<UIView>()
	}

	extension UIView : _DefaultCustomPlaygroundQuickLookable {
	@available(*, deprecated, message: "UIView._defaultCustomPlaygroundQuickLook will be removed in a future Swift version")
	public var _defaultCustomPlaygroundQuickLook: PlaygroundQuickLook {
	if _UIViewQuickLookState.views.contains(self) {
	return .view(UIImage())
	} else {
	_UIViewQuickLookState.views.insert(self)
	// in case of an empty rectangle abort the logging
	if (bounds.size.width == 0) \|\| (bounds.size.height == 0) {
	return .view(UIImage())
	}

	UIGraphicsBeginImageContextWithOptions(bounds.size, false, 0.0)
	// UIKit is about to update this to be optional, so make it work
	// with both older and newer SDKs. (In this context it should always
	// be present.)
	let ctx: CGContext! = UIGraphicsGetCurrentContext()
	UIColor(white:1.0, alpha:0.0).set()
	ctx.fill(bounds)
	layer.render(in: ctx)

	let image: UIImage! = UIGraphicsGetImageFromCurrentImageContext()

	UIGraphicsEndImageContext()

	_UIViewQuickLookState.views.remove(self)
	return .view(image)
	}
	}
	}
	#endif

	extension UIColor : _ExpressibleByColorLiteral {
	@nonobjc public required convenience init(_colorLiteralRed red: Float,
	green: Float,
	blue: Float, alpha: Float) {
	self.init(red: CGFloat(red), green: CGFloat(green),
	blue: CGFloat(blue), alpha: CGFloat(alpha))
	}
	}

	public typealias _ColorLiteralType = UIColor

	extension UIImage : _ExpressibleByImageLiteral {
	private convenience init!(failableImageLiteral name: String) {
	self.init(named: name)
	}

	public required convenience init(imageLiteralResourceName name: String) {
	self.init(failableImageLiteral: name)
	}
	}

	public typealias _ImageLiteralType = UIImage

	extension UIFontTextStyle {
	@available(iOS 11.0, watchOS 4.0, tvOS 11.0, *)
	public var metrics: UIFontMetrics {
	return UIFontMetrics(forTextStyle: self)
	}
	}

	#if !os(watchOS) // UIContentSizeCategory not available on watchOS
	extension UIContentSizeCategory {

	@available(iOS 11.0, tvOS 11.0, *)
	public var isAccessibilityCategory: Bool {
	return __UIContentSizeCategoryIsAccessibilityCategory(self)
	}

	@available(iOS 11.0, tvOS 11.0, *)
	public static func < (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
	return __UIContentSizeCategoryCompareToCategory(left, right) == .orderedAscending
	}

	@available(iOS 11.0, tvOS 11.0, *)
	public static func <= (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
	return __UIContentSizeCategoryCompareToCategory(left, right) != .orderedDescending
	}

	@available(iOS 11.0, tvOS 11.0, *)
	public static func > (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
	return __UIContentSizeCategoryCompareToCategory(left, right) == .orderedDescending
	}

	@available(iOS 11.0, tvOS 11.0, *)
	public static func >= (left: UIContentSizeCategory, right: UIContentSizeCategory) -> Bool {
	return __UIContentSizeCategoryCompareToCategory(left, right) != .orderedAscending
	}
	}
	#endif

	//===----------------------------------------------------------------------===//
	// Focus
	//===----------------------------------------------------------------------===//

	#if os(iOS) \|\| os(tvOS)
	@available(iOS 11.0, tvOS 11.0, *)
	extension UIFocusEnvironment {
	@available(iOS 11.0, tvOS 11.0, *)
	public func contains(_ environment: UIFocusEnvironment) -> Bool {
	return _swift_UIKit_UIFocusEnvironmentContainsEnvironment(self, environment)
	}
	}

	@available(iOS 11.0, tvOS 11.0, *)
	extension UIFocusItem {
	@available(iOS 11.0, tvOS 11.0, *)
	public var isFocused: Bool {
	return self === UIScreen.main.focusedItem
	}
	}
	#endif

	//===----------------------------------------------------------------------===//
	// NSItemProviderReading/Writing support
	//===----------------------------------------------------------------------===//

	#if os(iOS)

	@available(iOS 11.0, *)
	extension UIDragDropSession {
	@available(iOS 11.0, *)
	public func canLoadObjects<
	T : _ObjectiveCBridgeable
	>(ofClass: T.Type) -> Bool where T._ObjectiveCType : NSItemProviderReading {
	return self.canLoadObjects(ofClass: T._ObjectiveCType.self);
	}
	}

	@available(iOS 11.0, *)
	extension UIDropSession {
	@available(iOS 11.0, *)
	public func loadObjects<
	T : _ObjectiveCBridgeable
	>(
	ofClass: T.Type,
	completion: @escaping ([T]) -> Void
	) -> Progress where T._ObjectiveCType : NSItemProviderReading {
	return self.loadObjects(ofClass: T._ObjectiveCType.self) { nss in
	let natives = nss.map { $0 as! T }
	completion(natives)
	}
	}
	}

	@available(iOS 11.0, *)
	extension UIPasteConfiguration {
	@available(iOS 11.0, *)
	public convenience init<
	T : _ObjectiveCBridgeable
	>(forAccepting _: T.Type) where T._ObjectiveCType : NSItemProviderReading {
	self.init(forAccepting: T._ObjectiveCType.self)
	}

	@available(iOS 11.0, *)
	public func addTypeIdentifiers<
	T : _ObjectiveCBridgeable
	>(forAccepting aClass: T.Type)
	where T._ObjectiveCType : NSItemProviderReading {
	self.addTypeIdentifiers(forAccepting: T._ObjectiveCType.self)
	}
	}


	extension UIPasteboard {
	@available(iOS 11.0, *)
	public func setObjects<
	T : _ObjectiveCBridgeable
	>(_ objects: [T]) where T._ObjectiveCType : NSItemProviderWriting {
	// Using a simpler `$0 as! T._ObjectiveCType` triggers and assertion in
	// the compiler.
	self.setObjects(objects.map { $0._bridgeToObjectiveC() })
	}

	@available(iOS 11.0, *)
	public func setObjects<
	T : _ObjectiveCBridgeable
	>(
	_ objects: [T],
	localOnly: Bool,
	expirationDate: Date?
	) where T._ObjectiveCType : NSItemProviderWriting {
	self.setObjects(
	// Using a simpler `$0 as! T._ObjectiveCType` triggers and assertion in
	// the compiler.
	objects.map { $0._bridgeToObjectiveC() },
	localOnly: localOnly,
	expirationDate: expirationDate)
	}
	}

	#endif