stdlib/public/SDK/Foundation/Foundation.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

@_exported import Foundation // Clang module
import CoreFoundation
import CoreGraphics

//===----------------------------------------------------------------------===//
// NSObject
//===----------------------------------------------------------------------===//

// These conformances should be located in the `ObjectiveC` module, but they can't
// be placed there because string bridging is not available there.
extension NSObject : CustomStringConvertible {}
extension NSObject : CustomDebugStringConvertible {}

public let NSNotFound: Int = .max

//===----------------------------------------------------------------------===//
// NSLocalizedString
//===----------------------------------------------------------------------===//

/// Returns a localized string, using the main bundle if one is not specified.
public
func NSLocalizedString(_ key: String,
                       tableName: String? = nil,
                       bundle: Bundle = Bundle.main,
                       value: String = "",
                       comment: String) -> String {
  return bundle.localizedString(forKey: key, value:value, table:tableName)
}

//===----------------------------------------------------------------------===//
// NSLog
//===----------------------------------------------------------------------===//

public func NSLog(_ format: String, _ args: CVarArg...) {
  withVaList(args) { NSLogv(format, $0) }
}

//===----------------------------------------------------------------------===//
// AnyHashable
//===----------------------------------------------------------------------===//

extension AnyHashable : _ObjectiveCBridgeable {
  public func _bridgeToObjectiveC() -> NSObject {
    // This is unprincipled, but pretty much any object we'll encounter in
    // Swift is NSObject-conforming enough to have -hash and -isEqual:.
    return unsafeBitCast(base as AnyObject, to: NSObject.self)
  }

  public static func _forceBridgeFromObjectiveC(
    _ x: NSObject,
    result: inout AnyHashable?
  ) {
    result = AnyHashable(x)
  }

  public static func _conditionallyBridgeFromObjectiveC(
    _ x: NSObject,
    result: inout AnyHashable?
  ) -> Bool {
    self._forceBridgeFromObjectiveC(x, result: &result)
    return result != nil
  }

  public static func _unconditionallyBridgeFromObjectiveC(
    _ source: NSObject?
  ) -> AnyHashable {
    // `nil` has historically been used as a stand-in for an empty
    // string; map it to an empty string.
    if _slowPath(source == nil) { return AnyHashable(String()) }
    return AnyHashable(source!)
  }
}

//===----------------------------------------------------------------------===//
// CVarArg for bridged types
//===----------------------------------------------------------------------===//

extension CVarArg where Self: _ObjectiveCBridgeable {
  /// Default implementation for bridgeable types.
  public var _cVarArgEncoding: [Int] {
    let object = self._bridgeToObjectiveC()
    _autorelease(object)
    return _encodeBitsAsWords(object)
  }
}

//===----------------------------------------------------------------------===//
// Runtime support for NSKeyedArchives
//===----------------------------------------------------------------------===//

@_silgen_name("swift_registerClassNameForArchiving")
public func _registerClassNameForArchiving(_ nameForClass: UnsafePointer<CChar>,
                                           _ classType: AnyClass) {
  // If it's not possible to create a String from the name, it should abort
  // and not fail silently.
  let nameStr = String(utf8String: nameForClass)!

  // Register the class name mapping for archiving and unarchiving.
  NSKeyedArchiver.setClassName(nameStr, for: classType)
  NSKeyedUnarchiver.setClass(classType, forClassName: nameStr)
}