Initial draft of DataProtocol ContiguousCollection and new inline Data

stdlib/public/Darwin/Foundation/NSData+DataProtocol.swift

@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2018 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
+//
+//===----------------------------------------------------------------------===//
+
+
+extension NSData : DataProtocol {
+
+    @nonobjc
+    public var startIndex: Int { return 0 }
+
+    @nonobjc
+    public var endIndex: Int { return length }
+
+    @nonobjc
+    public func lastRange<D, R>(of data: D, in r: R) -> Range<Int>? where D : DataProtocol, R : RangeExpression, NSData.Index == R.Bound {
+        return Range<Int>(range(of: Data(data), options: .backwards, in: NSRange(r)))
+    }
+
+    @nonobjc
+    public func firstRange<D, R>(of data: D, in r: R) -> Range<Int>? where D : DataProtocol, R : RangeExpression, NSData.Index == R.Bound {
+        return Range<Int>(range(of: Data(data), in: NSRange(r)))
+    }
+
+    @nonobjc
+    public var regions: [Data] {
+        var datas = [Data]()
+        enumerateBytes { (ptr, range, stop) in
+            datas.append(Data(bytesNoCopy: UnsafeMutableRawPointer(mutating: ptr), count: range.length, deallocator: .custom({ (ptr: UnsafeMutableRawPointer, count: Int) -> Void in
+                withExtendedLifetime(self) { }
+            })))
+        }
+        return datas
+    }
+
+    @nonobjc
+    public subscript(position: Int) -> UInt8 {
+        var byte = UInt8(0)
+        enumerateBytes { (ptr, range, stop) in
+            if range.location <= position && position < range.upperBound {
+                byte = ptr.load(fromByteOffset: range.location - position, as: UInt8.self)
+                stop.pointee = true
+            }
+        }
+        return byte
+    }
+}