Updates for review comments.

Author: jshier

stdlib/public/core/Result.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// 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
@@ -128,15 +128,4 @@ extension Result where Error == Swift.Error {
 
 extension Result : Equatable where Value : Equatable, Error : Equatable { }
 
-extension Result : Hashable where Value : Hashable, Error : Hashable {
-  public func hash(into hasher: inout Hasher) {
-    switch self {
-    case let .value(value):
-      hasher.combine(value)
-      hasher.combine(Optional<Error>.none)
-    case let .error(error):
-      hasher.combine(Optional<Value>.none)
-      hasher.combine(error)
-    }
-  }
-}
+extension Result : Hashable where Value : Hashable, Error : Hashable { }

test/stdlib/Result.swift

@@ -21,14 +21,14 @@ fileprivate extension Result {
     case .error:
       return nil
     }
-    
-    var error: Error? {
-      switch self {
-      case .value:
-        return nil
-      case let .error(error):
-        return error
-      }
+  }
+  
+  var error: Error? {
+    switch self {
+    case .value:
+      return nil
+    case let .error(error):
+      return error
     }
   }
 }
@@ -71,14 +71,7 @@ ResultTests.test("Throwing Initialization and Unwrapping") {
   let result1 = Result { try throwing() }
   let result2 = Result { try notThrowing() }
 
-  // Kept getting enum case 'error' cannot be used as an instance member, so get value manually.
-  switch result1 {
-  case let .error(error):
-    expectEqual(error as? Err, Err.err)
-  case .value:
-    expectUnreachable() 
-  }
-  
+  expectEqual(result1.error as? Err, Err.err)
   expectEqual(result2.value, string)
 
   do {