Use enum instead of pair as result type for Template

Stencil/Result.swift

@@ -0,0 +1,33 @@
+//
+//  Result.swift
+//  Stencil
+//
+//  Created by Marius Rackwitz on 26/10/14.
+//  Copyright (c) 2014 Cocode. All rights reserved.
+//
+
+import Foundation
+
+public protocol Error : Printable {
+    
+}
+
+public func ==(lhs:Error, rhs:Error) -> Bool {
+    return lhs.description == rhs.description
+}
+
+public enum Result : Equatable {
+    case Success(string: String)
+    case Error(error: Stencil.Error)
+}
+
+public func ==(lhs:Result, rhs:Result) -> Bool {
+    switch (lhs, rhs) {
+    case (.Success(let lhsValue), .Success(let rhsValue)):
+        return lhsValue == rhsValue
+    case (.Error(let lhsValue), .Error(let rhsValue)):
+        return lhsValue == rhsValue
+    default:
+        return false
+    }
+}