Refactor gmock_mutant.h

base/bind.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_BIND_H_
 #define BASE_BIND_H_
 
 #include "base/bind_internal.h"
 
 // -----------------------------------------------------------------------------
@@ skipping 28 matching lines @@
 // via an indirection like we do below.
 //
 // TODO(ajwong): We might be able to avoid this now, but need to test.
 //
 // It is possible to move most of the static_assert into BindState<>, but it
 // feels a little nicer to have the asserts here so people do not need to crack
 // open bind_internal.h.  On the other hand, it makes Bind() harder to read.
 
 namespace base {
 
+namespace internal {
+
+// Don't use Alias Template directly here to avoid a compile error on MSVC2013.
 template <typename Functor, typename... Args>
-base::Callback<
-    typename internal::BindState<
-        typename internal::FunctorTraits<Functor>::RunnableType,
-        typename internal::FunctorTraits<Functor>::RunType,
-        typename std::decay<Args>::type...>::UnboundRunType>
+struct MakeUnboundRunTypeImpl {
+  using Type =
+      typename BindState<
+          typename FunctorTraits<Functor>::RunnableType,
+          typename FunctorTraits<Functor>::RunType,
+          typename std::decay<Args>::type...>::UnboundRunType;
+};
+
+}  // namespace internal
+
+template <typename Functor, typename... Args>
+using MakeUnboundRunType =
+    typename internal::MakeUnboundRunTypeImpl<Functor, Args...>::Type;
+
+template <typename Functor, typename... Args>
+base::Callback<MakeUnboundRunType<Functor, Args...>>
 Bind(Functor functor, Args&&... args) {
   // Type aliases for how to store and run the functor.
   using RunnableType = typename internal::FunctorTraits<Functor>::RunnableType;
   using RunType = typename internal::FunctorTraits<Functor>::RunType;
 
   // Use RunnableType::RunType instead of RunType above because our
   // checks below for bound references need to know what the actual
   // functor is going to interpret the argument as.
   using BoundRunType = typename RunnableType::RunType;
 
@@ skipping 25 matching lines @@
       RunnableType, RunType, typename std::decay<Args>::type...>;
 
   return Callback<typename BindState::UnboundRunType>(
       new BindState(internal::MakeRunnable(functor),
                     std::forward<Args>(args)...));
 }
 
 }  // namespace base
 
 #endif  // BASE_BIND_H_