Mojo: request/response bindings

mojo/public/bindings/lib/callback_internal.h

Index: mojo/public/bindings/lib/callback_internal.h
diff --git a/mojo/public/bindings/lib/callback_internal.h b/mojo/public/bindings/lib/callback_internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..4e7e9967886f88fa7ea46aa55188fd9aca384301
--- /dev/null
+++ b/mojo/public/bindings/lib/callback_internal.h
@@ -0,0 +1,55 @@
+// Copyright 2014 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 MOJO_PUBLIC_BINDINGS_LIB_CALLBACK_INTERNAL_H_
+#define MOJO_PUBLIC_BINDINGS_LIB_CALLBACK_INTERNAL_H_
+
+#include "mojo/public/bindings/lib/bindings_internal.h"
+
+namespace mojo {
+namespace internal {
+
+template <typename T, bool is_object_type = TypeTraits<T>::kIsObject>
+struct Callback_ParamTraits {};
+
+template <typename T>
+struct Callback_ParamTraits<T, true> {
+  typedef const T& ForwardType;
+  static const bool kIsScopedHandle = false;
+};
+
+template <typename T>
+struct Callback_ParamTraits<T, false> {
+  typedef T ForwardType;
+  static const bool kIsScopedHandle = false;
+};
+
+template <typename H>
+struct Callback_ParamTraits<ScopedHandleBase<H>, true> {
+  typedef ScopedHandleBase<H> ForwardType;
+  static const bool kIsScopedHandle = true;
+};
+
+template<bool B, typename T = void>
+struct EnableIf {};
+
+template<typename T>
+struct EnableIf<true, T> { typedef T type; };
+
+template <typename T>
+typename EnableIf<!Callback_ParamTraits<T>::kIsScopedHandle, T>::type&
+    Callback_Forward(T& t) {
+  return t;
+}
+
+template <typename T>
+typename EnableIf<Callback_ParamTraits<T>::kIsScopedHandle, T>::type
+    Callback_Forward(T& t) {
+  return t.Pass();
+}
+
+}  // namespace internal
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_BINDINGS_LIB_CALLBACK_INTERNAL_H_