WIP: base::Bind for rvalue references.

base/callback_internal.h

Index: base/callback_internal.h
diff --git a/base/callback_internal.h b/base/callback_internal.h
index 4b47bc7978db33f0946a9c30645d4b35f241751e..a36aa1fa6f71c58ff9f837fae3c45079bb996bbe 100644
--- a/base/callback_internal.h
+++ b/base/callback_internal.h
@@ -127,11 +127,25 @@ struct CallbackParamTraitsForNonMoveOnlyType;
 // parameters by const reference. In this case, we end up passing an actual
 // array type in the initializer list which C++ does not allow.  This will
 // break passing of C-string literals.
-template <typename T>
+template <typename T, typename = void>
 struct CallbackParamTraits
-    : std::conditional<IsMoveOnlyType<T>::value,
-         CallbackParamTraitsForMoveOnlyType<T>,
-         CallbackParamTraitsForNonMoveOnlyType<T>>::type {
+    : std::conditional<is_move_only<typename std::decay<T>::type>::value,
+                       CallbackParamTraitsForMoveOnlyType<T>,
+                       CallbackParamTraitsForNonMoveOnlyType<T>>::type {
+};
+
+template <typename T>
+struct CallbackParamTraits<
+    T,
+    typename std::conditional<false,
+                              typename std::decay<T>::type::value_type,
+                              void>::type>
+    : public std::conditional<
+          base::is_move_only<typename std::decay<T>::type>::value ||
+              base::is_move_only<
+                  typename std::decay<T>::type::value_type>::value,
+          CallbackParamTraitsForMoveOnlyType<T>,
+          CallbackParamTraitsForNonMoveOnlyType<T>>::type {
 };
 
 template <typename T>
@@ -145,11 +159,11 @@ struct CallbackParamTraitsForNonMoveOnlyType {
 // this will guard against us accidentally storing a reference parameter.
 //
 // The ForwardType should only be used for unbound arguments.
-template <typename T>
-struct CallbackParamTraitsForNonMoveOnlyType<T&> {
-  typedef T& ForwardType;
-  typedef T StorageType;
-};
+// template <typename T>
+// struct CallbackParamTraits<T&> {
+  // typedef T& ForwardType;
+  // typedef T StorageType;
+// };
 
 // Note that for array types, we implicitly add a const in the conversion. This
 // means that it is not possible to bind array arguments to functions that take
@@ -184,7 +198,7 @@ struct CallbackParamTraitsForNonMoveOnlyType<T[]> {
 // function or a cast would not be usable with Callback<> or Bind().
 template <typename T>
 struct CallbackParamTraitsForMoveOnlyType {
-  typedef T ForwardType;
+  typedef typename std::remove_reference<T>::type&& ForwardType;
   typedef T StorageType;
 };
 
@@ -214,6 +228,12 @@ typename enable_if<IsMoveOnlyType<T>::value, T>::type CallbackForward(T& t) {
   return t.Pass();
 }
 
+template <typename T>
+auto CallbackForward2(T&& t) ->
+    typename CallbackParamTraits<T>::ForwardType {
+  return static_cast<typename CallbackParamTraits<T>::ForwardType>(t);
+}
+
 }  // namespace internal
 }  // namespace base