WIP: base::Bind for rvalue references.

base/bind_helpers.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.
 
 // This defines a set of argument wrappers and related factory methods that
 // can be used specify the refcounting and reference semantics of arguments
 // that are bound by the Bind() function in base/bind.h.
 //
 // It also defines a set of simple functions and utilities that people want
 // when using Callback<> and Bind().
@@ skipping 366 matching lines @@
     return scoper_.Pass();
   }
 
  private:
   mutable bool is_valid_;
   mutable T scoper_;
 };
 
 // Unwrap the stored parameters for the wrappers above.
 template <typename T>
-struct UnwrapTraits {
+struct MoveOnlyUnwrapTraits {
+  typedef T&& ForwardType;
+  static ForwardType Unwrap(T& o) { return std::move(o); }
+};
+
+template <typename T>
+struct CopyUnwrapTraits {
   typedef const T& ForwardType;
   static ForwardType Unwrap(const T& o) { return o; }
 };
 
+// BindState<>
+template <typename T, typename U = void>
+struct UnwrapTraits : public std::conditional<base::is_move_only<T>::value,
+                                                 MoveOnlyUnwrapTraits<T>,
+                                                 CopyUnwrapTraits<T>>::type {};
+
+template <typename T>
+struct UnwrapTraits<
+    T,
+    typename std::conditional<false, typename T::value_type, void>::type>
+    : public std::conditional<base::is_move_only<typename T::value_type>::value,
+                              MoveOnlyUnwrapTraits<T>,
+                              CopyUnwrapTraits<T>>::type {};
+
 template <typename T>
 struct UnwrapTraits<UnretainedWrapper<T> > {
   typedef T* ForwardType;
   static ForwardType Unwrap(UnretainedWrapper<T> unretained) {
     return unretained.get();
   }
 };
 
 template <typename T>
 struct UnwrapTraits<ConstRefWrapper<T> > {
@@ skipping 191 matching lines @@
 BASE_EXPORT void DoNothing();
 
 template<typename T>
 void DeletePointer(T* obj) {
   delete obj;
 }
 
 }  // namespace base
 
 #endif  // BASE_BIND_HELPERS_H_