Do Perfect Forwarding from base::Bind to BindState storage

base/bind_internal.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_INTERNAL_H_
 #define BASE_BIND_INTERNAL_H_
 
 #include <stddef.h>
 
 #include <type_traits>
@@ skipping 86 matching lines @@
 
 // BindsArrayToFirstArg selects true_type when |is_method| is true and the first
 // item of |Args| is an array type.
 // Implementation note: This non-specialized case handles !is_method case and
 // zero-arity case only.  Other cases should be handled by the specialization
 // below.
 template <bool is_method, typename... Args>
 struct BindsArrayToFirstArg : false_type {};
 
 template <typename T, typename... Args>
-struct BindsArrayToFirstArg<true, T, Args...> : is_array<T> {};
+struct BindsArrayToFirstArg<true, T, Args...>
+    : is_array<typename std::remove_reference<T>::type> {};
 
 // HasRefCountedParamAsRawPtr is the same to HasRefCountedTypeAsRawPtr except
 // when |is_method| is true HasRefCountedParamAsRawPtr skips the first argument.
 // Implementation note: This non-specialized case handles !is_method case and
 // zero-arity case only.  Other cases should be handled by the specialization
 // below.
 template <bool is_method, typename... Args>
 struct HasRefCountedParamAsRawPtr : HasRefCountedTypeAsRawPtr<Args...> {};
 
 template <typename T, typename... Args>
@@ skipping 276 matching lines @@
   using InvokeHelperType =
       InvokeHelper<IsWeakCall::value, R, Runnable, InvokeHelperArgs>;
 
   using UnboundArgs = DropTypeListItem<sizeof...(BoundArgs), TypeList<Args...>>;
 
  public:
   using InvokerType = Invoker<BoundIndices, StorageType, Unwrappers,
                               InvokeHelperType, UnboundForwardRunType>;
   using UnboundRunType = MakeFunctionType<R, UnboundArgs>;
 
-  BindState(const Runnable& runnable, const BoundArgs&... bound_args)
+  template <typename... ForwardArgs>
+  BindState(const Runnable& runnable, ForwardArgs&&... bound_args)
       : BindStateBase(&Destroy),
         runnable_(runnable),
         ref_(bound_args...),
-        bound_args_(bound_args...) {}
+        bound_args_(std::forward<ForwardArgs>(bound_args)...) {}
 
   RunnableType runnable_;
   MaybeScopedRefPtr<HasIsMethodTag<Runnable>::value, BoundArgs...> ref_;
   Tuple<BoundArgs...> bound_args_;
 
  private:
   ~BindState() {}
 
   static void Destroy(BindStateBase* self) {
     delete static_cast<BindState*>(self);
   }
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_BIND_INTERNAL_H_