Unified callback system.

base/template_util.h

 // Copyright (c) 2010 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_TEMPLATE_UTIL_H_
 #define BASE_TEMPLATE_UTIL_H_
 #pragma once
 
 #include "build/build_config.h"
 
 namespace base {
 
 // template definitions from tr1
 
 template<class T, T v>
 struct integral_constant {
   static const T value = v;
   typedef T value_type;
   typedef integral_constant<T, v> type;
 };
 
 template <class T, T v> const T integral_constant<T, v>::value;
 
 typedef integral_constant<bool, true> true_type;
 typedef integral_constant<bool, false> false_type;
 
 template <class T> struct is_pointer : false_type {};
 template <class T> struct is_pointer<T*> : true_type {};
 
+template<class> struct is_array : public false_type {};
+template<class T, size_t n> struct is_array<T[n]> : public true_type {};
+template<class T> struct is_array<T[]> : public true_type {};
+
+template <class T> struct is_non_const_reference : false_type {};
+template <class T> struct is_non_const_reference<T&> : true_type {};
+template <class T> struct is_non_const_reference<const T&> : false_type {};
+
 namespace internal {
 
 // Types small_ and big_ are guaranteed such that sizeof(small_) <
 // sizeof(big_)
 typedef char small_;
 
 struct big_ {
   small_ dummy[2];
 };
 
@@ skipping 28 matching lines @@
                         sizeof(internal::ConvertHelper<From, To>::Test(
                                   internal::ConvertHelper<From, To>::Create()))
                         == sizeof(internal::small_)> {
 };
 
 #endif  // !defined(OS_WIN)
 
 }  // namespace base
 
 #endif  // BASE_TEMPLATE_UTIL_H_