1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/sandbox/chromium/base/template_util.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,108 @@
1.4 +// Copyright (c) 2011 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#ifndef BASE_TEMPLATE_UTIL_H_
1.9 +#define BASE_TEMPLATE_UTIL_H_
1.10 +
1.11 +#include <cstddef> // For size_t.
1.12 +
1.13 +#include "build/build_config.h"
1.14 +
1.15 +namespace base {
1.16 +
1.17 +// template definitions from tr1
1.18 +
1.19 +template<class T, T v>
1.20 +struct integral_constant {
1.21 + static const T value = v;
1.22 + typedef T value_type;
1.23 + typedef integral_constant<T, v> type;
1.24 +};
1.25 +
1.26 +template <class T, T v> const T integral_constant<T, v>::value;
1.27 +
1.28 +typedef integral_constant<bool, true> true_type;
1.29 +typedef integral_constant<bool, false> false_type;
1.30 +
1.31 +template <class T> struct is_pointer : false_type {};
1.32 +template <class T> struct is_pointer<T*> : true_type {};
1.33 +
1.34 +template <class T, class U> struct is_same : public false_type {};
1.35 +template <class T> struct is_same<T,T> : true_type {};
1.36 +
1.37 +template<class> struct is_array : public false_type {};
1.38 +template<class T, size_t n> struct is_array<T[n]> : public true_type {};
1.39 +template<class T> struct is_array<T[]> : public true_type {};
1.40 +
1.41 +template <class T> struct is_non_const_reference : false_type {};
1.42 +template <class T> struct is_non_const_reference<T&> : true_type {};
1.43 +template <class T> struct is_non_const_reference<const T&> : false_type {};
1.44 +
1.45 +template <class T> struct is_void : false_type {};
1.46 +template <> struct is_void<void> : true_type {};
1.47 +
1.48 +namespace internal {
1.49 +
1.50 +// Types YesType and NoType are guaranteed such that sizeof(YesType) <
1.51 +// sizeof(NoType).
1.52 +typedef char YesType;
1.53 +
1.54 +struct NoType {
1.55 + YesType dummy[2];
1.56 +};
1.57 +
1.58 +// This class is an implementation detail for is_convertible, and you
1.59 +// don't need to know how it works to use is_convertible. For those
1.60 +// who care: we declare two different functions, one whose argument is
1.61 +// of type To and one with a variadic argument list. We give them
1.62 +// return types of different size, so we can use sizeof to trick the
1.63 +// compiler into telling us which function it would have chosen if we
1.64 +// had called it with an argument of type From. See Alexandrescu's
1.65 +// _Modern C++ Design_ for more details on this sort of trick.
1.66 +
1.67 +struct ConvertHelper {
1.68 + template <typename To>
1.69 + static YesType Test(To);
1.70 +
1.71 + template <typename To>
1.72 + static NoType Test(...);
1.73 +
1.74 + template <typename From>
1.75 + static From& Create();
1.76 +};
1.77 +
1.78 +// Used to determine if a type is a struct/union/class. Inspired by Boost's
1.79 +// is_class type_trait implementation.
1.80 +struct IsClassHelper {
1.81 + template <typename C>
1.82 + static YesType Test(void(C::*)(void));
1.83 +
1.84 + template <typename C>
1.85 + static NoType Test(...);
1.86 +};
1.87 +
1.88 +} // namespace internal
1.89 +
1.90 +// Inherits from true_type if From is convertible to To, false_type otherwise.
1.91 +//
1.92 +// Note that if the type is convertible, this will be a true_type REGARDLESS
1.93 +// of whether or not the conversion would emit a warning.
1.94 +template <typename From, typename To>
1.95 +struct is_convertible
1.96 + : integral_constant<bool,
1.97 + sizeof(internal::ConvertHelper::Test<To>(
1.98 + internal::ConvertHelper::Create<From>())) ==
1.99 + sizeof(internal::YesType)> {
1.100 +};
1.101 +
1.102 +template <typename T>
1.103 +struct is_class
1.104 + : integral_constant<bool,
1.105 + sizeof(internal::IsClassHelper::Test<T>(0)) ==
1.106 + sizeof(internal::YesType)> {
1.107 +};
1.108 +
1.109 +} // namespace base
1.110 +
1.111 +#endif // BASE_TEMPLATE_UTIL_H_
