Index: third_party/cld/base/type_traits.h |
=================================================================== |
--- third_party/cld/base/type_traits.h (revision 0) |
+++ third_party/cld/base/type_traits.h (revision 0) |
@@ -0,0 +1,198 @@ |
+// Copyright (c) 2006-2009 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 code is compiled directly on many platforms, including client |
+// platforms like Windows, Mac, and embedded systems. Before making |
+// any changes here, make sure that you're not breaking any platforms. |
+// |
+// |
+// Define a small subset of tr1 type traits. The traits we define are: |
+// is_integral |
+// is_floating_point |
+// is_pointer |
+// is_reference |
+// is_pod |
+// has_trivial_constructor |
+// has_trivial_copy |
+// has_trivial_assign |
+// has_trivial_destructor |
+// remove_const |
+// remove_volatile |
+// remove_cv |
+// remove_reference |
+// remove_pointer |
+// is_convertible |
+// We can add more type traits as required. |
+ |
+#ifndef BASE_TYPE_TRAITS_H_ |
+#define BASE_TYPE_TRAITS_H_ |
+ |
+#include "third_party/cld/base/template_util.h" // For true_type and false_type |
+#include <utility> // For pair |
+ |
+namespace base { |
+ |
+// is_integral is false except for the built-in integer types. |
+template <class T> struct is_integral : false_type { }; |
+template<> struct is_integral<bool> : true_type { }; |
+template<> struct is_integral<char> : true_type { }; |
+template<> struct is_integral<unsigned char> : true_type { }; |
+template<> struct is_integral<signed char> : true_type { }; |
+#if defined(_MSC_VER) |
+// wchar_t is not by default a distinct type from unsigned short in |
+// Microsoft C. |
+// See http://msdn2.microsoft.com/en-us/library/dh8che7s(VS.80).aspx |
+template<> struct is_integral<__wchar_t> : true_type { }; |
+#else |
+template<> struct is_integral<wchar_t> : true_type { }; |
+#endif |
+template<> struct is_integral<short> : true_type { }; |
+template<> struct is_integral<unsigned short> : true_type { }; |
+template<> struct is_integral<int> : true_type { }; |
+template<> struct is_integral<unsigned int> : true_type { }; |
+template<> struct is_integral<long> : true_type { }; |
+template<> struct is_integral<unsigned long> : true_type { }; |
+template<> struct is_integral<long long> : true_type { }; |
+template<> struct is_integral<unsigned long long> : true_type { }; |
+ |
+ |
+// is_floating_point is false except for the built-in floating-point types. |
+template <class T> struct is_floating_point : false_type { }; |
+template<> struct is_floating_point<float> : true_type { }; |
+template<> struct is_floating_point<double> : true_type { }; |
+template<> struct is_floating_point<long double> : true_type { }; |
+ |
+ |
+// is_pointer is false except for pointer types. |
+template <class T> struct is_pointer : false_type { }; |
+template <class T> struct is_pointer<T*> : true_type { }; |
+ |
+ |
+// is_reference is false except for reference types. |
+template<typename T> struct is_reference : false_type {}; |
+template<typename T> struct is_reference<T&> : true_type {}; |
+ |
+ |
+// We can't get is_pod right without compiler help, so fail conservatively. |
+// We will assume it's false except for arithmetic types and pointers, |
+// and const versions thereof. Note that std::pair is not a POD. |
+template <class T> struct is_pod |
+ : integral_constant<bool, (is_integral<T>::value || |
+ is_floating_point<T>::value || |
+ is_pointer<T>::value)> { }; |
+template <class T> struct is_pod<const T> : is_pod<T> { }; |
+ |
+ |
+// We can't get has_trivial_constructor right without compiler help, so |
+// fail conservatively. We will assume it's false except for: (1) types |
+// for which is_pod is true. (2) std::pair of types with trivial |
+// constructors. (3) array of a type with a trivial constructor. |
+// (4) const versions thereof. |
+template <class T> struct has_trivial_constructor : is_pod<T> { }; |
+template <class T, class U> struct has_trivial_constructor<std::pair<T, U> > |
+ : integral_constant<bool, |
+ (has_trivial_constructor<T>::value && |
+ has_trivial_constructor<U>::value)> { }; |
+template <class A, int N> struct has_trivial_constructor<A[N]> |
+ : has_trivial_constructor<A> { }; |
+template <class T> struct has_trivial_constructor<const T> |
+ : has_trivial_constructor<T> { }; |
+ |
+// We can't get has_trivial_copy right without compiler help, so fail |
+// conservatively. We will assume it's false except for: (1) types |
+// for which is_pod is true. (2) std::pair of types with trivial copy |
+// constructors. (3) array of a type with a trivial copy constructor. |
+// (4) const versions thereof. |
+template <class T> struct has_trivial_copy : is_pod<T> { }; |
+template <class T, class U> struct has_trivial_copy<std::pair<T, U> > |
+ : integral_constant<bool, |
+ (has_trivial_copy<T>::value && |
+ has_trivial_copy<U>::value)> { }; |
+template <class A, int N> struct has_trivial_copy<A[N]> |
+ : has_trivial_copy<A> { }; |
+template <class T> struct has_trivial_copy<const T> : has_trivial_copy<T> { }; |
+ |
+// We can't get has_trivial_assign right without compiler help, so fail |
+// conservatively. We will assume it's false except for: (1) types |
+// for which is_pod is true. (2) std::pair of types with trivial copy |
+// constructors. (3) array of a type with a trivial assign constructor. |
+template <class T> struct has_trivial_assign : is_pod<T> { }; |
+template <class T, class U> struct has_trivial_assign<std::pair<T, U> > |
+ : integral_constant<bool, |
+ (has_trivial_assign<T>::value && |
+ has_trivial_assign<U>::value)> { }; |
+template <class A, int N> struct has_trivial_assign<A[N]> |
+ : has_trivial_assign<A> { }; |
+ |
+// We can't get has_trivial_destructor right without compiler help, so |
+// fail conservatively. We will assume it's false except for: (1) types |
+// for which is_pod is true. (2) std::pair of types with trivial |
+// destructors. (3) array of a type with a trivial destructor. |
+// (4) const versions thereof. |
+template <class T> struct has_trivial_destructor : is_pod<T> { }; |
+template <class T, class U> struct has_trivial_destructor<std::pair<T, U> > |
+ : integral_constant<bool, |
+ (has_trivial_destructor<T>::value && |
+ has_trivial_destructor<U>::value)> { }; |
+template <class A, int N> struct has_trivial_destructor<A[N]> |
+ : has_trivial_destructor<A> { }; |
+template <class T> struct has_trivial_destructor<const T> |
+ : has_trivial_destructor<T> { }; |
+ |
+// Specified by TR1 [4.7.1] |
+template<typename T> struct remove_const { typedef T type; }; |
+template<typename T> struct remove_const<T const> { typedef T type; }; |
+template<typename T> struct remove_volatile { typedef T type; }; |
+template<typename T> struct remove_volatile<T volatile> { typedef T type; }; |
+template<typename T> struct remove_cv { |
+ typedef typename remove_const<typename remove_volatile<T>::type>::type type; |
+}; |
+ |
+ |
+// Specified by TR1 [4.7.2] |
+template<typename T> struct remove_reference { typedef T type; }; |
+template<typename T> struct remove_reference<T&> { typedef T type; }; |
+ |
+// Specified by TR1 [4.7.4] Pointer modifications. |
+template<typename T> struct remove_pointer { typedef T type; }; |
+template<typename T> struct remove_pointer<T*> { typedef T type; }; |
+template<typename T> struct remove_pointer<T* const> { typedef T type; }; |
+template<typename T> struct remove_pointer<T* volatile> { typedef T type; }; |
+template<typename T> struct remove_pointer<T* const volatile> { |
+ typedef T type; }; |
+ |
+// Specified by TR1 [4.6] Relationships between types |
+#ifndef _MSC_VER |
+namespace internal { |
+ |
+// This class is an implementation detail for is_convertible, and you |
+// don't need to know how it works to use is_convertible. For those |
+// who care: we declare two different functions, one whose argument is |
+// of type To and one with a variadic argument list. We give them |
+// return types of different size, so we can use sizeof to trick the |
+// compiler into telling us which function it would have chosen if we |
+// had called it with an argument of type From. See Alexandrescu's |
+// _Modern C++ Design_ for more details on this sort of trick. |
+ |
+template <typename From, typename To> |
+struct ConvertHelper { |
+ static small_ Test(To); |
+ static big_ Test(...); |
+ static From Create(); |
+}; |
+} // namespace internal |
+ |
+// Inherits from true_type if From is convertible to To, false_type otherwise. |
+template <typename From, typename To> |
+struct is_convertible |
+ : integral_constant<bool, |
+ sizeof(internal::ConvertHelper<From, To>::Test( |
+ internal::ConvertHelper<From, To>::Create())) |
+ == sizeof(small_)> { |
+}; |
+#endif |
+ |
+} // Close namespace base |
+ |
+#endif // BASE_TYPE_TRAITS_H_ |
Property changes on: third_party\cld\base\type_traits.h |
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Added: svn:eol-style |
+ LF |