1
2// (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard
3// Hinnant & John Maddock 2000.
4// Use, modification and distribution are subject to the Boost Software License,
5// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt).
7//
8// See http://www.boost.org/libs/type_traits for most recent version including documentation.
9
10
11#ifndef BOOST_TT_IS_ENUM_HPP_INCLUDED
12#define BOOST_TT_IS_ENUM_HPP_INCLUDED
13
14#include <boost/type_traits/intrinsics.hpp>
15#ifndef BOOST_IS_ENUM
16#include <boost/type_traits/add_reference.hpp>
17#include <boost/type_traits/is_arithmetic.hpp>
18#include <boost/type_traits/is_reference.hpp>
19#include <boost/type_traits/is_convertible.hpp>
20#include <boost/type_traits/is_array.hpp>
21#ifdef __GNUC__
22#include <boost/type_traits/is_function.hpp>
23#endif
24#include <boost/type_traits/config.hpp>
25#if defined(BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION)
26# include <boost/type_traits/is_class.hpp>
27# include <boost/type_traits/is_union.hpp>
28#endif
29#endif
30
31// should be the last #include
32#include <boost/type_traits/detail/bool_trait_def.hpp>
33
34namespace boost {
35
36#ifndef BOOST_IS_ENUM
37#if !(defined(__BORLANDC__) && (__BORLANDC__ <= 0x551))
38
39namespace detail {
40
41#if defined(BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION)
42
43template <typename T>
44struct is_class_or_union
45{
46 BOOST_STATIC_CONSTANT(bool, value =
47 (::boost::type_traits::ice_or<
48 ::boost::is_class<T>::value
49 , ::boost::is_union<T>::value
50 >::value));
51};
52
53#else
54
55template <typename T>
56struct is_class_or_union
57{
58# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581))// we simply can't detect it this way.
59 BOOST_STATIC_CONSTANT(bool, value = false);
60# else
61 template <class U> static ::boost::type_traits::yes_type is_class_or_union_tester(void(U::*)(void));
62
63# if BOOST_WORKAROUND(__MWERKS__, <= 0x3000) // no SFINAE
64 static ::boost::type_traits::no_type is_class_or_union_tester(...);
65 BOOST_STATIC_CONSTANT(
66 bool, value = sizeof(is_class_or_union_tester(0)) == sizeof(::boost::type_traits::yes_type));
67# else
68 template <class U>
69 static ::boost::type_traits::no_type is_class_or_union_tester(...);
70 BOOST_STATIC_CONSTANT(
71 bool, value = sizeof(is_class_or_union_tester<T>(0)) == sizeof(::boost::type_traits::yes_type));
72# endif
73# endif
74};
75#endif
76
77struct int_convertible
78{
79 int_convertible(int);
80};
81
82// Don't evaluate convertibility to int_convertible unless the type
83// is non-arithmetic. This suppresses warnings with GCC.
84template <bool is_typename_arithmetic_or_reference = true>
85struct is_enum_helper
86{
87 template <typename T> struct type
88 {
89 BOOST_STATIC_CONSTANT(bool, value = false);
90 };
91};
92
93template <>
94struct is_enum_helper<false>
95{
96 template <typename T> struct type
97 : public ::boost::is_convertible<typename boost::add_reference<T>::type,::boost::detail::int_convertible>
98 {
99 };
100};
101
102template <typename T> struct is_enum_impl
103{
104 //typedef ::boost::add_reference<T> ar_t;
105 //typedef typename ar_t::type r_type;
106
107#if defined(__GNUC__)
108
109#ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
110
111 // We MUST check for is_class_or_union on conforming compilers in
112 // order to correctly deduce that noncopyable types are not enums
113 // (dwa 2002/04/15)...
114 BOOST_STATIC_CONSTANT(bool, selector =
115 (::boost::type_traits::ice_or<
116 ::boost::is_arithmetic<T>::value
117 , ::boost::is_reference<T>::value
118 , ::boost::is_function<T>::value
119 , is_class_or_union<T>::value
120 , is_array<T>::value
121 >::value));
122#else
123 // ...however, not checking is_class_or_union on non-conforming
124 // compilers prevents a dependency recursion.
125 BOOST_STATIC_CONSTANT(bool, selector =
126 (::boost::type_traits::ice_or<
127 ::boost::is_arithmetic<T>::value
128 , ::boost::is_reference<T>::value
129 , ::boost::is_function<T>::value
130 , is_array<T>::value
131 >::value));
132#endif // BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
133
134#else // !defined(__GNUC__):
135
136 BOOST_STATIC_CONSTANT(bool, selector =
137 (::boost::type_traits::ice_or<
138 ::boost::is_arithmetic<T>::value
139 , ::boost::is_reference<T>::value
140 , is_class_or_union<T>::value
141 , is_array<T>::value
142 >::value));
143
144#endif
145
146#if BOOST_WORKAROUND(__BORLANDC__, < 0x600)
147 typedef ::boost::detail::is_enum_helper<
148 ::boost::detail::is_enum_impl<T>::selector
149 > se_t;
150#else
151 typedef ::boost::detail::is_enum_helper<selector> se_t;
152#endif
153
154 typedef typename se_t::template type<T> helper;
155 BOOST_STATIC_CONSTANT(bool, value = helper::value);
156};
157
158// these help on compilers with no partial specialization support:
159BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_enum,void,false)
160#ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
161BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_enum,void const,false)
162BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_enum,void volatile,false)
163BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_enum,void const volatile,false)
164#endif
165
166} // namespace detail
167
168BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_enum,T,::boost::detail::is_enum_impl<T>::value)
169
170#else // __BORLANDC__
171//
172// buggy is_convertible prevents working
173// implementation of is_enum:
174BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_enum,T,false)
175
176#endif
177
178#else // BOOST_IS_ENUM
179
180BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_enum,T,BOOST_IS_ENUM(T))
181
182#endif
183
184} // namespace boost
185
186#include <boost/type_traits/detail/bool_trait_undef.hpp>
187
188#endif // BOOST_TT_IS_ENUM_HPP_INCLUDED
189