1/*!
2@file
3Forward declares `boost::hana::integral_constant`.
4
5Copyright Louis Dionne 2013-2022
6Distributed under the Boost Software License, Version 1.0.
7(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
8 */
9
10#ifndef BOOST_HANA_FWD_INTEGRAL_CONSTANT_HPP
11#define BOOST_HANA_FWD_INTEGRAL_CONSTANT_HPP
12
13#include <boost/hana/config.hpp>
14#include <boost/hana/detail/integral_constant.hpp>
15
16#include <cstddef>
17
18
19namespace boost { namespace hana {
20 //! Creates an `integral_constant` holding the given compile-time value.
21 //! @relates hana::integral_constant
22 //!
23 //! Specifically, `integral_c<T, v>` is a `hana::integral_constant`
24 //! holding the compile-time value `v` of an integral type `T`.
25 //!
26 //!
27 //! @tparam T
28 //! The type of the value to hold in the `integral_constant`.
29 //! It must be an integral type.
30 //!
31 //! @tparam v
32 //! The integral value to hold in the `integral_constant`.
33 //!
34 //!
35 //! Example
36 //! -------
37 //! @snippet example/integral_constant.cpp integral_c
38 template <typename T, T v>
39 BOOST_HANA_INLINE_VARIABLE constexpr integral_constant<T, v> integral_c{};
40
41
42 //! @relates hana::integral_constant
43 template <bool b>
44 using bool_ = integral_constant<bool, b>;
45
46 //! @relates hana::integral_constant
47 template <bool b>
48 BOOST_HANA_INLINE_VARIABLE constexpr bool_<b> bool_c{};
49
50 //! @relates hana::integral_constant
51 using true_ = bool_<true>;
52
53 //! @relates hana::integral_constant
54 BOOST_HANA_INLINE_VARIABLE constexpr auto true_c = bool_c<true>;
55
56 //! @relates hana::integral_constant
57 using false_ = bool_<false>;
58
59 //! @relates hana::integral_constant
60 BOOST_HANA_INLINE_VARIABLE constexpr auto false_c = bool_c<false>;
61
62
63 //! @relates hana::integral_constant
64 template <char c>
65 using char_ = integral_constant<char, c>;
66
67 //! @relates hana::integral_constant
68 template <char c>
69 BOOST_HANA_INLINE_VARIABLE constexpr char_<c> char_c{};
70
71
72 //! @relates hana::integral_constant
73 template <short i>
74 using short_ = integral_constant<short, i>;
75
76 //! @relates hana::integral_constant
77 template <short i>
78 BOOST_HANA_INLINE_VARIABLE constexpr short_<i> short_c{};
79
80
81 //! @relates hana::integral_constant
82 template <unsigned short i>
83 using ushort_ = integral_constant<unsigned short, i>;
84
85 //! @relates hana::integral_constant
86 template <unsigned short i>
87 BOOST_HANA_INLINE_VARIABLE constexpr ushort_<i> ushort_c{};
88
89
90 //! @relates hana::integral_constant
91 template <int i>
92 using int_ = integral_constant<int, i>;
93
94 //! @relates hana::integral_constant
95 template <int i>
96 BOOST_HANA_INLINE_VARIABLE constexpr int_<i> int_c{};
97
98
99 //! @relates hana::integral_constant
100 template <unsigned int i>
101 using uint = integral_constant<unsigned int, i>;
102
103 //! @relates hana::integral_constant
104 template <unsigned int i>
105 BOOST_HANA_INLINE_VARIABLE constexpr uint<i> uint_c{};
106
107
108 //! @relates hana::integral_constant
109 template <long i>
110 using long_ = integral_constant<long, i>;
111
112 //! @relates hana::integral_constant
113 template <long i>
114 BOOST_HANA_INLINE_VARIABLE constexpr long_<i> long_c{};
115
116
117 //! @relates hana::integral_constant
118 template <unsigned long i>
119 using ulong = integral_constant<unsigned long, i>;
120
121 //! @relates hana::integral_constant
122 template <unsigned long i>
123 BOOST_HANA_INLINE_VARIABLE constexpr ulong<i> ulong_c{};
124
125
126 //! @relates hana::integral_constant
127 template <long long i>
128 using llong = integral_constant<long long, i>;
129
130 //! @relates hana::integral_constant
131 template <long long i>
132 BOOST_HANA_INLINE_VARIABLE constexpr llong<i> llong_c{};
133
134
135 //! @relates hana::integral_constant
136 template <unsigned long long i>
137 using ullong = integral_constant<unsigned long long, i>;
138
139 //! @relates hana::integral_constant
140 template <unsigned long long i>
141 BOOST_HANA_INLINE_VARIABLE constexpr ullong<i> ullong_c{};
142
143
144 //! @relates hana::integral_constant
145 template <std::size_t i>
146 using size_t = integral_constant<std::size_t, i>;
147
148 //! @relates hana::integral_constant
149 template <std::size_t i>
150 BOOST_HANA_INLINE_VARIABLE constexpr size_t<i> size_c{};
151
152
153 namespace literals {
154 //! Creates a `hana::integral_constant` from a literal.
155 //! @relatesalso boost::hana::integral_constant
156 //!
157 //! The literal is parsed at compile-time and the result is returned
158 //! as a `llong<...>`.
159 //!
160 //! @note
161 //! We use `llong<...>` instead of `ullong<...>` because using an
162 //! unsigned type leads to unexpected behavior when doing stuff like
163 //! `-1_c`. If we used an unsigned type, `-1_c` would be something
164 //! like `ullong<-1>` which is actually `ullong<something huge>`.
165 //!
166 //!
167 //! Example
168 //! -------
169 //! @snippet example/integral_constant.cpp literals
170 template <char ...c>
171 constexpr auto operator"" _c();
172 }
173}} // end namespace boost::hana
174
175#endif // !BOOST_HANA_FWD_INTEGRAL_CONSTANT_HPP
176

source code of boost/libs/hana/include/boost/hana/fwd/integral_constant.hpp