DUNE PDELab (git)

indices.hh
1// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2// vi: set et ts=4 sw=2 sts=2:
3// SPDX-FileCopyrightInfo: Copyright © DUNE Project contributors, see file LICENSE.md in module root
4// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
5
6#ifndef DUNE_COMMON_INDICES_HH
7#define DUNE_COMMON_INDICES_HH
8
9#include <cstddef>
10#include <stdexcept>
11#include <type_traits>
12#include <utility>
13
14namespace Dune
15{
28 template<std::size_t i>
29 using index_constant = std::integral_constant<std::size_t, i>;
30
31
32
49 namespace Indices
50 {
52 inline constexpr index_constant< 0> _0 = {};
53
55 inline constexpr index_constant< 1> _1 = {};
56
58 inline constexpr index_constant< 2> _2 = {};
59
61 inline constexpr index_constant< 3> _3 = {};
62
64 inline constexpr index_constant< 4> _4 = {};
65
67 inline constexpr index_constant< 5> _5 = {};
68
70 inline constexpr index_constant< 6> _6 = {};
71
73 inline constexpr index_constant< 7> _7 = {};
74
76 inline constexpr index_constant< 8> _8 = {};
77
79 inline constexpr index_constant< 9> _9 = {};
80
82 inline constexpr index_constant<10> _10 = {};
83
85 inline constexpr index_constant<11> _11 = {};
86
88 inline constexpr index_constant<12> _12 = {};
89
91 inline constexpr index_constant<13> _13 = {};
92
94 inline constexpr index_constant<14> _14 = {};
95
97 inline constexpr index_constant<15> _15 = {};
98
100 inline constexpr index_constant<16> _16 = {};
101
103 inline constexpr index_constant<17> _17 = {};
104
106 inline constexpr index_constant<18> _18 = {};
107
109 inline constexpr index_constant<19> _19 = {};
110
111 } // namespace Indices
112
123 template<class F, class I, I... i>
124 decltype(auto) constexpr unpackIntegerSequence(F&& f, std::integer_sequence<I, i...> sequence)
125 {
126 return f(std::integral_constant<I, i>()...);
127 }
128
129
130 namespace Indices { inline namespace Literals
131 {
132 namespace Impl
133 {
134 // convert a single character into an unsigned integer
135 constexpr unsigned char2digit (const char c)
136 {
137 if (c >= '0' && c <= '9')
138 return unsigned(c) - unsigned('0');
139 else {
140 throw std::invalid_argument("Character is not a digit.");
141 return 0u;
142 }
143 }
144
145 // convert a sequence of character digits into an unsigned integer
146 template <class T, char... digits>
147 constexpr T chars2number ()
148 {
149 const char arr[] = {digits...};
150 T result = 0;
151 T power = 1;
152 const T base = 10;
153
154 const int N = sizeof...(digits);
155 for (int i = 0; i < N; ++i) {
156 char c = arr[N - 1 - i];
157 result+= char2digit(c) * power;
158 power *= base;
159 }
160
161 return result;
162 }
163
164 } //namespace Impl
165
172 template <char... digits>
173 constexpr auto operator"" _ic()
174 {
175 return std::integral_constant<std::size_t, Impl::chars2number<std::size_t,digits...>()>{};
176 }
177
184 template <char... digits>
185 constexpr auto operator"" _uc()
186 {
187 return std::integral_constant<unsigned, Impl::chars2number<unsigned,digits...>()>{};
188 }
189
196 template <char... digits>
197 constexpr auto operator"" _sc()
198 {
199 return std::integral_constant<int, Impl::chars2number<int,digits...>()>{};
200 }
201
208 template <class T, T value>
209 constexpr auto operator- (std::integral_constant<T,value>)
210 {
211 return std::integral_constant<std::make_signed_t<T>, -value>{};
212 }
213
214 }} //namespace Indices::Literals
215} //namespace Dune
216
217#endif // DUNE_COMMON_INDICES_HH
constexpr index_constant< 16 > _16
Compile time index with value 16.
Definition: indices.hh:100
constexpr index_constant< 15 > _15
Compile time index with value 15.
Definition: indices.hh:97
constexpr index_constant< 8 > _8
Compile time index with value 8.
Definition: indices.hh:76
constexpr index_constant< 7 > _7
Compile time index with value 7.
Definition: indices.hh:73
constexpr index_constant< 0 > _0
Compile time index with value 0.
Definition: indices.hh:52
constexpr index_constant< 9 > _9
Compile time index with value 9.
Definition: indices.hh:79
constexpr index_constant< 14 > _14
Compile time index with value 14.
Definition: indices.hh:94
constexpr index_constant< 1 > _1
Compile time index with value 1.
Definition: indices.hh:55
constexpr index_constant< 3 > _3
Compile time index with value 3.
Definition: indices.hh:61
constexpr index_constant< 12 > _12
Compile time index with value 12.
Definition: indices.hh:88
decltype(auto) constexpr unpackIntegerSequence(F &&f, std::integer_sequence< I, i... > sequence)
Unpack an std::integer_sequence<I,i...> to std::integral_constant<I,i>...
Definition: indices.hh:124
constexpr auto operator-(std::integral_constant< T, value >)
Negation operator for integral constants.
Definition: indices.hh:209
constexpr index_constant< 11 > _11
Compile time index with value 11.
Definition: indices.hh:85
constexpr index_constant< 18 > _18
Compile time index with value 18.
Definition: indices.hh:106
constexpr index_constant< 13 > _13
Compile time index with value 13.
Definition: indices.hh:91
constexpr index_constant< 5 > _5
Compile time index with value 5.
Definition: indices.hh:67
constexpr index_constant< 17 > _17
Compile time index with value 17.
Definition: indices.hh:103
constexpr index_constant< 10 > _10
Compile time index with value 10.
Definition: indices.hh:82
constexpr index_constant< 2 > _2
Compile time index with value 2.
Definition: indices.hh:58
std::integral_constant< std::size_t, i > index_constant
An index constant with value i.
Definition: indices.hh:29
constexpr index_constant< 19 > _19
Compile time index with value 19.
Definition: indices.hh:109
constexpr index_constant< 6 > _6
Compile time index with value 6.
Definition: indices.hh:70
constexpr index_constant< 4 > _4
Compile time index with value 4.
Definition: indices.hh:64
Namespace with predefined compile time indices for the range [0,19].
Definition: indices.hh:50
Dune namespace.
Definition: alignedallocator.hh:13
constexpr Base power(Base m, Exponent p)
Power method for integer exponents.
Definition: math.hh:75
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