1/*!
2@file
3Defines `boost::hana::detail::variadic::foldl1`.
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_DETAIL_VARIADIC_FOLDL1_HPP
11#define BOOST_HANA_DETAIL_VARIADIC_FOLDL1_HPP
12
13#include <boost/hana/config.hpp>
14#include <boost/hana/core/when.hpp>
15
16
17namespace boost { namespace hana { namespace detail { namespace variadic {
18 //! @cond
19 template <unsigned int n, typename = when<true>>
20 struct foldl1_impl;
21
22 template <>
23 struct foldl1_impl<1> {
24 template <typename F, typename X1>
25 static constexpr X1 apply(F&&, X1&& x1)
26 { return static_cast<X1&&>(x1); }
27 };
28
29 template <>
30 struct foldl1_impl<2> {
31 template <typename F, typename X1, typename X2>
32 static constexpr decltype(auto) apply(F&& f, X1&& x1, X2&& x2) {
33 return static_cast<F&&>(f)(static_cast<X1&&>(x1),
34 static_cast<X2&&>(x2));
35 }
36 };
37
38 template <>
39 struct foldl1_impl<3> {
40 template <typename F, typename X1, typename X2, typename X3>
41 static constexpr decltype(auto) apply(F&& f, X1&& x1, X2&& x2, X3&& x3) {
42 return f(f(static_cast<X1&&>(x1),
43 static_cast<X2&&>(x2)),
44 static_cast<X3&&>(x3));
45 }
46 };
47
48 template <>
49 struct foldl1_impl<4> {
50 template <typename F, typename X1, typename X2, typename X3, typename X4>
51 static constexpr decltype(auto) apply(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4) {
52 return f(f(f(static_cast<X1&&>(x1),
53 static_cast<X2&&>(x2)),
54 static_cast<X3&&>(x3)),
55 static_cast<X4&&>(x4));
56 }
57 };
58
59 template <>
60 struct foldl1_impl<5> {
61 template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5>
62 static constexpr decltype(auto) apply(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5) {
63 return f(f(f(f(static_cast<X1&&>(x1),
64 static_cast<X2&&>(x2)),
65 static_cast<X3&&>(x3)),
66 static_cast<X4&&>(x4)),
67 static_cast<X5&&>(x5));
68 }
69 };
70
71 template <>
72 struct foldl1_impl<6> {
73 template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5, typename X6>
74 static constexpr decltype(auto) apply(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6) {
75 return f(f(f(f(f(static_cast<X1&&>(x1),
76 static_cast<X2&&>(x2)),
77 static_cast<X3&&>(x3)),
78 static_cast<X4&&>(x4)),
79 static_cast<X5&&>(x5)),
80 static_cast<X6&&>(x6));
81 }
82 };
83
84 template <unsigned int n>
85 struct foldl1_impl<n, when<(n >= 7) && (n < 14)>> {
86 template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename X7, typename ...Xn>
87 static constexpr decltype(auto)
88 apply(F&& f
89 , X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, X7&& x7
90 , Xn&& ...xn)
91 {
92 return foldl1_impl<sizeof...(xn) + 1>::apply(
93 f,
94 f(f(f(f(f(f(static_cast<X1&&>(x1),
95 static_cast<X2&&>(x2)),
96 static_cast<X3&&>(x3)),
97 static_cast<X4&&>(x4)),
98 static_cast<X5&&>(x5)),
99 static_cast<X6&&>(x6)),
100 static_cast<X7&&>(x7)),
101 static_cast<Xn&&>(xn)...
102 );
103 }
104 };
105
106 template <unsigned int n>
107 struct foldl1_impl<n, when<(n >= 14) && (n < 28)>> {
108 template <
109 typename F
110 , typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename X7
111 , typename X8, typename X9, typename X10, typename X11, typename X12, typename X13, typename X14
112 , typename ...Xn
113 >
114 static constexpr decltype(auto)
115 apply(F&& f
116 , X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, X7&& x7
117 , X8&& x8, X9&& x9, X10&& x10, X11&& x11, X12&& x12, X13&& x13, X14&& x14
118 , Xn&& ...xn)
119 {
120 return foldl1_impl<sizeof...(xn) + 1>::apply(
121 f,
122 f(f(f(f(f(f(f(f(f(f(f(f(f(
123 static_cast<X1&&>(x1), static_cast<X2&&>(x2)), static_cast<X3&&>(x3)), static_cast<X4&&>(x4)), static_cast<X5&&>(x5)), static_cast<X6&&>(x6)), static_cast<X7&&>(x7)),
124 static_cast<X8&&>(x8)), static_cast<X9&&>(x9)), static_cast<X10&&>(x10)), static_cast<X11&&>(x11)), static_cast<X12&&>(x12)), static_cast<X13&&>(x13)), static_cast<X14&&>(x14))
125 , static_cast<Xn&&>(xn)...);
126
127 }
128 };
129
130 template <unsigned int n>
131 struct foldl1_impl<n, when<(n >= 28) && (n < 56)>> {
132 template <
133 typename F
134 , typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename X7
135 , typename X8, typename X9, typename X10, typename X11, typename X12, typename X13, typename X14
136 , typename X15, typename X16, typename X17, typename X18, typename X19, typename X20, typename X21
137 , typename X22, typename X23, typename X24, typename X25, typename X26, typename X27, typename X28
138 , typename ...Xn
139 >
140 static constexpr decltype(auto)
141 apply(F&& f
142 , X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, X7&& x7
143 , X8&& x8, X9&& x9, X10&& x10, X11&& x11, X12&& x12, X13&& x13, X14&& x14
144 , X15&& x15, X16&& x16, X17&& x17, X18&& x18, X19&& x19, X20&& x20, X21&& x21
145 , X22&& x22, X23&& x23, X24&& x24, X25&& x25, X26&& x26, X27&& x27, X28&& x28
146 , Xn&& ...xn)
147 {
148 return foldl1_impl<sizeof...(xn) + 1>::apply(
149 f,
150 f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(
151 static_cast<X1&&>(x1), static_cast<X2&&>(x2)), static_cast<X3&&>(x3)), static_cast<X4&&>(x4)), static_cast<X5&&>(x5)), static_cast<X6&&>(x6)), static_cast<X7&&>(x7)),
152 static_cast<X8&&>(x8)), static_cast<X9&&>(x9)), static_cast<X10&&>(x10)), static_cast<X11&&>(x11)), static_cast<X12&&>(x12)), static_cast<X13&&>(x13)), static_cast<X14&&>(x14)),
153 static_cast<X15&&>(x15)), static_cast<X16&&>(x16)), static_cast<X17&&>(x17)), static_cast<X18&&>(x18)), static_cast<X19&&>(x19)), static_cast<X20&&>(x20)), static_cast<X21&&>(x21)),
154 static_cast<X22&&>(x22)), static_cast<X23&&>(x23)), static_cast<X24&&>(x24)), static_cast<X25&&>(x25)), static_cast<X26&&>(x26)), static_cast<X27&&>(x27)), static_cast<X28&&>(x28))
155 , static_cast<Xn&&>(xn)...);
156 }
157 };
158
159 template <unsigned int n>
160 struct foldl1_impl<n, when<(n >= 56)>> {
161 template <
162 typename F
163 , typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename X7
164 , typename X8, typename X9, typename X10, typename X11, typename X12, typename X13, typename X14
165 , typename X15, typename X16, typename X17, typename X18, typename X19, typename X20, typename X21
166 , typename X22, typename X23, typename X24, typename X25, typename X26, typename X27, typename X28
167 , typename X29, typename X30, typename X31, typename X32, typename X33, typename X34, typename X35
168 , typename X36, typename X37, typename X38, typename X39, typename X40, typename X41, typename X42
169 , typename X43, typename X44, typename X45, typename X46, typename X47, typename X48, typename X49
170 , typename X50, typename X51, typename X52, typename X53, typename X54, typename X55, typename X56
171 , typename ...Xn
172 >
173 static constexpr decltype(auto)
174 apply(F&& f
175 , X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, X7&& x7
176 , X8&& x8, X9&& x9, X10&& x10, X11&& x11, X12&& x12, X13&& x13, X14&& x14
177 , X15&& x15, X16&& x16, X17&& x17, X18&& x18, X19&& x19, X20&& x20, X21&& x21
178 , X22&& x22, X23&& x23, X24&& x24, X25&& x25, X26&& x26, X27&& x27, X28&& x28
179 , X29&& x29, X30&& x30, X31&& x31, X32&& x32, X33&& x33, X34&& x34, X35&& x35
180 , X36&& x36, X37&& x37, X38&& x38, X39&& x39, X40&& x40, X41&& x41, X42&& x42
181 , X43&& x43, X44&& x44, X45&& x45, X46&& x46, X47&& x47, X48&& x48, X49&& x49
182 , X50&& x50, X51&& x51, X52&& x52, X53&& x53, X54&& x54, X55&& x55, X56&& x56
183 , Xn&& ...xn)
184 {
185 return foldl1_impl<sizeof...(xn) + 1>::apply(
186 f,
187 f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(f(
188 static_cast<X1&&>(x1), static_cast<X2&&>(x2)), static_cast<X3&&>(x3)), static_cast<X4&&>(x4)), static_cast<X5&&>(x5)), static_cast<X6&&>(x6)), static_cast<X7&&>(x7)),
189 static_cast<X8&&>(x8)), static_cast<X9&&>(x9)), static_cast<X10&&>(x10)), static_cast<X11&&>(x11)), static_cast<X12&&>(x12)), static_cast<X13&&>(x13)), static_cast<X14&&>(x14)),
190 static_cast<X15&&>(x15)), static_cast<X16&&>(x16)), static_cast<X17&&>(x17)), static_cast<X18&&>(x18)), static_cast<X19&&>(x19)), static_cast<X20&&>(x20)), static_cast<X21&&>(x21)),
191 static_cast<X22&&>(x22)), static_cast<X23&&>(x23)), static_cast<X24&&>(x24)), static_cast<X25&&>(x25)), static_cast<X26&&>(x26)), static_cast<X27&&>(x27)), static_cast<X28&&>(x28)),
192 static_cast<X29&&>(x29)), static_cast<X30&&>(x30)), static_cast<X31&&>(x31)), static_cast<X32&&>(x32)), static_cast<X33&&>(x33)), static_cast<X34&&>(x34)), static_cast<X35&&>(x35)),
193 static_cast<X36&&>(x36)), static_cast<X37&&>(x37)), static_cast<X38&&>(x38)), static_cast<X39&&>(x39)), static_cast<X40&&>(x40)), static_cast<X41&&>(x41)), static_cast<X42&&>(x42)),
194 static_cast<X43&&>(x43)), static_cast<X44&&>(x44)), static_cast<X45&&>(x45)), static_cast<X46&&>(x46)), static_cast<X47&&>(x47)), static_cast<X48&&>(x48)), static_cast<X49&&>(x49)),
195 static_cast<X50&&>(x50)), static_cast<X51&&>(x51)), static_cast<X52&&>(x52)), static_cast<X53&&>(x53)), static_cast<X54&&>(x54)), static_cast<X55&&>(x55)), static_cast<X56&&>(x56))
196 , static_cast<Xn&&>(xn)...);
197 }
198 };
199 //! @endcond
200
201 struct foldl1_t {
202 template <typename F, typename X1, typename ...Xn>
203 constexpr decltype(auto) operator()(F&& f, X1&& x1, Xn&& ...xn) const {
204 return foldl1_impl<sizeof...(xn) + 1>::apply(
205 static_cast<F&&>(f), static_cast<X1&&>(x1), static_cast<Xn&&>(xn)...
206 );
207 }
208 };
209
210 BOOST_HANA_INLINE_VARIABLE constexpr foldl1_t foldl1{};
211 BOOST_HANA_INLINE_VARIABLE constexpr auto foldl = foldl1;
212}} }} // end namespace boost::hana
213
214#endif // !BOOST_HANA_DETAIL_VARIADIC_FOLDL1_HPP
215

source code of boost/libs/hana/include/boost/hana/detail/variadic/foldl1.hpp