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slice.hpp
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1
2// Range v3 library
3//
4// Copyright Eric Niebler 2013-present
5//
6// Use, modification and distribution is subject to the
7// Boost Software License, Version 1.0. (See accompanying
8// file LICENSE_1_0.txt or copy at
9// http://www.boost.org/LICENSE_1_0.txt)
10//
11// Project home: https://github.com/ericniebler/range-v3
12//
13
14#ifndef RANGES_V3_ACTION_SLICE_HPP
15#define RANGES_V3_ACTION_SLICE_HPP
16
17#include <meta/meta.hpp>
18
20
27#include <range/v3/utility/static_const.hpp>
29
30#include <range/v3/detail/prologue.hpp>
31
32namespace ranges
33{
36 namespace actions
37 {
38 struct slice_fn
39 {
40 private:
41 template<typename D>
42 using diff_t = range_difference_t<D>;
43
44 public:
45 // Overloads for the pipe syntax: rng | actions::slice(from, to)
46 template(typename D)(
47 requires integral<D>)
48 constexpr auto operator()(D from, D to) const
49 {
50 return make_action_closure(bind_back(slice_fn{}, from, to));
51 }
52 template(typename D)(
53 requires integral<D>)
54 constexpr auto operator()(D from, detail::from_end_<D> to) const
55 {
56 return make_action_closure(bind_back(slice_fn{}, from, to));
57 }
58 template(typename D)(
59 requires integral<D>)
60 constexpr auto operator()(detail::from_end_<D> from, detail::from_end_<D> to)
61 const
62 {
63 return make_action_closure(bind_back(slice_fn{}, from, to));
64 }
65 template(typename D)(
66 requires integral<D>)
67 constexpr auto operator()(D from, end_fn const & to) const
68 {
69 return make_action_closure(bind_back(slice_fn{}, from, to));
70 }
71 template(typename D)(
72 requires integral<D>)
73 constexpr auto operator()(detail::from_end_<D> from, end_fn const & to) const
74 {
75 return make_action_closure(bind_back(slice_fn{}, from, to));
76 }
77
78 template(typename Rng, typename I = iterator_t<Rng>)(
80 Rng operator()(Rng && rng, diff_t<Rng> from, diff_t<Rng> to) const
81 {
82 RANGES_EXPECT(0 <= from && 0 <= to && from <= to);
83 RANGES_EXPECT(!sized_range<Rng> || to <= distance(rng));
84 ranges::actions::erase(rng, begin(rng), next(begin(rng), from));
85 ranges::actions::erase(rng, next(begin(rng), to - from), end(rng));
86 return static_cast<Rng &&>(rng);
87 }
88
89 template(typename Rng, typename I = iterator_t<Rng>)(
91 Rng operator()(Rng && rng,
92 diff_t<Rng> from,
93 detail::from_end_<diff_t<Rng>> to) const
94 {
95 RANGES_EXPECT(0 <= from && to.dist_ <= 0);
96 RANGES_EXPECT(!sized_range<Rng> || from - to.dist_ <= distance(rng));
97 ranges::actions::erase(rng, begin(rng), next(begin(rng), from));
98 if(to.dist_ != 0)
99 {
100 auto const last = next(begin(rng), end(rng));
101 ranges::actions::erase(rng, prev(last, -to.dist_), last);
102 }
103 return static_cast<Rng &&>(rng);
104 }
105
106 template(typename Rng, typename I = iterator_t<Rng>)(
108 Rng operator()(Rng && rng,
109 detail::from_end_<diff_t<Rng>> from,
110 detail::from_end_<diff_t<Rng>> to) const
111 {
112 RANGES_EXPECT(from.dist_ <= 0 && to.dist_ <= 0 && from.dist_ <= to.dist_);
113 RANGES_EXPECT(!sized_range<Rng> || 0 <= distance(rng) + from.dist_);
114 auto last = next(begin(rng), end(rng));
115 ranges::actions::erase(rng, prev(last, -to.dist_), last);
116 last = next(begin(rng), end(rng));
117 ranges::actions::erase(
118 rng, begin(rng), prev(last, to.dist_ - from.dist_));
119 return static_cast<Rng &&>(rng);
120 }
121
122 template(typename Rng, typename I = iterator_t<Rng>)(
124 Rng operator()(Rng && rng, diff_t<Rng> from, end_fn const &) const
125 {
126 RANGES_EXPECT(0 <= from);
127 RANGES_EXPECT(!sized_range<Rng> || from <= distance(rng));
128 ranges::actions::erase(rng, begin(rng), next(begin(rng), from));
129 return static_cast<Rng &&>(rng);
130 }
131
132 template(typename Rng, typename I = iterator_t<Rng>)(
134 Rng operator()(Rng && rng,
135 detail::from_end_<diff_t<Rng>> from,
136 end_fn const &) const
137 {
138 RANGES_EXPECT(from.dist_ <= 0);
139 RANGES_EXPECT(!sized_range<Rng> || 0 <= distance(rng) + from.dist_);
140 auto const last = next(begin(rng), end(rng));
141 ranges::actions::erase(rng, begin(rng), prev(last, -from.dist_));
142 return static_cast<Rng &&>(rng);
143 }
144 };
145
147 RANGES_INLINE_VARIABLE(slice_fn, slice)
148 } // namespace actions
150} // namespace ranges
151
152#include <range/v3/detail/epilogue.hpp>
153
154#endif
The bidirectional_range concept.
The erasable_range concept.
The forward_range concept.
The sized_range concept.
decltype(begin(declval(Rng &))) iterator_t
Definition access.hpp:698
Tiny meta-programming library.
Definition slice.hpp:39