/usr/include/range/v3/view/intersperse.hpp is in librange-v3-dev 0.3.5-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 | /// \file
// Range v3 library
//
// Copyright Eric Niebler 2013-present
//
// Use, modification and distribution is subject to the
// Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ericniebler/range-v3
//
#ifndef RANGES_V3_VIEW_INTERSPERSE_HPP
#define RANGES_V3_VIEW_INTERSPERSE_HPP
#include <type_traits>
#include <utility>
#include <meta/meta.hpp>
#include <range/v3/begin_end.hpp>
#include <range/v3/iterator_range.hpp>
#include <range/v3/range_fwd.hpp>
#include <range/v3/range_concepts.hpp>
#include <range/v3/range_traits.hpp>
#include <range/v3/size.hpp>
#include <range/v3/view_adaptor.hpp>
#include <range/v3/detail/satisfy_boost_range.hpp>
#include <range/v3/utility/iterator.hpp>
#include <range/v3/utility/functional.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/view/view.hpp>
namespace ranges
{
inline namespace v3
{
/// \addtogroup group-views
/// @{
template<typename Rng>
struct intersperse_view
: view_adaptor<
intersperse_view<Rng>,
Rng,
(range_cardinality<Rng>::value > 0) ?
static_cast<cardinality>(range_cardinality<Rng>::value * 2 - 1) :
range_cardinality<Rng>::value>
{
intersperse_view() = default;
constexpr intersperse_view(Rng rng, range_value_type_t<Rng> val)
noexcept(
std::is_nothrow_constructible<
typename intersperse_view::view_adaptor, Rng>::value &&
std::is_nothrow_move_constructible<range_value_type_t<Rng>>::value)
: intersperse_view::view_adaptor{detail::move(rng)}, val_(detail::move(val))
{}
CONCEPT_REQUIRES(SizedRange<Rng const>())
constexpr range_size_type_t<Rng> size() const
noexcept(noexcept(ranges::size(std::declval<Rng const &>())))
{
return size_(ranges::size(this->base()));
}
CONCEPT_REQUIRES(!SizedRange<Rng const>() && SizedRange<Rng>())
RANGES_CXX14_CONSTEXPR range_size_type_t<Rng> size()
noexcept(noexcept(ranges::size(std::declval<Rng &>())))
{
return size_(ranges::size(this->base()));
}
private:
friend range_access;
struct cursor_adaptor : adaptor_base
{
cursor_adaptor() = default;
explicit constexpr cursor_adaptor(intersperse_view const &view)
noexcept(std::is_nothrow_copy_constructible<range_value_type_t<Rng>>::value)
: val_{view.val_}
{}
template<typename View>
RANGES_CXX14_CONSTEXPR iterator_t<Rng> begin(View &view)
noexcept(std::is_nothrow_move_constructible<iterator_t<Rng>>::value &&
noexcept(ranges::begin(view.base()) != ranges::end(view.base())))
{
auto first = ranges::begin(view.base());
toggle_ = first != ranges::end(view.base());
return first;
}
constexpr range_value_type_t<Rng> read(iterator_t<Rng> const &it) const
noexcept(noexcept(range_value_type_t<Rng>(*it)) &&
std::is_nothrow_copy_constructible<range_value_type_t<Rng>>::value)
{
return toggle_ ? *it : val_;
}
CONCEPT_REQUIRES(Sentinel<iterator_t<Rng>, iterator_t<Rng>>())
constexpr bool equal(iterator_t<Rng> const &it0, iterator_t<Rng> const &it1,
cursor_adaptor const &other) const
noexcept(noexcept(it0 == it1))
{
return it0 == it1 && toggle_ == other.toggle_;
}
RANGES_CXX14_CONSTEXPR void next(iterator_t<Rng> &it)
noexcept(noexcept(++it))
{
if(toggle_)
++it;
toggle_ = !toggle_;
}
CONCEPT_REQUIRES(BidirectionalRange<Rng>())
RANGES_CXX14_CONSTEXPR void prev(iterator_t<Rng> &it)
noexcept(noexcept(--it))
{
toggle_ = !toggle_;
if(toggle_)
--it;
}
CONCEPT_REQUIRES(SizedSentinel<iterator_t<Rng>, iterator_t<Rng>>())
constexpr range_difference_type_t<Rng> distance_to(iterator_t<Rng> const &it,
iterator_t<Rng> const &other_it, cursor_adaptor const &other) const
noexcept(noexcept(other_it - it))
{
return (other_it - it) * 2 + (other.toggle_ - toggle_);
}
CONCEPT_REQUIRES(RandomAccessRange<Rng>())
RANGES_CXX14_CONSTEXPR
void advance(iterator_t<Rng> &it, range_difference_type_t<Rng> n)
noexcept(noexcept(ranges::advance(it, n)))
{
ranges::advance(it, n >= 0 ? (n + toggle_) / 2 : (n - !toggle_) / 2);
if(n % 2 != 0)
toggle_ = !toggle_;
}
private:
bool toggle_ = false;
range_value_type_t<Rng> val_;
};
struct sentinel_adaptor : adaptor_base
{
static constexpr bool empty(iterator_t<Rng> const &it,
cursor_adaptor const &, sentinel_t<Rng> const &sent)
RANGES_AUTO_RETURN_NOEXCEPT
(
it == sent
)
};
CONCEPT_REQUIRES(Range<Rng const>())
constexpr cursor_adaptor begin_adaptor() const
noexcept(std::is_nothrow_constructible<
cursor_adaptor, intersperse_view const&>::value)
{
return cursor_adaptor{*this};
}
CONCEPT_REQUIRES(!Range<Rng const>())
RANGES_CXX14_CONSTEXPR cursor_adaptor begin_adaptor()
noexcept(std::is_nothrow_constructible<
cursor_adaptor, intersperse_view &>::value)
{
return cursor_adaptor{*this};
}
CONCEPT_REQUIRES(Range<Rng const>() && BoundedRange<Rng>() &&
!SinglePass<iterator_t<Rng>>())
constexpr cursor_adaptor end_adaptor() const
noexcept(std::is_nothrow_constructible<
cursor_adaptor, intersperse_view const&>::value)
{
return cursor_adaptor{*this};
}
CONCEPT_REQUIRES(!Range<Rng const>() && BoundedRange<Rng>() &&
!SinglePass<iterator_t<Rng>>())
RANGES_CXX14_CONSTEXPR cursor_adaptor end_adaptor()
noexcept(std::is_nothrow_constructible<
cursor_adaptor, intersperse_view &>::value)
{
return cursor_adaptor{*this};
}
CONCEPT_REQUIRES(!BoundedRange<Rng>() || SinglePass<iterator_t<Rng>>())
constexpr sentinel_adaptor end_adaptor() const noexcept
{
return {};
}
constexpr range_size_type_t<Rng> size_(range_size_type_t<Rng> const n) const noexcept
{
return n ? n * 2 - 1 : 0;
}
range_value_type_t<Rng> val_;
};
namespace view
{
struct intersperse_fn
{
private:
friend view_access;
template<typename T, CONCEPT_REQUIRES_(Copyable<T>())>
static auto bind(intersperse_fn intersperse, T t)
RANGES_DECLTYPE_AUTO_RETURN_NOEXCEPT
(
make_pipeable(std::bind(intersperse, std::placeholders::_1, std::move(t)))
)
public:
template<typename Rng, typename T = range_value_type_t<Rng>>
using Constraint = meta::and_<
InputRange<Rng>,
ConvertibleTo<T, range_value_type_t<Rng>>,
ConvertibleTo<range_reference_t<Rng>, range_value_type_t<Rng>>,
SemiRegular<range_value_type_t<Rng>>>;
template<typename Rng,
CONCEPT_REQUIRES_(Constraint<Rng>())>
constexpr auto operator()(Rng &&rng, range_value_type_t<Rng> val) const
RANGES_DECLTYPE_AUTO_RETURN_NOEXCEPT
(
intersperse_view<all_t<Rng>>{all(static_cast<Rng &&>(rng)), std::move(val)}
)
#ifndef RANGES_DOXYGEN_INVOKED
template<typename Rng, typename T,
CONCEPT_REQUIRES_(!Constraint<Rng, T>())>
void operator()(Rng &&, T &&) const
{
CONCEPT_ASSERT_MSG(InputRange<Rng>(),
"The object on which view::intersperse operates must be a model of the "
"InputRange concept.");
using V = range_value_type_t<Rng>;
CONCEPT_ASSERT_MSG(ConvertibleTo<T, V>(),
"The value to intersperse in the range must be convertible to the range's "
"value type.");
CONCEPT_ASSERT_MSG(ConvertibleTo<range_reference_t<Rng>, V>(),
"The range's reference type must be convertible to the range's "
"value type.");
CONCEPT_ASSERT_MSG(SemiRegular<V>(),
"The range on which view::intersperse operates must have a value type that "
"models the SemiRegular concept; that is, it must be default constructible, "
"copy and move constructible, and destructible.");
}
#endif
};
/// \relates intersperse_fn
/// \ingroup group-views
RANGES_INLINE_VARIABLE(view<intersperse_fn>, intersperse)
}
}
}
RANGES_SATISFY_BOOST_RANGE(::ranges::v3::intersperse_view)
#endif
|