eedb/share/include/range/v3/iterator_range.hpp
Wieczorek Bartosz f4ef592706 add ranges lib
2017-03-18 08:15:40 +01:00

269 lines
9.1 KiB
C++

/// \file
// Range v3 library
//
// Copyright Eric Niebler 2013-2014
//
// 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_ITERATOR_RANGE_HPP
#define RANGES_V3_ITERATOR_RANGE_HPP
#include <utility>
#include <type_traits>
#include <meta/meta.hpp>
#include <range/v3/range_fwd.hpp>
#include <range/v3/distance.hpp>
#include <range/v3/view_interface.hpp>
#include <range/v3/utility/concepts.hpp>
#include <range/v3/utility/iterator.hpp>
#include <range/v3/utility/tagged_pair.hpp>
#include <range/v3/utility/iterator_concepts.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/algorithm/tagspec.hpp>
namespace ranges
{
inline namespace v3
{
/// \addtogroup group-core
/// @{
template<typename I, typename S /*= I*/>
struct iterator_range
: tagged_compressed_tuple<tag::begin(I), tag::end(S)>
, view_interface<iterator_range<I, S>>
{
private:
using base_t = tagged_compressed_tuple<tag::begin(I), tag::end(S)>;
public:
using iterator = I;
using sentinel = S;
#ifndef RANGES_DOXYGEN_INVOKED
using const_iterator = I; // Mostly to avoid spurious errors in Boost.Range
#endif
using base_t::begin;
using base_t::end;
iterator_range() = default;
constexpr iterator_range(I begin, S end)
: base_t{detail::move(begin), detail::move(end)}
{}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Constructible<I, X>() && Constructible<S, Y>())>
constexpr iterator_range(iterator_range<X, Y> rng)
: base_t{detail::move(rng.begin()), detail::move(rng.end())}
{}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Constructible<I, X>() && Constructible<S, Y>())>
explicit constexpr iterator_range(std::pair<X, Y> rng)
: base_t{detail::move(rng.first), detail::move(rng.second)}
{}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Assignable<I &, X>() && Assignable<S &, Y>())>
iterator_range &operator=(iterator_range<X, Y> rng)
{
begin() = detail::move(rng).begin();
end() = detail::move(rng).end();
return *this;
}
template<typename X, typename Y,
CONCEPT_REQUIRES_(ConvertibleTo<I, X>() && ConvertibleTo<S, Y>())>
constexpr operator std::pair<X, Y>() const
{
return {begin(), end()};
}
};
// Like iterator_range, but with a known size. The first and second members
// are private to prevent inadvertent violations of the class invariant.
//
// Class invariant:
// distance(begin(), end()) == size()
//
template<typename I, typename S /* = I */>
struct sized_iterator_range
: view_interface<sized_iterator_range<I, S>>
{
private:
template<typename X, typename Y>
friend struct sized_iterator_range;
iterator_range<I, S> rng_;
size_type_t<I> size_;
public:
using iterator = I;
using sentinel = S;
#ifndef RANGES_DOXYGEN_INVOKED
using const_iterator = I; // Mostly to avoid spurious errors in Boost.Range
#endif
sized_iterator_range() = default;
RANGES_NDEBUG_CONSTEXPR sized_iterator_range(I begin, S end, size_type_t<I> size)
: rng_{detail::move(begin), detail::move(end)}, size_(size)
{
#ifndef NDEBUG
RANGES_ASSERT(!ForwardIterator<I>() ||
static_cast<size_type_t<I>>(ranges::distance(rng_)) == size_);
#endif
}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Constructible<I, X>() && Constructible<S, Y>())>
RANGES_NDEBUG_CONSTEXPR sized_iterator_range(std::pair<X, Y> rng, size_type_t<I> size)
: sized_iterator_range{detail::move(rng).first, detail::move(rng).second, size}
{}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Constructible<I, X>() && Constructible<S, Y>())>
RANGES_NDEBUG_CONSTEXPR sized_iterator_range(iterator_range<X, Y> rng, size_type_t<I> size)
: sized_iterator_range{detail::move(rng).first(), detail::move(rng).second, size}
{}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Constructible<I, X>() && Constructible<S, Y>())>
RANGES_NDEBUG_CONSTEXPR sized_iterator_range(sized_iterator_range<X, Y> rng)
: sized_iterator_range{detail::move(rng).rng_.first(), detail::move(rng).rng_.second, rng.size_}
{}
template<typename X, typename Y,
CONCEPT_REQUIRES_(Assignable<I &, X>() && Assignable<S &, Y>())>
sized_iterator_range &operator=(sized_iterator_range<X, Y> rng)
{
rng_ = detail::move(rng).rng_;
size_ = rng.size_;
return *this;
}
I begin() const
{
return rng_.begin();
}
S end() const
{
return rng_.end();
}
size_type_t<I> size() const
{
return size_;
}
template<typename X, typename Y,
CONCEPT_REQUIRES_(ConvertibleTo<I, X>() && ConvertibleTo<S, Y>())>
constexpr operator std::pair<X, Y>() const
{
return rng_;
}
template<typename X, typename Y,
CONCEPT_REQUIRES_(ConvertibleTo<I, X>() && ConvertibleTo<S, Y>())>
constexpr operator iterator_range<X, Y>() const
{
return rng_;
}
constexpr operator iterator_range<I, S> const &() const & noexcept
{
return rng_;
}
};
struct make_iterator_range_fn
{
/// \return `{begin, end}`
template<typename I, typename S,
CONCEPT_REQUIRES_(Sentinel<S, I>())>
constexpr iterator_range<I, S> operator()(I begin, S end) const
{
CONCEPT_ASSERT(Sentinel<S, I>());
return {detail::move(begin), detail::move(end)};
}
/// \return `{begin, end, size}`
template<typename I, typename S,
CONCEPT_REQUIRES_(Sentinel<S, I>())>
constexpr sized_iterator_range<I, S> operator()(I begin, S end, size_type_t<I> size) const
{
CONCEPT_ASSERT(Sentinel<S, I>());
return {detail::move(begin), detail::move(end), size};
}
};
/// \ingroup group-core
/// \sa `make_iterator_range_fn`
RANGES_INLINE_VARIABLE(make_iterator_range_fn, make_iterator_range)
/// Tuple-like access for `sized_iterator_range`
template<std::size_t N, typename I, typename S,
CONCEPT_REQUIRES_(N < 2)>
constexpr auto get(sized_iterator_range<I, S> const &p)
RANGES_DECLTYPE_AUTO_RETURN
(
ranges::get<N>(static_cast<iterator_range<I, S> const &>(p))
)
/// \overload
template<std::size_t N, typename I, typename S,
CONCEPT_REQUIRES_(N == 2)>
constexpr size_type_t<I> get(sized_iterator_range<I, S> const &p)
{
return p.size();
}
// TODO add specialization of range_cardinality for when we can determine the range is infinite
/// @}
}
}
// The standard is inconsistent about whether these are classes or structs
RANGES_DIAGNOSTIC_PUSH
RANGES_DIAGNOSTIC_IGNORE_PRAGMAS
RANGES_DIAGNOSTIC_IGNORE_MISMATCHED_TAGS
/// \cond
namespace std
{
template<typename I, typename S>
struct tuple_size< ::ranges::v3::iterator_range<I, S>>
: std::integral_constant<size_t, 2>
{};
template<typename I, typename S>
struct tuple_element<0, ::ranges::v3::iterator_range<I, S>>
{
using type = I;
};
template<typename I, typename S>
struct tuple_element<1, ::ranges::v3::iterator_range<I, S>>
{
using type = S;
};
template<typename I, typename S>
struct tuple_size< ::ranges::v3::sized_iterator_range<I, S>>
: std::integral_constant<size_t, 3>
{};
template<typename I, typename S>
struct tuple_element<0, ::ranges::v3::sized_iterator_range<I, S>>
{
using type = I;
};
template<typename I, typename S>
struct tuple_element<1, ::ranges::v3::sized_iterator_range<I, S>>
{
using type = S;
};
template<typename I, typename S>
struct tuple_element<2, ::ranges::v3::sized_iterator_range<I, S>>
{
using type = ::ranges::v3::size_type_t<I>;
};
}
/// \endcond
RANGES_DIAGNOSTIC_POP
#endif