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/// \file
// Range v3 library
//
// Copyright Eric Niebler 2014-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_COUNTED_HPP
#define RANGES_V3_VIEW_COUNTED_HPP
#include <utility>
#include <range/v3/detail/satisfy_boost_range.hpp>
#include <range/v3/range_fwd.hpp>
#include <range/v3/view_interface.hpp>
#include <range/v3/iterator_range.hpp>
#include <range/v3/utility/iterator.hpp>
#include <range/v3/utility/iterator_traits.hpp>
#include <range/v3/utility/iterator_concepts.hpp>
#include <range/v3/utility/counted_iterator.hpp>
#include <range/v3/utility/static_const.hpp>
namespace ranges
{
inline namespace v3
{
/// \addtogroup group-views
/// @{
template<typename I>
struct counted_view
: view_interface<counted_view<I>>
{
private:
friend range_access;
using size_type_ = size_type_t<I>;
I it_;
difference_type_t<I> n_;
public:
counted_view() = default;
counted_view(I it, difference_type_t<I> n)
: it_(it), n_(n)
{
RANGES_EXPECT(0 <= n_);
}
counted_iterator<I> begin() const
{
return make_counted_iterator(it_, n_);
}
default_sentinel end() const
{
return {};
}
size_type_ size() const
{
return static_cast<size_type_>(n_);
}
};
namespace view
{
struct counted_fn
{
template<typename I,
CONCEPT_REQUIRES_(Iterator<I>())>
counted_view<I> operator()(I it, difference_type_t<I> n) const
{
return {std::move(it), n};
}
// TODO Once we support contiguous iterators, we can generalize this.
// (Note: it's not possible for RandomAccessIterators in general because
// of cyclic iterators.
template<typename T>
iterator_range<T*> operator()(T *t, std::ptrdiff_t n) const
{
return {t, t + n};
}
};
/// \relates counted_fn
/// \ingroup group-views
RANGES_INLINE_VARIABLE(counted_fn, counted)
}
/// @}
}
}
RANGES_SATISFY_BOOST_RANGE(::ranges::v3::counted_view)
#endif