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/// \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_ALGORITHM_UNIQUE_COPY_HPP
#define RANGES_V3_ALGORITHM_UNIQUE_COPY_HPP
#include <meta/meta.hpp>
#include <range/v3/range_fwd.hpp>
#include <range/v3/algorithm/result_types.hpp>
#include <range/v3/functional/comparisons.hpp>
#include <range/v3/functional/identity.hpp>
#include <range/v3/functional/invoke.hpp>
#include <range/v3/iterator/concepts.hpp>
#include <range/v3/iterator/traits.hpp>
#include <range/v3/range/access.hpp>
#include <range/v3/range/concepts.hpp>
#include <range/v3/range/dangling.hpp>
#include <range/v3/range/traits.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/detail/prologue.hpp>
namespace ranges
{
/// \addtogroup group-algorithms
/// @{
template<typename I, typename O>
using unique_copy_result = detail::in_out_result<I, O>;
/// \cond
namespace detail
{
template<typename I, typename S, typename O, typename C, typename P>
constexpr unique_copy_result<I, O> unique_copy_impl(I first,
S last,
O out,
C pred,
P proj,
std::input_iterator_tag,
std::false_type)
{
if(first != last)
{
// Must save a copy into a local because we will need this value
// even after we advance the input iterator.
iter_value_t<I> value =
*first; // This is guaranteed by indirectly_copyable
*out = value;
++out;
while(++first != last)
{
auto && x = *first;
if(!invoke(pred, invoke(proj, value), invoke(proj, x)))
{
value = (decltype(x) &&)x;
*out = value;
++out;
}
}
}
return {first, out};
}
template<typename I, typename S, typename O, typename C, typename P>
constexpr unique_copy_result<I, O> unique_copy_impl(I first,
S last,
O out,
C pred,
P proj,
std::forward_iterator_tag,
std::false_type)
{
if(first != last)
{
I tmp = first;
*out = *tmp;
++out;
while(++first != last)
{
auto && x = *first;
if(!invoke(pred, invoke(proj, *tmp), invoke(proj, x)))
{
*out = (decltype(x) &&)x;
++out;
tmp = first;
}
}
}
return {first, out};
}
template<typename I, typename S, typename O, typename C, typename P>
constexpr unique_copy_result<I, O> unique_copy_impl(I first,
S last,
O out,
C pred,
P proj,
std::input_iterator_tag, std::true_type)
{
if(first != last)
{
*out = *first;
while(++first != last)
{
auto && x = *first;
if(!invoke(pred, invoke(proj, *out), invoke(proj, x)))
*++out = (decltype(x) &&)x;
}
++out;
}
return {first, out};
}
} // namespace detail
/// \endcond
RANGES_FUNC_BEGIN(unique_copy)
/// \brief template function unique_copy
///
/// range-based version of the `unique_copy` std algorithm
///
/// \pre `Rng` is a model of the `input_range` concept
/// \pre `O` is a model of the `weakly_incrementable` concept
/// \pre `C` is a model of the `relation` concept
template(typename I,
typename S,
typename O,
typename C = equal_to,
typename P = identity)(
requires input_iterator<I> AND sentinel_for<S, I> AND
indirect_relation<C, projected<I, P>> AND weakly_incrementable<O> AND
indirectly_copyable<I, O> AND
(forward_iterator<I> || forward_iterator<O> ||
indirectly_copyable_storable<I, O>)) //
constexpr unique_copy_result<I, O> RANGES_FUNC(unique_copy)(
I first, S last, O out, C pred = C{}, P proj = P{}) //
{
return detail::unique_copy_impl(std::move(first),
std::move(last),
std::move(out),
std::move(pred),
std::move(proj),
iterator_tag_of<I>(),
meta::bool_<forward_iterator<O>>{});
}
/// \overload
template(typename Rng, typename O, typename C = equal_to, typename P = identity)(
requires input_range<Rng> AND
indirect_relation<C, projected<iterator_t<Rng>, P>> AND
weakly_incrementable<O> AND indirectly_copyable<iterator_t<Rng>, O> AND
(forward_iterator<iterator_t<Rng>> || forward_iterator<O> ||
indirectly_copyable_storable<iterator_t<Rng>, O>)) //
constexpr unique_copy_result<borrowed_iterator_t<Rng>, O> //
RANGES_FUNC(unique_copy)(Rng && rng, O out, C pred = C{}, P proj = P{}) //
{
return detail::unique_copy_impl(begin(rng),
end(rng),
std::move(out),
std::move(pred),
std::move(proj),
iterator_tag_of<iterator_t<Rng>>(),
meta::bool_<forward_iterator<O>>{});
}
RANGES_FUNC_END(unique_copy)
namespace cpp20
{
using ranges::unique_copy;
using ranges::unique_copy_result;
} // namespace cpp20
/// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#endif
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