109 lines
4.1 KiB
C++
109 lines
4.1 KiB
C++
/// \file
|
|
// Range v3 library
|
|
//
|
|
// Copyright Eric Niebler 2014
|
|
// Copyright Casey Carter 2016
|
|
//
|
|
// 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
|
|
//
|
|
//===-------------------------- algorithm ---------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is dual licensed under the MIT and the University of Illinois Open
|
|
// Source Licenses. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
#ifndef RANGES_V3_ALGORITHM_PARTITION_POINT_HPP
|
|
#define RANGES_V3_ALGORITHM_PARTITION_POINT_HPP
|
|
|
|
#include <meta/meta.hpp>
|
|
#include <range/v3/range_fwd.hpp>
|
|
#include <range/v3/begin_end.hpp>
|
|
#include <range/v3/distance.hpp>
|
|
#include <range/v3/range_concepts.hpp>
|
|
#include <range/v3/range_traits.hpp>
|
|
#include <range/v3/algorithm/aux_/partition_point_n.hpp>
|
|
#include <range/v3/utility/iterator.hpp>
|
|
#include <range/v3/utility/iterator_concepts.hpp>
|
|
#include <range/v3/utility/iterator_traits.hpp>
|
|
#include <range/v3/utility/functional.hpp>
|
|
#include <range/v3/utility/static_const.hpp>
|
|
|
|
namespace ranges
|
|
{
|
|
inline namespace v3
|
|
{
|
|
/// \addtogroup group-algorithms
|
|
/// @{
|
|
|
|
struct partition_point_fn
|
|
{
|
|
template<typename I, typename S, typename C, typename P = ident,
|
|
CONCEPT_REQUIRES_(PartitionPointable<I, C, P>() &&
|
|
Sentinel<S, I>() && !SizedSentinel<S, I>())>
|
|
I operator()(I begin, S end, C pred, P proj = P{}) const
|
|
{
|
|
// Probe exponentially for either end-of-range or an iterator
|
|
// that is past the partition point (i.e., does not satisfy pred).
|
|
auto len = difference_type_t<I>{1};
|
|
while(true)
|
|
{
|
|
auto mid = begin;
|
|
auto d = advance(mid, len, end);
|
|
if(mid == end || !invoke(pred, invoke(proj, *mid)))
|
|
{
|
|
len -= d;
|
|
return aux::partition_point_n(
|
|
std::move(begin), len, std::ref(pred), std::ref(proj));
|
|
}
|
|
begin = std::move(mid);
|
|
len *= 2;
|
|
}
|
|
}
|
|
|
|
template<typename I, typename S, typename C, typename P = ident,
|
|
CONCEPT_REQUIRES_(PartitionPointable<I, C, P>() &&
|
|
SizedSentinel<S, I>())>
|
|
I operator()(I begin, S end, C pred, P proj = P{}) const
|
|
{
|
|
auto len = distance(begin, std::move(end));
|
|
return aux::partition_point_n(
|
|
std::move(begin), len, std::move(pred), std::move(proj));
|
|
}
|
|
|
|
template<typename Rng, typename C, typename P = ident,
|
|
typename I = iterator_t<Rng>,
|
|
CONCEPT_REQUIRES_(Range<Rng>() && !SizedRange<Rng>() &&
|
|
PartitionPointable<I, C, P>())>
|
|
safe_iterator_t<Rng> operator()(Rng && rng, C pred, P proj = P{}) const
|
|
{
|
|
return (*this)(
|
|
begin(rng), end(rng), std::move(pred), std::move(proj));
|
|
}
|
|
|
|
template<typename Rng, typename C, typename P = ident,
|
|
typename I = iterator_t<Rng>,
|
|
CONCEPT_REQUIRES_(SizedRange<Rng>() && PartitionPointable<I, C, P>())>
|
|
safe_iterator_t<Rng> operator()(Rng && rng, C pred, P proj = P{}) const
|
|
{
|
|
auto len = distance(rng);
|
|
return aux::partition_point_n(
|
|
begin(rng), len, std::move(pred), std::move(proj));
|
|
}
|
|
};
|
|
|
|
/// \sa `partition_point_fn`
|
|
/// \ingroup group-algorithms
|
|
RANGES_INLINE_VARIABLE(with_braced_init_args<partition_point_fn>, partition_point)
|
|
/// @}
|
|
} // namespace v3
|
|
} // namespace ranges
|
|
|
|
#endif // include guard
|