xref: /llvm-project/libcxx/include/__algorithm/ranges_contains_subrange.h (revision d10dc5a06fac4dcabf2264c64c8672c6f6ae36fb)

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ALGORITHM_RANGES_CONTAINS_SUBRANGE_H
#define _LIBCPP___ALGORITHM_RANGES_CONTAINS_SUBRANGE_H

#include <__algorithm/ranges_search.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/ranges_operations.h>
#include <__functional/reference_wrapper.h>
#include <__iterator/concepts.h>
#include <__iterator/indirectly_comparable.h>
#include <__iterator/projected.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/size.h>
#include <__ranges/subrange.h>
#include <__utility/move.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>

#if _LIBCPP_STD_VER >= 23

_LIBCPP_BEGIN_NAMESPACE_STD

namespace ranges {
struct __contains_subrange {
  template <forward_iterator _Iter1,
            sentinel_for<_Iter1> _Sent1,
            forward_iterator _Iter2,
            sentinel_for<_Iter2> _Sent2,
            class _Pred  = ranges::equal_to,
            class _Proj1 = identity,
            class _Proj2 = identity>
    requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool static operator()(
      _Iter1 __first1,
      _Sent1 __last1,
      _Iter2 __first2,
      _Sent2 __last2,
      _Pred __pred   = {},
      _Proj1 __proj1 = {},
      _Proj2 __proj2 = {}) {
    if (__first2 == __last2)
      return true;

    auto __ret = ranges::search(
        std::move(__first1), __last1, std::move(__first2), __last2, __pred, std::ref(__proj1), std::ref(__proj2));
    return __ret.empty() == false;
  }

  template <forward_range _Range1,
            forward_range _Range2,
            class _Pred  = ranges::equal_to,
            class _Proj1 = identity,
            class _Proj2 = identity>
    requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool static
  operator()(_Range1&& __range1, _Range2&& __range2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) {
    if constexpr (sized_range<_Range2>) {
      if (ranges::size(__range2) == 0)
        return true;
    } else {
      if (ranges::begin(__range2) == ranges::end(__range2))
        return true;
    }

    auto __ret = ranges::search(__range1, __range2, __pred, std::ref(__proj1), std::ref(__proj2));
    return __ret.empty() == false;
  }
};

inline namespace __cpo {
inline constexpr auto contains_subrange = __contains_subrange{};
} // namespace __cpo
} // namespace ranges

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP_STD_VER >= 23

_LIBCPP_POP_MACROS

#endif // _LIBCPP___ALGORITHM_RANGES_CONTAINS_SUBRANGE_H