libcxx/include/__algorithm/ranges_rotate.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___ALGORITHM_RANGES_ROTATE_H
  10 #define _LIBCPP___ALGORITHM_RANGES_ROTATE_H
  11
  12 #include <__algorithm/iterator_operations.h>
  13 #include <__algorithm/ranges_iterator_concept.h>
  14 #include <__algorithm/rotate.h>
  15 #include <__config>
  16 #include <__iterator/concepts.h>
  17 #include <__iterator/iterator_traits.h>
  18 #include <__iterator/permutable.h>
  19 #include <__ranges/access.h>
  20 #include <__ranges/concepts.h>
  21 #include <__ranges/subrange.h>
  22 #include <__utility/move.h>
  23
  24 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  25 #  pragma GCC system_header
  26 #endif
  27
  28 #if _LIBCPP_STD_VER >= 20
  29
  30 _LIBCPP_BEGIN_NAMESPACE_STD
  31
  32 namespace ranges {
  33 namespace __rotate {
  34
  35 struct __fn {
  36   template <class _Iter, class _Sent>
  37   _LIBCPP_HIDE_FROM_ABI constexpr static subrange<_Iter> __rotate_fn_impl(_Iter __first, _Iter __middle, _Sent __last) {
  38     auto __ret = std::__rotate<_RangeAlgPolicy>(std::move(__first), std::move(__middle), std::move(__last));
  39     return {std::move(__ret.first), std::move(__ret.second)};
  40   }
  41
  42   template <permutable _Iter, sentinel_for<_Iter> _Sent>
  43   _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter> operator()(_Iter __first, _Iter __middle, _Sent __last) const {
  44     return __rotate_fn_impl(std::move(__first), std::move(__middle), std::move(__last));
  45   }
  46
  47   template <forward_range _Range>
  48     requires permutable<iterator_t<_Range>>
  49   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range>
  50   operator()(_Range&& __range, iterator_t<_Range> __middle) const {
  51     return __rotate_fn_impl(ranges::begin(__range), std::move(__middle), ranges::end(__range));
  52   }
  53 };
  54
  55 } // namespace __rotate
  56
  57 inline namespace __cpo {
  58 inline constexpr auto rotate = __rotate::__fn{};
  59 } // namespace __cpo
  60 } // namespace ranges
  61
  62 _LIBCPP_END_NAMESPACE_STD
  63
  64 #endif // _LIBCPP_STD_VER >= 20
  65
  66 #endif // _LIBCPP___ALGORITHM_RANGES_ROTATE_H