libcxx/include/__algorithm/ranges_find.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_FIND_H
  10 #define _LIBCPP___ALGORITHM_RANGES_FIND_H
  11
  12 #include <__algorithm/find.h>
  13 #include <__algorithm/ranges_find_if.h>
  14 #include <__algorithm/unwrap_range.h>
  15 #include <__config>
  16 #include <__functional/identity.h>
  17 #include <__functional/invoke.h>
  18 #include <__functional/ranges_operations.h>
  19 #include <__iterator/concepts.h>
  20 #include <__iterator/projected.h>
  21 #include <__ranges/access.h>
  22 #include <__ranges/concepts.h>
  23 #include <__ranges/dangling.h>
  24 #include <__utility/forward.h>
  25 #include <__utility/move.h>
  26
  27 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  28 #  pragma GCC system_header
  29 #endif
  30
  31 #if _LIBCPP_STD_VER >= 20
  32
  33 _LIBCPP_BEGIN_NAMESPACE_STD
  34
  35 namespace ranges {
  36 namespace __find {
  37 struct __fn {
  38   template <class _Iter, class _Sent, class _Tp, class _Proj>
  39   _LIBCPP_HIDE_FROM_ABI static constexpr _Iter
  40   __find_unwrap(_Iter __first, _Sent __last, const _Tp& __value, _Proj& __proj) {
  41     if constexpr (forward_iterator<_Iter>) {
  42       auto [__first_un, __last_un] = std::__unwrap_range(__first, std::move(__last));
  43       return std::__rewrap_range<_Sent>(
  44           std::move(__first), std::__find_impl(std::move(__first_un), std::move(__last_un), __value, __proj));
  45     } else {
  46       return std::__find_impl(std::move(__first), std::move(__last), __value, __proj);
  47     }
  48   }
  49
  50   template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Tp, class _Proj = identity>
  51     requires indirect_binary_predicate<ranges::equal_to, projected<_Ip, _Proj>, const _Tp*>
  52   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr _Ip
  53   operator()(_Ip __first, _Sp __last, const _Tp& __value, _Proj __proj = {}) const {
  54     return __find_unwrap(std::move(__first), std::move(__last), __value, __proj);
  55   }
  56
  57   template <input_range _Rp, class _Tp, class _Proj = identity>
  58     requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Rp>, _Proj>, const _Tp*>
  59   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp>
  60   operator()(_Rp&& __r, const _Tp& __value, _Proj __proj = {}) const {
  61     return __find_unwrap(ranges::begin(__r), ranges::end(__r), __value, __proj);
  62   }
  63 };
  64 } // namespace __find
  65
  66 inline namespace __cpo {
  67 inline constexpr auto find = __find::__fn{};
  68 } // namespace __cpo
  69 } // namespace ranges
  70
  71 _LIBCPP_END_NAMESPACE_STD
  72
  73 #endif // _LIBCPP_STD_VER >= 20
  74
  75 #endif // _LIBCPP___ALGORITHM_RANGES_FIND_H