libcxx/include/__cxx03/__algorithm/ranges_copy_if.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_COPY_IF_H
  10 #define _LIBCPP___ALGORITHM_RANGES_COPY_IF_H
  11
  12 #include <__cxx03/__algorithm/in_out_result.h>
  13 #include <__cxx03/__config>
  14 #include <__cxx03/__functional/identity.h>
  15 #include <__cxx03/__functional/invoke.h>
  16 #include <__cxx03/__iterator/concepts.h>
  17 #include <__cxx03/__iterator/projected.h>
  18 #include <__cxx03/__ranges/access.h>
  19 #include <__cxx03/__ranges/concepts.h>
  20 #include <__cxx03/__ranges/dangling.h>
  21 #include <__cxx03/__utility/move.h>
  22
  23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  24 #  pragma GCC system_header
  25 #endif
  26
  27 _LIBCPP_PUSH_MACROS
  28 #include <__cxx03/__undef_macros>
  29
  30 #if _LIBCPP_STD_VER >= 20
  31
  32 _LIBCPP_BEGIN_NAMESPACE_STD
  33
  34 namespace ranges {
  35
  36 template <class _Ip, class _Op>
  37 using copy_if_result = in_out_result<_Ip, _Op>;
  38
  39 namespace __copy_if {
  40 struct __fn {
  41   template <class _InIter, class _Sent, class _OutIter, class _Proj, class _Pred>
  42   _LIBCPP_HIDE_FROM_ABI static constexpr copy_if_result<_InIter, _OutIter>
  43   __copy_if_impl(_InIter __first, _Sent __last, _OutIter __result, _Pred& __pred, _Proj& __proj) {
  44     for (; __first != __last; ++__first) {
  45       if (std::invoke(__pred, std::invoke(__proj, *__first))) {
  46         *__result = *__first;
  47         ++__result;
  48       }
  49     }
  50     return {std::move(__first), std::move(__result)};
  51   }
  52
  53   template <input_iterator _Iter,
  54             sentinel_for<_Iter> _Sent,
  55             weakly_incrementable _OutIter,
  56             class _Proj = identity,
  57             indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
  58     requires indirectly_copyable<_Iter, _OutIter>
  59   _LIBCPP_HIDE_FROM_ABI constexpr copy_if_result<_Iter, _OutIter>
  60   operator()(_Iter __first, _Sent __last, _OutIter __result, _Pred __pred, _Proj __proj = {}) const {
  61     return __copy_if_impl(std::move(__first), std::move(__last), std::move(__result), __pred, __proj);
  62   }
  63
  64   template <input_range _Range,
  65             weakly_incrementable _OutIter,
  66             class _Proj = identity,
  67             indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
  68     requires indirectly_copyable<iterator_t<_Range>, _OutIter>
  69   _LIBCPP_HIDE_FROM_ABI constexpr copy_if_result<borrowed_iterator_t<_Range>, _OutIter>
  70   operator()(_Range&& __r, _OutIter __result, _Pred __pred, _Proj __proj = {}) const {
  71     return __copy_if_impl(ranges::begin(__r), ranges::end(__r), std::move(__result), __pred, __proj);
  72   }
  73 };
  74 } // namespace __copy_if
  75
  76 inline namespace __cpo {
  77 inline constexpr auto copy_if = __copy_if::__fn{};
  78 } // namespace __cpo
  79 } // namespace ranges
  80
  81 _LIBCPP_END_NAMESPACE_STD
  82
  83 #endif // _LIBCPP_STD_VER >= 20
  84
  85 _LIBCPP_POP_MACROS
  86
  87 #endif // _LIBCPP___ALGORITHM_RANGES_COPY_IF_H