Implement ranges::{c}rend (#1301)

libcudacxx/include/cuda/std/detail/libcxx/include/CMakeLists.txt

@@ -190,6 +190,7 @@ set(files
   __ranges/enable_borrowed_range.h
   __ranges/enable_view.h
   __ranges/rbegin.h
+  __ranges/rend.h
   __split_buffer
   __sso_allocator
   __std_stream

libcudacxx/include/cuda/std/detail/libcxx/include/__ranges/rend.h

@@ -0,0 +1,191 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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
+// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
+//
+//===----------------------------------------------------------------------===//
+#ifndef _LIBCUDACXX___RANGES_REND_H
+#define _LIBCUDACXX___RANGES_REND_H
+
+#ifndef __cuda_std__
+#include <__config>
+#endif // __cuda_std__
+
+#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
+#  pragma GCC system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
+#  pragma clang system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
+#  pragma system_header
+#endif // no system header
+
+#include "../__concepts/class_or_enum.h"
+#include "../__concepts/same_as.h"
+#include "../__iterator/concepts.h"
+#include "../__iterator/readable_traits.h"
+#include "../__iterator/reverse_iterator.h"
+#include "../__ranges/access.h"
+#include "../__ranges/rbegin.h"
+#include "../__type_traits/is_reference.h"
+#include "../__type_traits/remove_cvref.h"
+#include "../__type_traits/remove_reference.h"
+#include "../__utility/auto_cast.h"
+
+_LIBCUDACXX_BEGIN_NAMESPACE_RANGES
+
+#if _CCCL_STD_VER >= 2017 && !defined(_LIBCUDACXX_COMPILER_MSVC_2017)
+
+// [range.access.rend]
+
+_LIBCUDACXX_BEGIN_NAMESPACE_CPO(__rend)
+  template<class _Tp>
+  void rend(_Tp&) = delete;
+  template<class _Tp>
+  void rend(const _Tp&) = delete;
+
+#if _CCCL_STD_VER >= 2020
+  template <class _Tp>
+  concept __member_rend =
+    __can_borrow<_Tp> &&
+    __workaround_52970<_Tp> &&
+    requires(_Tp&& __t) {
+      _CUDA_VRANGES::rbegin(__t);
+      { _LIBCUDACXX_AUTO_CAST(__t.rend()) } -> sentinel_for<decltype(_CUDA_VRANGES::rbegin(__t))>;
+    };
+
+
+  template <class _Tp>
+  concept __unqualified_rend =
+    !__member_rend<_Tp> &&
+    __can_borrow<_Tp> &&
+    __class_or_enum<remove_cvref_t<_Tp>> &&
+    requires(_Tp&& __t) {
+      _CUDA_VRANGES::rbegin(__t);
+      { _LIBCUDACXX_AUTO_CAST(rend(__t)) } -> sentinel_for<decltype(_CUDA_VRANGES::rbegin(__t))>;
+    };
+
+  template <class _Tp>
+  concept __can_reverse =
+    __can_borrow<_Tp> &&
+    !__member_rend<_Tp> &&
+    !__unqualified_rend<_Tp> &&
+    requires(_Tp&& __t) {
+      { _CUDA_VRANGES::begin(__t) } -> same_as<decltype(_CUDA_VRANGES::end(__t))>;
+      { _CUDA_VRANGES::begin(__t) } -> bidirectional_iterator;
+    };
+#else // ^^^ CXX20 ^^^ / vvv CXX17 vvv
+  template<class _Tp>
+  _LIBCUDACXX_CONCEPT_FRAGMENT(
+    __member_rend_,
+    requires(_Tp&& __t)(
+      requires(__can_borrow<_Tp>),
+      requires(__workaround_52970<_Tp>),
+      typename(decltype(_CUDA_VRANGES::rbegin(__t))),
+      requires(sentinel_for<decltype(_LIBCUDACXX_AUTO_CAST(__t.rend())), decltype(_CUDA_VRANGES::rbegin(__t))>)
+    ));
+
+  template<class _Tp>
+  _LIBCUDACXX_CONCEPT __member_rend = _LIBCUDACXX_FRAGMENT(__member_rend_, _Tp);
+
+  template<class _Tp>
+  _LIBCUDACXX_CONCEPT_FRAGMENT(
+    __unqualified_rend_,
+    requires(_Tp&& __t)(
+      requires(!__member_rend<_Tp>),
+      requires(__can_borrow<_Tp>),
+      requires(__class_or_enum<remove_cvref_t<_Tp>>),
+      typename(decltype(_CUDA_VRANGES::rbegin(__t))),
+      requires(sentinel_for<decltype(_LIBCUDACXX_AUTO_CAST(rend(__t))), decltype(_CUDA_VRANGES::rbegin(__t))>)
+    ));
+
+  template<class _Tp>
+  _LIBCUDACXX_CONCEPT __unqualified_rend = _LIBCUDACXX_FRAGMENT(__unqualified_rend_, _Tp);
+
+  template<class _Tp>
+  _LIBCUDACXX_CONCEPT_FRAGMENT(
+    __can_reverse_,
+    requires(_Tp&& __t)(
+      requires(!__member_rend<_Tp>),
+      requires(!__unqualified_rend<_Tp>),
+      requires(__can_borrow<_Tp>),
+      requires(same_as<decltype(_CUDA_VRANGES::begin(__t)), decltype(_CUDA_VRANGES::end(__t))>),
+      requires(bidirectional_iterator<decltype(_CUDA_VRANGES::begin(__t))>)
+    ));
+
+  template<class _Tp>
+  _LIBCUDACXX_CONCEPT __can_reverse = _LIBCUDACXX_FRAGMENT(__can_reverse_, _Tp);
+#endif // _CCCL_STD_VER <= 2017
+
+  class __fn {
+  public:
+    _LIBCUDACXX_TEMPLATE(class _Tp)
+      _LIBCUDACXX_REQUIRES(__member_rend<_Tp>)
+    _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(_LIBCUDACXX_AUTO_CAST(__t.rend())))
+    {
+      return _LIBCUDACXX_AUTO_CAST(__t.rend());
+    }
+
+    _LIBCUDACXX_TEMPLATE(class _Tp)
+      _LIBCUDACXX_REQUIRES(__unqualified_rend<_Tp>)
+    _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(_LIBCUDACXX_AUTO_CAST(rend(__t))))
+    {
+      return _LIBCUDACXX_AUTO_CAST(rend(__t));
+    }
+
+    _LIBCUDACXX_TEMPLATE(class _Tp)
+      _LIBCUDACXX_REQUIRES(__can_reverse<_Tp>)
+    _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(_CUDA_VRANGES::begin(__t)))
+    {
+      return _CUDA_VSTD::make_reverse_iterator(_CUDA_VRANGES::begin(__t));
+    }
+
+    _LIBCUDACXX_TEMPLATE(class _Tp)
+      _LIBCUDACXX_REQUIRES((!__member_rend<_Tp> && !__unqualified_rend<_Tp> && !__can_reverse<_Tp>))
+    void operator()(_Tp&&) const = delete;
+  };
+_LIBCUDACXX_END_NAMESPACE_CPO
+
+inline namespace __cpo {
+  _LIBCUDACXX_CPO_ACCESSIBILITY auto rend = __rend::__fn{};
+} // namespace __cpo
+
+// [range.access.crend]
+
+_LIBCUDACXX_BEGIN_NAMESPACE_CPO(__crend)
+  struct __fn {
+    _LIBCUDACXX_TEMPLATE(class _Tp)
+      _LIBCUDACXX_REQUIRES(is_lvalue_reference_v<_Tp&&>)
+    _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(_CUDA_VRANGES::rend(static_cast<const remove_reference_t<_Tp>&>(__t))))
+      -> decltype(      _CUDA_VRANGES::rend(static_cast<const remove_reference_t<_Tp>&>(__t)))
+      { return          _CUDA_VRANGES::rend(static_cast<const remove_reference_t<_Tp>&>(__t)); }
+
+    _LIBCUDACXX_TEMPLATE(class _Tp)
+      _LIBCUDACXX_REQUIRES(is_rvalue_reference_v<_Tp&&>)
+    _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY
+    constexpr auto operator()(_Tp&& __t) const
+      noexcept(noexcept(_CUDA_VRANGES::rend(static_cast<const _Tp&&>(__t))))
+      -> decltype(      _CUDA_VRANGES::rend(static_cast<const _Tp&&>(__t)))
+      { return          _CUDA_VRANGES::rend(static_cast<const _Tp&&>(__t)); }
+  };
+_LIBCUDACXX_END_NAMESPACE_CPO
+
+inline namespace __cpo {
+  _LIBCUDACXX_CPO_ACCESSIBILITY auto crend = __crend::__fn{};
+} // namespace __cpo
+
+#endif // _CCCL_STD_VER >= 2017 && !_LIBCUDACXX_COMPILER_MSVC_2017
+
+_LIBCUDACXX_END_NAMESPACE_RANGES
+
+#endif // _LIBCUDACXX___RANGES_REND_H

libcudacxx/include/cuda/std/detail/libcxx/include/ranges

@@ -315,6 +315,7 @@ namespace std {
 #include "__ranges/enable_borrowed_range.h"
 #include "__ranges/enable_view.h"
 #include "__ranges/rbegin.h"
+#include "__ranges/rend.h"
 
 // standard-mandated includes
 #include "version"