Implement enable_view (#1208)

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

@@ -187,6 +187,7 @@ set(files
   __node_handle
   __nullptr
   __ranges/enable_borrowed_range.h
+  __ranges/enable_view.h
   __split_buffer
   __sso_allocator
   __std_stream
@@ -453,6 +454,7 @@ set(files
   ostream
   queue
   random
+  ranges
   ratio
   regex
   scoped_allocator

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

@@ -0,0 +1,80 @@
+// -*- 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_ENABLE_VIEW_H
+#define _LIBCUDACXX___RANGES_ENABLE_VIEW_H
+
+#ifndef __cuda_std__
+#include <__config>
+#endif // __cuda_std__
+
+#include "../__concepts/derived_from.h"
+#include "../__concepts/same_as.h"
+#include "../__type_traits/enable_if.h"
+#include "../__type_traits/is_class.h"
+#include "../__type_traits/remove_cv.h"
+#include "../__type_traits/void_t.h"
+
+#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
+_LIBCUDACXX_BEGIN_NAMESPACE_RANGES
+
+#if _LIBCUDACXX_STD_VER > 14
+
+struct view_base { };
+
+_LIBCUDACXX_BEGIN_NAMESPACE_RANGES_ABI
+
+#if _LIBCUDACXX_STD_VER > 17
+
+template<class _Derived>
+  requires is_class_v<_Derived> && same_as<_Derived, remove_cv_t<_Derived>>
+class view_interface;
+
+#else
+
+template<class _Derived, enable_if_t<is_class_v<_Derived> && same_as<_Derived, remove_cv_t<_Derived>>, int> = 0>
+class view_interface;
+
+#endif // _LIBCUDACXX_STD_VER < 17
+
+_LIBCUDACXX_END_NAMESPACE_RANGES_ABI
+
+_LIBCUDACXX_TEMPLATE(class _Op, class _Yp)
+  _LIBCUDACXX_REQUIRES(is_convertible_v<_Op*, view_interface<_Yp>*>)
+_LIBCUDACXX_INLINE_VISIBILITY
+void __is_derived_from_view_interface(const _Op*, const view_interface<_Yp>*);
+
+#if _LIBCUDACXX_STD_VER > 17
+
+template <class _Tp>
+_LIBCUDACXX_INLINE_VAR constexpr bool enable_view = derived_from<_Tp, view_base> ||
+  requires { _CUDA_VRANGES::__is_derived_from_view_interface((_Tp*)nullptr, (_Tp*)nullptr); };
+
+#else
+
+template <class _Tp, class = void>
+_LIBCUDACXX_INLINE_VAR constexpr bool enable_view = derived_from<_Tp, view_base>;
+
+template <class _Tp>
+_LIBCUDACXX_INLINE_VAR constexpr bool enable_view<_Tp,
+  void_t<decltype(_CUDA_VRANGES::__is_derived_from_view_interface((_Tp*)nullptr, (_Tp*)nullptr))>> = true;
+#endif // _LIBCUDACXX_STD_VER < 17
+
+#endif // _LIBCUDACXX_STD_VER > 14
+
+_LIBCUDACXX_END_NAMESPACE_RANGES
+
+#endif // _LIBCUDACXX___RANGES_ENABLE_VIEW_H

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

@@ -312,6 +312,7 @@ namespace std {
 
 #include "__assert" // all public C++ headers provide the assertion handler
 #include "__ranges/enable_borrowed_range.h"
+#include "__ranges/enable_view.h"
 
 // standard-mandated includes
 #include "version"

libcudacxx/include/cuda/std/detail/libcxx/include/span

@@ -144,6 +144,7 @@ template<class R>
 #include "__iterator/wrap_iter.h"
 #include "__memory/pointer_traits.h"
 #include "__ranges/enable_borrowed_range.h"
+#include "__ranges/enable_view.h"
 #include "__type_traits/enable_if.h"
 #include "__type_traits/integral_constant.h"
 #include "__type_traits/is_array.h"
@@ -581,6 +582,9 @@ _LIBCUDACXX_END_NAMESPACE_STD
 _LIBCUDACXX_BEGIN_NAMESPACE_RANGES
 template<class _Tp, size_t _Extent>
 _LIBCUDACXX_INLINE_VAR constexpr bool enable_borrowed_range<span<_Tp, _Extent>> = true;
+
+template <class _Tp, size_t _Extent>
+_LIBCUDACXX_INLINE_VAR constexpr bool enable_view<span<_Tp, _Extent>> = true;
 _LIBCUDACXX_END_NAMESPACE_RANGES
 #endif // _CCCL_STD_VER > 2014
 

libcudacxx/libcxx/test/std/containers/views/views.span/range_concept_conformance.compile.pass.cpp

@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: msvc-19.16
+
+// span
+
+#include <span>
+
+#include <concepts>
+#include <ranges>
+
+using range = std::span<int>;
+
+#ifdef _LIBCUDACXX_HAS_RANGES
+static_assert(std::same_as<std::ranges::iterator_t<range>, range::iterator>);
+static_assert(std::ranges::common_range<range>);
+static_assert(std::ranges::random_access_range<range>);
+static_assert(std::ranges::contiguous_range<range>);
+static_assert(std::ranges::view<range> && std::ranges::enable_view<range>);
+static_assert(std::ranges::sized_range<range>);
+static_assert(std::ranges::borrowed_range<range>);
+static_assert(std::ranges::viewable_range<range>);
+
+static_assert(std::same_as<std::ranges::iterator_t<range const>, range::iterator>);
+static_assert(std::ranges::common_range<range const>);
+static_assert(std::ranges::random_access_range<range const>);
+static_assert(std::ranges::contiguous_range<range const>);
+static_assert(!std::ranges::view<range const> && !std::ranges::enable_view<range const>);
+static_assert(std::ranges::sized_range<range const>);
+static_assert(std::ranges::borrowed_range<range const>);
+static_assert(std::ranges::viewable_range<range const>);
+#endif // _LIBCUDACXX_HAS_RANGES
+
+int main(int, char**)
+{
+    return 0;
+}

libcudacxx/test/libcudacxx/std/views/views.span/range_concept_conformance.compile.pass.cpp

@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// UNSUPPORTED: msvc-19.16
+
+// span
+
+#include <cuda/std/span>
+
+#include <cuda/std/concepts>
+#include <cuda/std/ranges>
+
+using range = cuda::std::span<int>;
+
+#ifdef _LIBCUDACXX_HAS_RANGES
+static_assert(cuda::std::same_as<cuda::std::ranges::iterator_t<range>, range::iterator>);
+static_assert(cuda::std::ranges::common_range<range>);
+static_assert(cuda::std::ranges::random_access_range<range>);
+static_assert(cuda::std::ranges::contiguous_range<range>);
+static_assert(cuda::std::ranges::view<range> && cuda::std::ranges::enable_view<range>);
+static_assert(cuda::std::ranges::sized_range<range>);
+static_assert(cuda::std::ranges::borrowed_range<range>);
+static_assert(cuda::std::ranges::viewable_range<range>);
+
+static_assert(cuda::std::same_as<cuda::std::ranges::iterator_t<range const>, range::iterator>);
+static_assert(cuda::std::ranges::common_range<range const>);
+static_assert(cuda::std::ranges::random_access_range<range const>);
+static_assert(cuda::std::ranges::contiguous_range<range const>);
+static_assert(!cuda::std::ranges::view<range const> && !cuda::std::ranges::enable_view<range const>);
+static_assert(cuda::std::ranges::sized_range<range const>);
+static_assert(cuda::std::ranges::borrowed_range<range const>);
+static_assert(cuda::std::ranges::viewable_range<range const>);
+#endif // _LIBCUDACXX_HAS_RANGES
+
+int main(int, char**)
+{
+    return 0;
+}