Implement ranges::size and ranges::ssize (#1330)

Fixes #1329

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

@@ -192,6 +192,7 @@ set(files
   __ranges/enable_view.h
   __ranges/rbegin.h
   __ranges/rend.h
+  __ranges/size.h
   __split_buffer
   __sso_allocator
   __std_stream

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

@@ -0,0 +1,219 @@
+// -*- 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) 2024 NVIDIA CORPORATION & AFFILIATES.
+//
+//===----------------------------------------------------------------------===//
+#ifndef _LIBCUDACXX___RANGES_SIZE_H
+#define _LIBCUDACXX___RANGES_SIZE_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/arithmetic.h"
+#include "../__concepts/class_or_enum.h"
+#include "../__iterator/concepts.h"
+#include "../__iterator/iterator_traits.h"
+#include "../__memory/pointer_traits.h"
+#include "../__ranges/access.h"
+#include "../__type_traits/is_unbounded_array.h"
+#include "../__type_traits/make_unsigned.h"
+#include "../__type_traits/make_signed.h"
+#include "../__type_traits/remove_cvref.h"
+#include "../__utility/auto_cast.h"
+#include "../__utility/declval.h"
+#include "../cstddef"
+#include "../cstdlib"
+
+_LIBCUDACXX_BEGIN_NAMESPACE_RANGES
+
+#if _CCCL_STD_VER >= 2017 && !defined(_LIBCUDACXX_COMPILER_MSVC_2017)
+
+template <class>
+_LIBCUDACXX_INLINE_VAR constexpr bool disable_sized_range = false;
+
+// [range.prim.size]
+
+_LIBCUDACXX_BEGIN_NAMESPACE_CPO(__size)
+template <class _Tp>
+void size(_Tp&) = delete;
+template <class _Tp>
+void size(const _Tp&) = delete;
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT __size_enabled = !disable_sized_range<remove_cvref_t<_Tp>>;
+
+#  if _CCCL_STD_VER >= 2020
+template <class _Tp>
+concept __member_size = __size_enabled<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+  {
+    _LIBCUDACXX_AUTO_CAST(__t.size())
+  } -> __integer_like;
+};
+
+template <class _Tp>
+concept __unqualified_size =
+  __size_enabled<_Tp> && !__member_size<_Tp> && __class_or_enum<remove_cvref_t<_Tp>> && requires(_Tp&& __t) {
+    {
+      _LIBCUDACXX_AUTO_CAST(size(__t))
+    } -> __integer_like;
+  };
+
+template <class _Tp>
+concept __difference =
+  !__member_size<_Tp> && !__unqualified_size<_Tp> && __class_or_enum<remove_cvref_t<_Tp>> && requires(_Tp&& __t) {
+    {
+      _CUDA_VRANGES::begin(__t)
+    } -> forward_iterator;
+    {
+      _CUDA_VRANGES::end(__t)
+    } -> sized_sentinel_for<decltype(_CUDA_VRANGES::begin(_CUDA_VSTD::declval<_Tp>()))>;
+  };
+#  else // ^^^ CXX20 ^^^ / vvv CXX17 vvv
+template <class _Tp>
+_LIBCUDACXX_CONCEPT_FRAGMENT(
+  __member_size_,
+  requires(_Tp&& __t)(requires(__size_enabled<_Tp>),
+                      requires(__workaround_52970<_Tp>),
+                      requires(__integer_like<decltype(_LIBCUDACXX_AUTO_CAST(__t.size()))>)));
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT __member_size = _LIBCUDACXX_FRAGMENT(__member_size_, _Tp);
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT_FRAGMENT(
+  __unqualified_size_,
+  requires(_Tp&& __t)(requires(__size_enabled<_Tp>),
+                      requires(!__member_size<_Tp>),
+                      requires(__class_or_enum<remove_cvref_t<_Tp>>),
+                      requires(__integer_like<decltype(_LIBCUDACXX_AUTO_CAST(size(__t)))>)));
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT __unqualified_size = _LIBCUDACXX_FRAGMENT(__unqualified_size_, _Tp);
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT_FRAGMENT(
+  __difference_,
+  requires(_Tp&& __t)(requires(!__member_size<_Tp>),
+                      requires(!__unqualified_size<_Tp>),
+                      requires(__class_or_enum<remove_cvref_t<_Tp>>),
+                      requires(forward_iterator<decltype(_CUDA_VRANGES::begin(__t))>),
+                      requires(sized_sentinel_for<decltype(_CUDA_VRANGES::end(__t)),
+                                                  decltype(_CUDA_VRANGES::begin(_CUDA_VSTD::declval<_Tp>()))>)));
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT __difference = _LIBCUDACXX_FRAGMENT(__difference_, _Tp);
+#  endif // _CCCL_STD_VER <= 2017
+
+struct __fn
+{
+  // `[range.prim.size]`: the array case (for rvalues).
+  template <class _Tp, size_t _Sz>
+  _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY constexpr size_t
+  operator()(_Tp (&&)[_Sz]) const noexcept
+  {
+    return _Sz;
+  }
+
+  // `[range.prim.size]`: the array case (for lvalues).
+  template <class _Tp, size_t _Sz>
+  _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY constexpr size_t
+  operator()(_Tp (&)[_Sz]) const noexcept
+  {
+    return _Sz;
+  }
+
+  // `[range.prim.size]`: `auto(t.size())` is a valid expression.
+  _LIBCUDACXX_TEMPLATE(class _Tp)
+  _LIBCUDACXX_REQUIRES(__member_size<_Tp>)
+  _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY constexpr auto
+  operator()(_Tp&& __t) const noexcept(noexcept(_LIBCUDACXX_AUTO_CAST(__t.size())))
+  {
+    return _LIBCUDACXX_AUTO_CAST(__t.size());
+  }
+
+  // `[range.prim.size]`: `auto(size(t))` is a valid expression.
+  _LIBCUDACXX_TEMPLATE(class _Tp)
+  _LIBCUDACXX_REQUIRES(__unqualified_size<_Tp>)
+  _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY constexpr auto
+  operator()(_Tp&& __t) const noexcept(noexcept(_LIBCUDACXX_AUTO_CAST(size(__t))))
+  {
+    return _LIBCUDACXX_AUTO_CAST(size(__t));
+  }
+
+  // [range.prim.size]: the `to-unsigned-like` case.
+  _LIBCUDACXX_TEMPLATE(class _Tp)
+  _LIBCUDACXX_REQUIRES(__difference<_Tp>)
+  _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY constexpr auto
+  operator()(_Tp&& __t) const
+    noexcept(noexcept(_CUDA_VSTD::__to_unsigned_like(_CUDA_VRANGES::end(__t) - _CUDA_VRANGES::begin(__t))))
+      -> decltype(_CUDA_VSTD::__to_unsigned_like(_CUDA_VRANGES::end(__t) - _CUDA_VRANGES::begin(__t)))
+  {
+    return _CUDA_VSTD::__to_unsigned_like(_CUDA_VRANGES::end(__t) - _CUDA_VRANGES::begin(__t));
+  }
+};
+_LIBCUDACXX_END_NAMESPACE_CPO
+
+inline namespace __cpo
+{
+_LIBCUDACXX_CPO_ACCESSIBILITY auto size = __size::__fn{};
+} // namespace __cpo
+
+// [range.prim.ssize]
+
+_LIBCUDACXX_BEGIN_NAMESPACE_CPO(__ssize)
+#  if _CCCL_STD_VER >= 2020
+template <class _Tp>
+concept __can_ssize = requires(_Tp&& __t) { _CUDA_VRANGES::size(__t); };
+#  else // ^^^ CXX20 ^^^ / vvv CXX17 vvv
+template <class _Tp>
+_LIBCUDACXX_CONCEPT_FRAGMENT(
+  __can_ssize_, requires(_Tp&& __t)(requires(!is_unbounded_array_v<_Tp>), ((void) _CUDA_VRANGES::size(__t))));
+
+template <class _Tp>
+_LIBCUDACXX_CONCEPT __can_ssize = _LIBCUDACXX_FRAGMENT(__can_ssize_, _Tp);
+#  endif // _CCCL_STD_VER <= 2017
+
+struct __fn
+{
+  _LIBCUDACXX_TEMPLATE(class _Tp)
+  _LIBCUDACXX_REQUIRES(__can_ssize<_Tp>)
+  _LIBCUDACXX_NODISCARD_ATTRIBUTE _LIBCUDACXX_HIDE_FROM_ABI _LIBCUDACXX_INLINE_VISIBILITY constexpr auto
+  operator()(_Tp&& __t) const noexcept(noexcept(_CUDA_VRANGES::size(__t)))
+  {
+    using _Signed = make_signed_t<decltype(_CUDA_VRANGES::size(__t))>;
+    if constexpr (sizeof(ptrdiff_t) > sizeof(_Signed))
+    {
+      return static_cast<ptrdiff_t>(_CUDA_VRANGES::size(__t));
+    }
+    else
+    {
+      return static_cast<_Signed>(_CUDA_VRANGES::size(__t));
+    }
+    _LIBCUDACXX_UNREACHABLE();
+  }
+};
+_LIBCUDACXX_END_NAMESPACE_CPO
+
+inline namespace __cpo
+{
+_LIBCUDACXX_CPO_ACCESSIBILITY auto ssize = __ssize::__fn{};
+} // namespace __cpo
+
+#endif // _CCCL_STD_VER >= 2017 && !_LIBCUDACXX_COMPILER_MSVC_2017
+
+_LIBCUDACXX_END_NAMESPACE_RANGES
+
+#endif // _LIBCUDACXX___RANGES_SIZE_H

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

@@ -317,6 +317,7 @@ namespace std {
 #include "__ranges/enable_view.h"
 #include "__ranges/rbegin.h"
 #include "__ranges/rend.h"
+#include "__ranges/size.h"
 
 // standard-mandated includes
 #include "version"