commit 2fbc4d2e12c87f62c717f69f09e847873325f115
author zoecarver <z.zoelec2@gmail.com> Fri Apr 23 15:22:18 2021 -0700
committer Copybara-Service <copybara-worker@google.com> Fri May 21 11:15:45 2021 -0700
tree 53baaaa5c499154a2840690f89ac9a1d0d187b83
parent 382d342ea664212b3d0b4165836f18b8993ea543

[libcxx][ranges] Add ranges::data CPO.

This is the second to last one! Based on D101396. Depends on D100255. Refs D101079 and D101193.

Differential Revision: https://reviews.llvm.org/D101476

NOKEYCHECK=True
GitOrigin-RevId: 9db55b314b5b9e387ed36fe61b829efcc98b7c7b

include/CMakeLists.txt

diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index d08d156..4a58a2c 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -37,6 +37,7 @@
   __nullptr
   __ranges/access.h
   __ranges/concepts.h
+  __ranges/data.h
   __ranges/empty.h
   __ranges/enable_borrowed_range.h
   __ranges/view.h

include/__ranges/data.h

diff --git a/include/__ranges/data.h b/include/__ranges/data.h
new file mode 100644
index 0000000..8054667
--- /dev/null
+++ b/include/__ranges/data.h
@@ -0,0 +1,83 @@
+// -*- C++ -*-
+//===------------------------ __ranges/data.h ------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+#ifndef _LIBCPP___RANGES_DATA_H
+#define _LIBCPP___RANGES_DATA_H
+
+#include <__config>
+
+#include <concepts>
+#include <__iterator/concepts.h>
+#include <__iterator/iterator_traits.h>
+#include <__ranges/access.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if !defined(_LIBCPP_HAS_NO_RANGES)
+
+// clang-format off
+namespace ranges {
+// [range.prim.data]
+namespace __data {
+  template <class _Tp>
+  concept __ptr_to_object = is_pointer_v<_Tp> && is_object_v<remove_pointer_t<_Tp>>;
+
+  template <class _Tp>
+  concept __member_data =
+    requires(_Tp&& __t) {
+      { _VSTD::forward<_Tp>(__t) } -> __can_borrow;
+      { __t.data() } -> __ptr_to_object;
+    };
+
+  template <class _Tp>
+  concept __ranges_begin_invocable =
+    !__member_data<_Tp> &&
+    requires(_Tp&& __t) {
+      { _VSTD::forward<_Tp>(__t) } -> __can_borrow;
+      { ranges::begin(_VSTD::forward<_Tp>(__t)) } -> contiguous_iterator;
+    };
+
+  struct __fn {
+    template <__member_data _Tp>
+      requires __can_borrow<_Tp>
+    constexpr __ptr_to_object auto operator()(_Tp&& __t) const
+        noexcept(noexcept(__t.data())) {
+      return __t.data();
+    }
+
+    template<__ranges_begin_invocable _Tp>
+      requires __can_borrow<_Tp>
+    constexpr __ptr_to_object auto operator()(_Tp&& __t) const
+        noexcept(noexcept(_VSTD::to_address(ranges::begin(_VSTD::forward<_Tp>(__t))))) {
+      return _VSTD::to_address(ranges::begin(_VSTD::forward<_Tp>(__t)));
+    }
+  };
+} // end namespace __data
+
+inline namespace __cpo {
+  inline constexpr const auto data = __data::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+// clang-format off
+
+#endif // !defined(_LIBCPP_HAS_NO_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___RANGES_DATA_H

include/ranges

diff --git a/include/ranges b/include/ranges
index da443d7..fb14010 100644
--- a/include/ranges
+++ b/include/ranges
@@ -85,6 +85,7 @@
 #include <__config>
 #include <__ranges/access.h>
 #include <__ranges/concepts.h>
+#include <__ranges/data.h>
 #include <__ranges/empty.h>
 #include <__ranges/enable_borrowed_range.h>
 #include <__ranges/view.h>