template<class _Tp>
inline constexpr bool enable_borrowed_range<empty_view<_Tp>> = true;
+
+ namespace views {
+
+ template <class _Tp>
+ inline constexpr empty_view<_Tp> empty{};
+
+ } // namespace views
} // namespace ranges
#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
requires is_object_v<T>
class empty_view;
+ template<class T>
+ inline constexpr bool enable_borrowed_range<empty_view<T>> = true;
+
+ namespace views {
+ template<class T>
+ inline constexpr empty_view<T> empty{};
+ }
+
// [range.all], all view
namespace views {
inline constexpr unspecified all = unspecified;
--- /dev/null
+//===----------------------------------------------------------------------===//
+//
+// 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: libcpp-has-no-incomplete-ranges
+
+// template <class _Tp>
+// inline constexpr empty_view<_Tp> empty{};
+
+#include <ranges>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <class T>
+constexpr void testType() {
+ ASSERT_SAME_TYPE(decltype(std::views::empty<T>), const std::ranges::empty_view<T>);
+ ASSERT_SAME_TYPE(decltype((std::views::empty<T>)), const std::ranges::empty_view<T>&);
+
+ auto v = std::views::empty<T>;
+ assert(std::ranges::empty(v));
+}
+
+struct Empty {};
+struct BigType {
+ char buff[8];
+};
+
+constexpr bool test() {
+
+ testType<int>();
+ testType<const int>();
+ testType<int*>();
+ testType<Empty>();
+ testType<const Empty>();
+ testType<BigType>();
+
+ return true;
+}
+
+int main(int, char**) {
+ test();
+ static_assert(test());
+
+ return 0;
+}