[libcxx-commits] [libcxx] [libc++] Implement `views::join_with` (PR #65536)

[via libcxx-commits]

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@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+// 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, c++20
+
+// <ranges>
+
+// constexpr sentinel(sentinel<!Const> s)
+//   requires Const && convertible_to<sentinel_t<V>, sentinel_t<Base>>;
+
+#include <ranges>
+
+#include <type_traits>
+#include <vector>
+
+#include "../types.h"
+#include "test_iterators.h"
+
+constexpr bool test() {
+  { // Regular conversion from `!Const` to `Const` sentinel
+    using Inner            = BasicVectorView<int, ViewProperties{.common = false}, forward_iterator>;
+    std::vector<Inner> vec = {Inner{11, 12}, Inner{13, 14}};
+
+    std::ranges::join_with_view jwv(vec, 0);
+    using JWV = decltype(jwv);
+    static_assert(!std::ranges::common_range<JWV>);
+    using CSent = std::ranges::sentinel_t<const JWV>;
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huixie90 wrote:

can we `static_assert(!std::same_as<Sent, CSent>)` to make sure we are testing what we are supposed to test

https://github.com/llvm/llvm-project/pull/65536