[libcxx-commits] [libcxx] [libc++][ranges] LWG4096: `views::iota(views::iota(0))` should be rejected (PR #152855)

[Nikolas Klauser via libcxx-commits]

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@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++20
+
+// views::iota
+
+#include <ranges>
+
+#include "types.h"
+
+void test() {
+  // LWG4096
+  {
+    [[maybe_unused]] auto i1 = std::views::iota(0); // OK
+    [[maybe_unused]] auto i2 = std::views::iota(std::views::iota(0));
+    // expected-error@*:* {{no matching function for call to object of type 'const __iota::__fn'}}
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philnik777 wrote:

We shouldn't add verify tests if we can check through SFINAE.

https://github.com/llvm/llvm-project/pull/152855