[clang] [libcxx] [clang & libcxx] constexpr pointer tagging (DO NOT MERGE) (PR #111861)

[Louis Dionne via cfe-commits]

Hana =?utf-8?q?Dusíková?= <hanicka at hanicka.net>,
Hana =?utf-8?q?Dusíková?= <hanicka at hanicka.net>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/111861 at github.com>


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@@ -0,0 +1,517 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TAGGED_PTR_H
+#define _LIBCPP___TAGGED_PTR_H
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER >= 26
+  
+#include <__config>
+#include <__type_traits/is_trivially_copyable.h>
+#include <__assert>
+#include "__bit/has_single_bit.h"
----------------
ldionne wrote:

```suggestion
#include <__bit/has_single_bit.h>
```

https://github.com/llvm/llvm-project/pull/111861