--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcxx/include/__assert	Wed Nov 09 17:45:10 2022 +0900
@@ -0,0 +1,59 @@
+// -*- 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___ASSERT
+#define _LIBCPP___ASSERT
+
+#include <__config>
+#include <__verbose_abort>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+// This is for backwards compatibility with code that might have been enabling
+// assertions through the Debug mode previously.
+// TODO: In LLVM 16, make it an error to define _LIBCPP_DEBUG
+#if defined(_LIBCPP_DEBUG)
+# ifndef _LIBCPP_ENABLE_ASSERTIONS
+#   define _LIBCPP_ENABLE_ASSERTIONS 1
+# endif
+#endif
+
+// Automatically enable assertions when the debug mode is enabled.
+#if defined(_LIBCPP_ENABLE_DEBUG_MODE)
+# ifndef _LIBCPP_ENABLE_ASSERTIONS
+#   define _LIBCPP_ENABLE_ASSERTIONS 1
+# endif
+#endif
+
+#ifndef _LIBCPP_ENABLE_ASSERTIONS
+# define _LIBCPP_ENABLE_ASSERTIONS _LIBCPP_ENABLE_ASSERTIONS_DEFAULT
+#endif
+
+#if _LIBCPP_ENABLE_ASSERTIONS != 0 && _LIBCPP_ENABLE_ASSERTIONS != 1
+# error "_LIBCPP_ENABLE_ASSERTIONS must be set to 0 or 1"
+#endif
+
+#if _LIBCPP_ENABLE_ASSERTIONS
+# define _LIBCPP_ASSERT(expression, message)                                        \
+    (__builtin_expect(static_cast<bool>(expression), 1) ?                           \
+      (void)0 :                                                                     \
+      ::std::__libcpp_verbose_abort("%s:%d: assertion %s failed: %s", __FILE__, __LINE__, #expression, message))
+#elif !defined(_LIBCPP_ASSERTIONS_DISABLE_ASSUME) && __has_builtin(__builtin_assume)
+# define _LIBCPP_ASSERT(expression, message)                                        \
+    (_LIBCPP_DIAGNOSTIC_PUSH                                                        \
+    _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wassume")                                    \
+    __builtin_assume(static_cast<bool>(expression))                                 \
+    _LIBCPP_DIAGNOSTIC_POP)
+#else
+# define _LIBCPP_ASSERT(expression, message) ((void)0)
+#endif
+
+#endif // _LIBCPP___ASSERT