Make the old class name available as an alias.

diff --git a/include/deal.II/base/smartpointer.h b/include/deal.II/base/smartpointer.h
new file mode 100644 (file)
index 0000000..3865be6
--- /dev/null
+++ b/include/deal.II/base/smartpointer.h
@@ -0,0 +1,35 @@
+// ------------------------------------------------------------------------
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+// Copyright (C) 1998 - 2023 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// Part of the source code is dual licensed under Apache-2.0 WITH
+// LLVM-exception OR LGPL-2.1-or-later. Detailed license information
+// governing the source code and code contributions can be found in
+// LICENSE.md and CONTRIBUTING.md at the top level directory of deal.II.
+//
+// ------------------------------------------------------------------------
+
+#ifndef dealii_smartpointer_h
+#define dealii_smartpointer_h
+
+
+#include <deal.II/base/observer_pointer.h>
+
+DEAL_II_NAMESPACE_OPEN
+
+/**
+ * A type alias for the ObserverPointer class that makes sure the previous
+ * name of the class, SmartPointer, continues to be available.
+ *
+ * @deprecated Use the new name of the class, ObserverPointer, instead.
+ */
+template <typename T, typename P = void>
+using SmartPointer DEAL_II_DEPRECATED_EARLY_WITH_COMMENT(
+  "Use the new name of the class, ObserverPointer.") = ObserverPointer<T, P>;
+
+DEAL_II_NAMESPACE_CLOSE
+
+#endif