--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_JOURNAL_TYPE_TRAITS_H
+#define CEPH_LIBRBD_JOURNAL_TYPE_TRAITS_H
+
+namespace journal {
+class Future;
+class Journaler;
+class ReplayEntry;
+}
+
+namespace librbd {
+namespace journal {
+
+template <typename ImageCtxT>
+struct TypeTraits {
+ typedef ::journal::Journaler Journaler;
+ typedef ::journal::Future Future;
+ typedef ::journal::ReplayEntry ReplayEntry;
+};
+
+} // namespace journal
+} // namespace librbd
+
+#endif // CEPH_LIBRBD_JOURNAL_TYPE_TRAITS_H