crimson: facilitate errorator extending with new errors.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>

diff --git a/src/crimson/common/errorator.h b/src/crimson/common/errorator.h
index 3a639c2a7ba1a271b2787895e9735078f288fc9f..b3b7cddc575b61eb739531f27362620ff2db737c 100644 (file)
--- a/src/crimson/common/errorator.h
+++ b/src/crimson/common/errorator.h
@@ -293,6 +293,11 @@ struct errorator {
     }
   };
 
+  // get a new errorator by extending current one with new error
+  template <class... NewWrappedAllowedErrorsT>
+  using extend = errorator<WrappedAllowedErrorsT...,
+                           NewWrappedAllowedErrorsT...>;
+
 private:
   struct ignore_marker_t{};