1 files changed, 15 insertions, 0 deletions
diff --git a/odb/mssql/mssql-types.hxx b/odb/mssql/mssql-types.hxx
index 43e6d6e..9f3d1be 100644
--- a/odb/mssql/mssql-types.hxx
+++ b/odb/mssql/mssql-types.hxx
@@ -141,6 +141,21 @@ namespace odb
                         // value 8 indicates the SMALLDATETIME type
                         // which has no seconds.
     };
+
+    // An instance of this structure specifies the function to invoke and
+    // the context to pass when the object/view image is about to be
+    // modified. This mechanism is used by the query machinery to save the
+    // image between result iteration and dereferencing if something gets
+    // executed between these two operations that would overwrite the
+    // image.
+    //
+    struct change_callback
+    {
+      change_callback (): callback (0), context (0) {};
+
+      void (*callback) (void*);
+      void* context;
+    };
   }
 }