set/dset: add scalar add

set/dset.hpp

@@ -64,6 +64,12 @@ namespace cruft::set {
             m_size += count;
         }
 
+        /// Add the value to the set
+        void add (ValueT const &val)
+        {
+            return add (1, val);
+        }
+
         /// A list of items to remove from this store.
         ///
         /// Items must be in sorted order, and must be a subset of this