diff --git a/src/hb-map.hh b/src/hb-map.hh
index 82fa3ccf8..84fe1d549 100644
--- a/src/hb-map.hh
+++ b/src/hb-map.hh
@@ -177,6 +177,7 @@ struct hb_hashmap_t
   }
 
   bool is_empty () const { return population == 0; }
+  explicit operator bool () const { return !is_empty (); }
 
   unsigned int get_population () const { return population; }
 
diff --git a/src/hb-set.hh b/src/hb-set.hh
index 3b100f609..ae8b5eb10 100644
--- a/src/hb-set.hh
+++ b/src/hb-set.hh
@@ -273,6 +273,7 @@ struct hb_set_t
 	return false;
     return true;
   }
+  explicit operator bool () const { return !is_empty (); }
 
   void dirty () { population = UINT_MAX; }