change return type.

src/wrapper.hh

@@ -126,8 +126,9 @@ public:
     public:
         iterator() = default;
         
-        iterator operator++() { return (value ? value = value->next : value); }
-        Element  operator*()  { return value->*LW::Value; }
+        iterator operator++()  { return (value ? value = value->next : value); }
+        Element   operator*()  { return value->*LW::Value; }
+        Element  operator->() { return (value->*LW::Value); }
         bool     operator==(const iterator& other) const { return value == other.value; }
         bool     operator!=(const iterator& other) const { return value != other.value; }