add a warning note

tbrowder · web-flow · commit c46235e8c387 · 2019-02-10T06:15:03.000-06:00
diff --git a/doc/Language/hashmap.pod6 b/doc/Language/hashmap.pod6
@@ -147,7 +147,9 @@ or even
     
 or  
 
-    my %h = [ a => 'b', c => 'd', e => 'f' ];
+    my %h = [ a => 'b', c => 'd', e => 'f' ]; # This format is NOT recommended.
+                                              # It cannot be a constant and there
+                                              # will be problems with subhashes.
 
 or
 
