show how to test for classness and enumness

doc/Language/typesystem.pod6

@@ -75,6 +75,17 @@ compiler will check at the end of the current scope if the type is defined.
 
 TODO
 
+=head3 Introspection
+
+=head4 Metaclass
+
+To test if a given type object is a class test the meta object method C<.HOW>
+for L</type/Metamodel::ClassHOW>.
+
+    class C {};
+    say C.HOW ~~ Metamodel::ClassHOW;
+    # OUTPUT«True␤»
+
 =head3 Attributes
 
 =head4 Private Attributes
@@ -436,6 +447,17 @@ package, we can get a list of type objects for the keys.
     enum E(<one two>); dd E::.values;
     # OUTPUT«(E::two, E::one).Seq␤»
 
+=head3 Introspection
+
+=head4 Metaclass
+
+To test if a given type object is an enum test the meta object method C<.HOW>
+for L</type/Metamodel::EnumHOW>.
+
+    enum E(<a b c>);
+    say E.HOW ~~ Metamodel::EnumHOW;
+    # OUTPUT«True␤»
+
 =head3 Methods
 
 =head4 method enums