Added class attributes

Author: teodozjan

lib/Language/classtut.pod

@@ -166,6 +166,37 @@ X<|traits, is rw>
 The C<is rw> trait causes the generated accessor method to return something
 external code can modify to change the value of the attribute.
 
+=head1 Static fields?
+
+Perl6 has no B<static> keyword. Anyway any class may declare anything that
+module can so making a scoped variable sounds like good idea.
+
+       class Singleton {
+    
+		my Singleton $instance; 
+    		method new {!!!} # Singleton.new dies.
+    		submethod instance {
+		  $instance = Singleton.bless unless $instance;
+		  $instance;
+       		}
+       }
+ 
+Class attributes defined by L<my> or L<our> may also be initialized while 
+declaration but we are implementing Singleton pattern here and object must 
+be created during first use. It is not possible to predict in 100% the moment 
+when attribute initialization will be executed  because it can be done during 
+compilation, runtime or both especially when importing class using L<use> 
+keyword.
+
+	class HaveStaticAttr {
+	      my Foo $.foo = some_complicated_subroutine; 
+	}
+
+Class attributes may also be declared with secondary sigil like object 
+attributes that will result in generating read-only accessor if attribute 
+is to be public.
+ 
+
 =head1 Methods
 
 X<|methods>