Merge pull request #19 from kanatohodets/master

Fix up classtut example

Author: Mouq

lib/Language/classtut.pod

@@ -17,10 +17,12 @@ result is interesting and, at times, useful.
         has Task @!dependencies;
         has Bool $.done;
 
-        method new(&callback, Task *@dependencies) {
+        method new(&callback, *@dependencies) {
             return self.bless(:&callback, :@dependencies);
         }
 
+        submethod BUILD(:&!callback, :@!dependencies) { }
+
         method add-dependency(Task $dependency) {
             push @!dependencies, $dependency;
         }
@@ -253,6 +255,21 @@ into the C<@dependencies> slurpy array and passes them as named parameters to
 C<bless> (note that C<:&callback> uses the name of the variable--minus the
 sigil--as the name of the parameter).
 
+X<|BUILD>
+
+Private attributes really are private. This means that C<bless> is not allowed
+to bind things to C<&!callback> and C<@!dependencies> directly. To do this, we
+override the C<BUILD> submethod, which is called on the brand new object by
+C<bless>:
+
+    submethod BUILD(:&!callback, :@!dependencies) { }
+
+Since C<BUILD> runs in the context of the newly created C<Task> object, it is
+allowed to manipulate those private attributes. The trick here is that the
+private attributes (C<&!callback> and C<&!dependencies>) are being used as the
+bind targets for C<BUILD>'s parameters. Zero-boilerplate initialization! See
+L<objects|/language/objects#Object Construction> for more information.
+
 =head1 Consuming our class
 
 After creating a class, you can create instances of the class.  Declaring a