Author: autrijus
Date: Sat Apr 1 20:46:57 2006
New Revision: 8533
Modified:
doc/trunk/design/syn/S13.pod
Log:
* S13: specify type casting in the form of
multi submethod *infix:<as>
which usually only cares about the class of its second invocant.
Modified: doc/trunk/design/syn/S13.pod
==============================================================================
--- doc/trunk/design/syn/S13.pod (original)
+++ doc/trunk/design/syn/S13.pod Sat Apr 1 20:46:57 2006
@@ -116,3 +116,17 @@
this hash over a lexical scope, so you could have different policies
on magical autogeneration. The default mappings correspond to the
standard fallback mappings of Perl 5 overloading.
+
+=head1 Type Casting
+
+A class can use the C<< *infix:<as> >> submethod to declare that its objects
+can be casted to some other class:
+
+ multi submethod *infix:<as> (IO) { $*OUT }
+ multi submethod *infix:<as> (Int) { 1 }
+ multi submethod *infix:<as> (Str) { "Hello" }
+
+With the above declaration, C<$obj as "foo"> is equivalent to C<$obj as Str>,
+because the multi dispatch cares only about the class.
+
+=cut
