Change 11751 by ams@ams-lustre on 2001/08/25 18:28:43
Subject: Re: 'can' with undefined subs
From: Tony Bowden <[EMAIL PROTECTED]>
Date: Sat, 25 Aug 2001 15:13:14 +0100
Message-Id: <[EMAIL PROTECTED]>
Affected files ...
... //depot/perl/lib/UNIVERSAL.pm#10 edit
Differences ...
==== //depot/perl/lib/UNIVERSAL.pm#10 (text) ====
Index: perl/lib/UNIVERSAL.pm
--- perl/lib/UNIVERSAL.pm.~1~ Sat Aug 25 12:45:05 2001
+++ perl/lib/UNIVERSAL.pm Sat Aug 25 12:45:05 2001
@@ -45,6 +45,15 @@
then a reference to the sub is returned. If it does not then I<undef>
is returned.
+C<can> cannot know whether an object will be able to provide a method
+through AUTOLOAD, so a return value of I<undef> does not necessarily mean
+the object will not be able to handle the method call. To get around
+this some module authors use a forward declaration (see L<perlsub>)
+for methods they will handle via AUTOLOAD. For such 'dummy' subs, C<can>
+will still return a code reference, which, when called, will fall through
+to the AUTOLOAD. If no suitable AUTOLOAD is provided, calling the coderef
+will cause an error.
+
C<can> can be called as either a static or object method call.
=item VERSION ( [ REQUIRE ] )
End of Patch.
