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| author | Tony Bowden <tony@kasei.com> | 2001-08-25 16:13:14 +0100 |
|---|---|---|
| committer | Abhijit Menon-Sen <ams@wiw.org> | 2001-08-25 18:28:43 +0000 |
| commit | 04b85669c399942716cc222829b1dae05a1ed7c2 (patch) | |
| tree | 392a127f9b25c9243866ca12a0038fe692ab7cb8 /lib | |
| parent | acbe17fc4e3c447b48d980c85cdc81b3190f66eb (diff) | |
| download | perl-04b85669c399942716cc222829b1dae05a1ed7c2.tar.gz | |
Re: 'can' with undefined subs
Message-Id: <20010825151314.B11788@soto.kasei.com>
p4raw-id: //depot/perl@11751
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/UNIVERSAL.pm | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/UNIVERSAL.pm b/lib/UNIVERSAL.pm index a66f8d5328..a9cb478b43 100644 --- a/lib/UNIVERSAL.pm +++ b/lib/UNIVERSAL.pm @@ -45,6 +45,15 @@ C<can> checks if the object has a method called C<METHOD>. If it does 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 ] ) |