in reply to Re^2: Uses for an lvalue subroutine
in thread Uses for an lvalue subroutine

That's twisted and clever. One question: what is the intent of the ||= undef, other than changing $self->{$AUTOLOAD} to undef if it's 0 or ""? 
my ($object) = new Object;

$object->whatever(0);
print "Whatever is '",$object->whatever(),"'\n";     # Oops!

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Re^4: Uses for an lvalue subroutine
by tadman (Prior) on Jan 11, 2001 at 02:14 UTC
    chipmunk points out something that I had failed to test for. In my effort to reduce the code down to a minimum, that case slipped right through my logic. Here's Take II, new and improved support for 0 and "" added: 
    
sub AUTOLOAD : lvalue
{
        my ($self) = shift;

        $AUTOLOAD =~ s/.*://;

        @_?
                $self->{$AUTOLOAD} = shift 
                : !defined($self->{$AUTOLOAD})?
                        $self->{$AUTOLOAD} = undef 
                        : $self->{$AUTOLOAD};
}
    The reason for having $self->{$AUTOLOAD} = undef is to give the caller something to assign to. Returning an invalid hash entry will cause an assignment error. 'undef' is not a valid lvalue, but returning a reference to a variable which may have a value of 'undef' is acceptable.

    BTW, I've never had to indent my '?:'s before, but it was the only way to make how this worked clear(er).
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