No, don't do that.

Assume that UNIVERSAL::new existed. Would you suggest always creating objects with UNIVERSAL::new( $class_name, %data ); too?

Try instead:

my $is_node = eval { $value->isa( 'Node' ) };
# handle not node case if $@ is true or if $is_node is false
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This has the advantage of allowing subclasses of Node to override isa() as they see fit, of allowing objects that perform the Node role (see Class::Roles, for example) to work appropriately, and of catching an error if $value is an invalid invocant. It also avoids calling a parent class method specifically on a potential instance of a derived class, which is a bad idea.

Update: Expanded code slightly.

No don't do this either. An exception should only be used to catch exceptional events. Since it seems that $value is just as likely not to be a 'Node' as it is to be one you should not use an exception to test it.
-- gam3
A picture is worth a thousand words, but takes 200K.

As I mentioned, if $value is not a valid invocant, it is an exceptional case.

I'm not aware of any other idiom that respects potentially-overridden isa() methods and handles potentially invalid invocants in one statement. If you know one, please share.

Scalar::Util's blessed() is pretty good, but that technique disallows calling isa() as a class method. Sometimes that's good. Sometimes it's not.

Thank you, this is exactly what I wanted. You get my ++ for answering the question. But after reading revdiablo's post below, I'm not sure if this is really what I want anymore. Maybe I'll have to spend some time rethinking my design.

    -Bryan

Every time a module does that a kitten using Test::MockObject dies.

Please think of the kittens!

Perhaps the kitten should choose a better way of mocking then. I suggest using the Parisian::Waiter::Scornful module.

Perhaps not a better way of mocking, but a better way of introspecting.... I uploaded a new module that hacks around this stuff.
-nuffin
zz zZ Z Z #!perl