constructor returns an object not isa('CHI')

[ether]

perl -MCHI -MScalar::Util=blessed -wle'print blessed(CHI-
>new(driver=>"File"))'
Moose::Meta::Class::__ANON__::SERIAL::1

perl -MCHI -MScalar::Util=blessed -wle'print CHI-
>new(driver=>"File")->isa("CHI")'
<false>

Since CHI.pm is empty except for its constructor, would it be a
problem to
create the anonymous class using both the driver and CHI itself as
superclasses,
so that attribute declarations such as this would pass type
constraints?

has cache => (
is => 'ro',
isa => 'CHI',
lazy => 1,
default => sub { CHI->new(driver => shift->driver) },
);

[Jonathan Swartz]

Is there a problem with doing this instead:

isa => 'CHI::Driver'

> Since CHI.pm is empty except for its constructor, would it be a
> problem to
> create the anonymous class using both the driver and CHI itself as
> superclasses,
> so that attribute declarations such as this would pass type
> constraints?
>
> has cache => (
> is => 'ro',
> isa => 'CHI',
> lazy => 1,
> default => sub { CHI->new(driver => shift->driver) },
> );
>

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[Karen Etheridge]

On Sun, Feb 19, 2012 at 07:04:32AM -0800, Jonathan Swartz wrote:
> Is there a problem with doing this instead:
>
> isa => 'CHI::Driver'

It depends on how you define "problem". :) It's generally considered bad
practice for a constructor to return an object not of the same type as the
class it was constructed from -- it violates the principle of least
surprise.