moosex-types.pl

package App::TypesLibrary;
use URI;
use MooseX::Types -declare => [qw/
    Uri
/];

# imports moose types
use MooseX::Types::Moose qw/Str Object/;

# note that syntax differs from the one when
# using Moose::Util::TypeConstraints
subtype Uri,
    as Object;

coerce Uri,
    from Str,
    via { URI->new($_) };

package App::Fetch;
use Moose;
use TypesLibrary 'Uri';

use Data::Dump 'dump';

sub fetch {
    my ($self, $url) = @_;

    if (! is_Uri($url)) {
        $url = to_Uri($url)
    }

    # no we have URI class instance in $url
    dump $url;
}

package main;

my $app = App::Fetch->new;
$app->fetch('www.google.com');