package MyClass;
use Moose;
use Moose::Util::TypeConstraints;

subtype 'StringWithDashes'
    => as 'Str'
    => where { /^[\w-]+$/ };

has 'fname' => (
    is => 'rw',
    isa => 'StringWithDashes'
);

has 'lname' => (
    is => 'rw',
    isa => 'StringWithDashes'
);