package MyApp::User;
use strict;
use overload
    '""' => \&stringify,
    'eq' => \&cmp,
    ;

sub new {
    my( $class, %options )= @_;
    bless \%options => $class;
};

sub stringify {
    my( $self )= @_;
    colorize( $self->{ name }, 'red' );
};

sub cmp {
    ...
};