package My::This;
sub thing { print 'This' }

package My::That;
sub thing { print 'That' }

package main;
&My::This::thing; # prints This
&My::That::thing; # prints That

##</code><code>##

package My::This;
sub new { bless {} }
sub thing { print 'This' }

package My::That;
sub new { bless {} }
sub thing { print 'That' }

package main;
my $This = My::This->new();
my $That = My::That->new();
$This->thing; # prints This
$That->thing; # prints That