package Foo;

use base qw( ExporterAttributes );

my $PI : Export_Ok = 3.14;

sub utility : Export_Ok Export_Group(general) {...}
sub another : Export_Ok Export_Group(general) {...}

1;

...

use Foo qw( :GENERAL );
utility($bar);

##</code><code>##

package Foo;

use base qw( ExporterAttributes );
use Readonly;

my $PI : Export_Ok(PI);
Readonly $PI => 3.14;

sub utility : Export_Ok(utility) Export_Group(general) {...}
sub another : Export_Ok(another) Export_Group(general) {...}

1;