sub hpairs (\%) {
    use enum 'KEY', 'VAL';
    my $href = shift;
    map[ each %$href ], 1 .. keys %$href;
}

my %salary = (
    boss      => 1_000,
    secretary => 300,
    admin     => 600,
    janitor   => 150,
);

print for map {
    "$_->[KEY] earns $_->[VAL]"
} sort {
    $a->[VAL] <=> $b->[VAL]
} grep {
    $_->[VAL] > 500
} hpairs %salary;