With perl 5.10 you can do this

use 5.010_000;

my %humbug = (
    foo => 'bar',
    fu  => 'bah',
);

$_ = 'humbug';

say;
foreach my $key ( keys %humbug ) {
    given ( $log{$key} ) {
        say if $_;
    }
}
say;

__END__
humbug
bah
bar
humbug
[download]

It doesn't work for delete , see BrowserUK's explanation.