sub _share {
            
    my $it = shift;
    my $ref = ref $it;

    if ($ref eq 'SCALAR') {
        tie ${$it},'threads::shared',{},${$it};
    } elsif ($ref eq 'ARRAY') {
        tie @{$it},'threads::shared',{},@{$it};
    } elsif ($ref eq 'HASH') {
        tie %{$it},'threads::shared',{},%{$it};
    } elsif ($ref eq 'GLOB') {
        tie *{$it},'threads::shared',{},*{$it};
    } else {
        _croak( "Don't know how to share '$it'" );
    }
} #_share