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sub sieve {
  my @pats = UNIVERSAL::isa($_[0], 'Regexp') ? @_ : map(qr/$_/, @_);
...
my %tapes = (...);
my $c5p5 = sieve(qr/-C5$/, qr/-P5$/);
my @sorted_keys = $c5p5->(sub { $tapes{$_} }, keys %tapes);