DB<217> map { /(1\d*)/;$1 } 5..15
 => (undef, undef, undef, undef, undef, 10, 11, 12, 13, 14, 15)

  DB<218> map { /(1\d*)/ } 5..15
 => (10, 11, 12, 13, 14, 15)