# 2 bits: 3
@@define BITS_2_D ([0-3])
# 3 bits: 7
@@define BITS_3_D ([0-7])
# 4 bits: 15
@@define BITS_4_D ([[:digit:]]|1[0-5])
# 5 bits: 31
@@define BITS_5_D ([12]?[[:digit:]]|3[01])
# 6 bits: 63
@@define BITS_6_D ([1-5]?[[:digit:]]|6[0-3])
# 7 bits: 127
@@define BITS_7_D ([[:digit:]]{1,2}|1([01][[:digit:]]|2[0-7]))
# 8 bits: 255
@@define BITS_8_D (1?[[:digit:]]{1,2}|2([0-4][[:digit:]]|5[0-5]))
# 9 bits: 511
@@define BITS_9_D ([1-4]?[[:digit:]]{1,2}|5(0[[:digit:]]1[0-1]))

# 10 bits: 1023
@@define BITS_10_D ([[:digit:]]{1,3}|10([0-1][[:digit:]]|2[0-3]))
# 11 bits: 2047
@@define BITS_11_D (1?[[:digit:]]{1,3}|20([0-3][[:digit:]]|4[0-7]))
# 12 bits: 4095
@@define BITS_12_D ([[1-3]?[[:digit:]]{1,3}|40([0-8][[:digit:]]|9[0-5]))
# 13 bits: 8191
@@define BITS_13_D ([[1-7]?[[:digit:]]{1,3}|8(0[[:digit:]]{2}|1([0-8][[:digit:]]|9[01])))
# 14 bits: 16383
@@define BITS_14_D ([[:digit:]]{1,4}|1([0-5]?[[:digit:]]{3}|6([012][[:digit:]]{2}|3([0-7][[:digit:]]|8[0123]))))
# 15 bits: 32767
@@define BITS_15_D ([12]?[[:digit:]]{1,4}|3([01]?[[:digit:]]{3}|2([0-6][[:digit:]]{2}|7([0-5][[:digit:]]|6[0-7]))))
# 16 bits: 65535
@@define BITS_16_D ([12345]?[[:digit:]]{1,4}|6([0-4]?[[:digit:]]{3}|5([0-4][[:digit:]]{2}|5([0-2][[:digit:]]|3[0-5]))))
# 17 bits: 131072
@@define BITS_17_D ([[:digit:]]{1,5}|1([012][[:digit:]]{4}|3(0[[:digit:]]{3}|10([0-6][[:digit:]]|7([01])))))
# 18 bits 262144
@@define BITS_18_D (1?[[:digit:]]{1,5}|2([012345][[:digit:]]{4}|6([01][[:digit:]]{3}|2(0[[:digit:]]{2}|1([0-3][[:digit:]]|4[0-3])))))
# 19 bits: 524288
@@define BITS_19_D ([1234]?[[:digit:]]{1,5}|5([01][[:digit:]]{4}|2([0-3][[:digit:]]{3}|4([01][[:digit:]]{2}|2([0-7][[:digit:]]|8[0-])))))
# 20 bits: 1048576
@@define BITS_20_D ([[:digit:]]{1,6}|10([0123][[:digit:]]{4}|4([0-7][[:digit:]]{3}|8([0-4][[:digit:]]{2}|5([0-6][[:digit:]]|7[0-5])))))
# 21 bits: 2097152
@@define BITS_21_D (1?[[:digit:]]{1,6}|20([0-8][[:digit:]]{4}|9([0-6][[:digit:]]{3}|7(0[[:digit:]]{2}|1([0-4][[:digit:]]|5[01])))))

# if you want more please send a patch. the _X suffix is reserved for hex.
