Hi All, I am new to boost and haven't done much c++ programming in the last couple years, so apologies if this question is obvious. I'm looking at dynamic_bitset to build a translator between the bits and NMEA string packaging for Maritime AIS. Basically this is each character in a string represents 6 bits of data. I'd like to make two lookup tables that let me go back and forth quickly between bitsets and the NMEA ASCII. My dynamic_bitset questions are: * how can I best concatenate multiple dynamic_bitsets? For example: lookupbits['a']+lookupbits['1']+lookupbits['g'] would return a dynamic_bitset of 18 bits. I'm looking for some sort of join operation and append does not seem to do what I want. * How can I best slice the results? If I know that, for example, and unsigned integer is at bits 11-14, is there way to do quickly get a dynamic_bitset of those bits? I've got all this working in pure python, but it is way to slow ( http://vislab-ccom.unh.edu/~schwehr/software/noaadata/ in the ais package). Any suggestions would be greatly appreciated. Thanks! -kurt http://schwehr.org