K-T Thanks - it is very helpful! > BTW, while poking through things, I noticed css/IntPair. > Why not just use std::pair<int, int>? I need to pass the pair over through swig to python, and I am afraid of running into mysterious problems with swig (like the one I just run into), so I felt safer creating my own super simple class instead of using std::pair. If you think std::pair won't give me any troubles with swig, I am happy to switch. Jacek ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the QSERV-L list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=QSERV-L&A=1