[Boost-users] Determining offset of regex syntax errors

Members of class reg_expression know where they are up to while compiling, but don't include that information when they throw. It can be pretty daunting to get the "Invalid regular expression" error message, with no indication of where to start looking, so I'd like to be more helpful. Given the character offset from the start of the RE, I can put the cursor there. Any suggestions as to how to obtain that information? Thanks, Keith MacDonald