Hi, I'm parsing with Spirit strings of numeric values and want to guess the right POD that can fit all of them. For example, I see at glance sets with only 0.0 and 1.0, that can be optimized to a adjacent group of bool: 1. Or some doubles, in another set, which value ranges and resolution like shorts. Or if something like "0.000000000000000000000001" will fit exactly in my floats. I'm reading boost/lexical_cast , numeric/conversion and interval docs, but still don't found a way to convert strings to POD knowing if that cast is exact or not. Range check is there, but don't find a test telling me if that cast was exact. The 'exact' term here is what boost::numeric doc definitions chapter means. Thanks, alef -- Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer