Some of you have noted (with displeasure) the ugly display of floating point values from BOOST_CHECK_CLOSE for example difference between +1e-6{9.9999999999999995e-007} and 1e-5{1.0000000000000001e-005} exceeds 2.22045e-018% The number of decimal digits used is enough to show all that can be significant. For 64-bit doubles it is 17 decimal digits, (for 32-bit float 9) and for long double, quad_float even more. This is undoubtedly ugly, but has the virtue that it avoids apparently nonsensical displays like 1.000000 != 1.000000 when comparing 1.f, with the next after, one least significant bit above 1.00000012f, which is what you get if the standard 6 decimal digits for float is used. It has another great virtue - it highlights the limitations of storing decimal representations in binary. There are smarter algorithms for display (which Gennadiy is considering), but IMO this is the C++ standard way of doing these things and I suggest that this is the Right Thing To Do in this case. Are there any dissenting views? Paul -- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB Phone and SMS text +44 1539 561830, Mobile and SMS text +44 7714 330204 mailto: pbristow@hetp.u-net.com http://www.hetp.u-net.com/index.html http://www.hetp.u-net.com/Paul%20A%20Bristow%20info.html