On Thu, 3 Aug 2006 19:14:19 +0100, "John Maddock" <john@johnmaddock.co.uk> wrote:
Apparently this was not quite as simple as I thought it was, because we still need to handle the 0/0 case, the following patch does the trick:
Sorry to jump in at the latest moment. I wasn't following this thread (it's interesting, but time is limited :-()
cvs diff: Diffing boost/test Index: boost/test/floating_point_comparison.hpp [...] } + else if(f1 == 0) + { + // Avoid 0 / 0, since we're calculating relative error
Shouldn't the comment read 0/x or 0/anything?
+ // the result really is zero here no matter what the denominator:
Unless the denominator is zero, in which case returning zero is a convention.
+ return 0; + } + else if(f2 == 0) + { + // We have an infinite relative error, in practice any + // big number returned here will cause our test to fail: + return 1000000; // any really big number will do.
Could you please clarify the context a bit? Would this, in general, be called also when numeric_limits is not specialized? When a specialization exists I would return (std::numeric_limits<>::max)(); when it doesn't, how can one be sure that an FPT can be constructed from the integer 1000000? Sorry if this is just noise; I just thought better *I* raise some noise now than some executable somewhere will do it later :-) -- [ Gennaro Prota, C++ developer for hire ]