John Maddock writes:
Gennadiy Rozental wrote:
Which particular words/statements you are having difficulties with?
The problem for me is that it's too easy to forget that BOOST_CHECK_CLOSE refers to a persentage and not a relative error. I've lost count of how many times I've made that mistake, even though I do understand what it does.
BOOST_CHECK_CLOSE_FRACTION is an improvement, but still doesn't spell out what it does.
Personally I would have liked these to have been really explicit:
BOOST_CHECK_PERSENTAGE_DIFFERENCE BOOST_CHECK_RELATIVE_DIFFERENCE BOOST_CHECK_EPSILON_DIFFERENCE
Exactly. I suspect the various grumblings that Gennadiy hears about this topic has much more to do with a mismatch between names and people's expectations than any fundamental problems.
To put things another way: how many people do you expect to thinking in terms of persentage differences between floating point numbers? I'm afraid we (mostly) all think in terms of epsilon units, and once in that mind set, converting to persentages just doesn't come naturally.
Right. At least, that's true of people like me who do mathematical stuff. Maybe there are vast herds of C++ programmers out there who think in terms of percentage tolerance, though. I'm not saying it was necessarily a bad design problem. It's a (mildly) bad design for what _I_ want, but then, I'm wrapping the whole unit test library up in my own interface anyway. :-) ---------------------------------------------------------------------- Dave Steffen, Ph.D. Disobey this command! Software Engineer IV - Douglas Hofstadter Numerica Corporation dg@steffen a@t numerica d@ot us (remove @'s to email me)