Johan: you can construct an iterator wrapper that map operator++ to next(float), and then it *really* is the specialization of std::distance() for this iterator type. In my opinion, difference implies an algebraic structure (which there is on float, but not what you want). I hope this convinces you that distance is the right name. HB Sent via BlackBerry from T-Mobile -----Original Message----- From: Johan Råde <rade@maths.lth.se> Date: Mon, 05 May 2008 17:10:09 To:boost@lists.boost.org Subject: Re: [boost] [Math/nextafter] A question of naming functions... John Maddock wrote:
So, it looks like so far we have:
next(val) prior(val)
and either of
representation_distance(a, b); discrete_distance(a, b);
I'm still a bit unhappy about calling a signed quantity a "distance". I would prefer "difference". Let me elaborate: To me a "distance" is a quantity that satisfies the rules: d(x,y) >= 0 d(x,x) = 0 d(y,x) = d(x,y) d(x,y) + d(y,z) >= d(x,z) while a "difference" is a quantity that satisfies the rules d(x,x) = 0 d(y,x) = -d(x,y) d(x,y) + d(y,z) = d(x,z) The function we are discussing satisfies the second set of rules. --Johan _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost