Bugs item #798357, was opened at 2003-09-01 02:57 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=798357&group_id=7586
Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Derrick Bass (derrickbass) Assigned to: Nobody/Anonymous (nobody) Summary: rational operator< can overflow Initial Comment: I recently discovered that the operator< for the rational template is prone to overflow. It is noted in the design documentation that some care was taken to prevent overflows for most operators, but apparently not for this one. The basic problem comes from the fact that it checks if n1/d1 is less than n2/d2 by checking if n1 d1 < n2 d1. Those products can easily overflow. I suggest an algorithm that first checks the integer parts of the quotients. If they are equal, then the algorithm could be based on the observation: for n1<d1 and n2<d2 and everything positive and d1<d2, then n1/d1 < n2/d2 iff n1/d1 < n2-n1/d2-d1. So if we write d2 = q d1 + r then n1/d1 < n2/d2 iff n1/d1 < n2-q n1/r One would then recursively check this inequality. Obviously, a similar observation would have to be made for d2<d1. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=798357&group_id=7586 ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ Boost-bugs mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/boost-bugs _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
