----- Original Message ----- From: "Kevin Atkinson" <[EMAIL PROTECTED]> To: "Boost mailing list" <[EMAIL PROTECTED]> Sent: Saturday, March 01, 2003 12:03 AM Subject: Re: [boost] Is there any Interest in a Fixed Point Library?
> On Fri, 28 Feb 2003, Stephen Nutt wrote: > > > Kevin, > > > > I started on this must be close to a year ago, and I got wrapped up with > > other stuff and never got back to it. > > Well I don't have a large interest in it beyond simple arithmetic. The > main reason that I wrote is to avoid having to deal with portably sending > floating point numbers over the network. With integers all I have to > worry about is endian order. > > > One nifty option was to specify what would happen on overflow. There were > > two choices. Either the number would not overflow but go to its limit, or > > it would overflow in the 'expected' way. > > Yes I know what you mean. The problem is doing it efficiently. > Efficiency was one key aspect of my design. So I used trait classes to handle the arithmetic. This way you could either use the highly efficent overflow traits (should be as efficient as doing fixed point arithmetic without a template with a decent compiler), or use the saturation traits class, which will increase compiled code size and reduce speed. Althought I don't need the saturation aspect for my purposes, fot the template class to be useful for the embedded folks, it seemed to be necessary. > > fixed <int, 6> a = val1; > > fixed <char, 3> b = val2; > > fixed <long, 9> = a + b; > > > > without loss of precision. > > Can you post the implementation? > I'll take a look for it and see if I can clean it up a little. I'll try and post it by the end of the weekend. > -- > http://kevin.atkinson.dhs.org > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
