Subject: Re: [boost] Fixed point integer proposal
From: John Bytheway (jbytheway+boost_at_[hidden])
Date: 2009-06-25 15:51:12
Phil Endecott wrote:
> Soren Holstebroe wrote:
>> In my template N bit x N bit equals N bit per default.
>
> Which of the 2N possible bits do you keep, and which do you discard?
>
> I chose to try to behave as closely as possible to how built-in integer
> types work. If I multiply uint8_t * uint8_t and assign the result to a
> uint32_t, it works.
Yes, but if you multiply a uint32_t by a uint32_t and assign to a
uint64_t, then it doesn't work (assuming int == uint32_t). Do you want
a fixed point library to mimic these apparent inconsistencies? It would
probably make it less portable, since sizeof(int) isn't the same everywhere.
John Bytheway