Boost logo

Boost :

Subject: Re: [boost] [review][constrained_value] Review of Constrained Value Library begins today
From: Johan RÃ¥de (rade_at_[hidden])
Date: 2008-12-11 11:07:48

Steven Watanabe wrote:
> Johan RÃ¥de wrote:
>> Imagine the following case,
>> 1) x and y are stored in 80-bit registers
>> 2) x < y
>> 3) both x and y are just below 1.0,
>> so close that they would be rounded to 1.0 if truncated to 64 bits
>> If now x is truncated to 64 bits, and then moved back to an 80-bit
>> register,
>> while y is unchanged, then x > y.
> In other words, we always have to force at least one of x and y to
> be truncated in order to have any guarantee. If we can do that we might as
> well force both values to be truncated, right. I think that so far
> in this discussion is has been assumed that the bounds are truncated.

Forcing truncation may have a bad effect on performance.
That will be unacceptable to some users.

--Johan RÃ¥de

Boost list run by bdawes at, gregod at, cpdaniel at, john at