[boost] Re: Seeking Boost round() function

From: Jonathan Turkanis (technews_at_[hidden])
Date: 2004-07-19 12:10:00

"Matt Verona" <mattverona_at_[hidden]> wrote in message
news:004c01c46c5f$76ee7b10$6601a8c0_at_adminmd41gg0jc...
> I was reading the Boost documentation, and couldn't find a function
to round
> floating point numbers (up or down) to the nearest integer.
>
> I have my own implementation of this algorithm as follows:
>
> #include <math.h>
>
> double round(double number)
> {
>         return number < 0.0 ? ceil(number-0.5) : floor(number+0.5);
> }
>
> This round function produces the following output:
>
> round(0.0) = 0
> round(1.49) = 1
> round(1.5) = 2
> round(-1.49) = -1
> round(-1.5) = -2
>
> Does Boost contain a simple rounding function like this?
>
> Thanks in advance,
>

Check out Fernando Cacciola's numeric conversion library in CVS. (See
libs/numeric/conversion/doc)

It contains the definition of a function object type converter
parameterized by a source and target type and several traits and
policy classes, including one called Float2IntRounder. There are four
built in float to int rounding policies: Trunc (default), RoundEven,
Ceil and Floor.

Jonathan