Re: 3.0.1 release?

[Michael Goffioul]

On Wed, Apr 9, 2008 at 1:51 AM, John W. Eaton <address@hidden> wrote:
>  I suppose we could write something like
>
>   double ip;
>   return modf (x, &ip) == 0.0 ? x : (x > 0 ? floor (x + 0.5) : ceil (x - 
> 0.5));
>
>  Is there a better (and still portable) way to determine whether a
>  double value is an integer?

The following code seems to work fine:

  if (x >= 0)
    {
      double y = floor (x);

      if ((x - y) >= 0.5)
        y += 1.0;

      return y;
    }
  else
    {
      double y = ceil (x);

      if ((y - x) >= 0.5)
        y -= 1.0;

      return y;
    }

This is taken from gnulib:round.c (I guess it's no problem to grab
some code from
GPL project to put it into another GPL project). Running the test suite does not
seem to return new problems.

Michael.