Rounds its argument to an integral value according to the current
    IEEE rounding direction specified by the user.

    This function is supported on OpenVMS Integrity servers and
    Alpha only.

    Format

      #include  <math.h>

      double rint  (double x);

      float rintf  (float x,);

      long double rintl  (long double x);

1 - Argument

 x

    A real number.

2 - Description

    The rint functions return the nearest integral value to x in
    the direction of the current IEEE rounding mode specified on the
    /ROUNDING_MODE command-line qualifier.

    If the current rounding mode rounds toward negative Infinity,
    then rint is identical to floor. If the current rounding mode
    rounds toward positive Infinity, then rint is identical to ceil.

    If |x| = Infinity, rint returns x.

3 - Return Values

    n                  The nearest integral value to x in the
                       direction of the current IEEE rounding mode.
    NaN                x is NaN; errno is set to EDOM.