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RINT(P) 			    POSIX Programmer's Manual				  RINT(P)

NAME
       rint, rintf, rintl - round-to-nearest integral value

SYNOPSIS
       #include <math.h>

       double rint(double x);
       float rintf(float x);
       long double rintl(long double x);

DESCRIPTION
       These functions shall return the integral value (represented as a double) nearest x in the
       direction of the current rounding mode.	The  current  rounding	mode  is  implementation-
       defined.

       If the current rounding mode rounds toward negative infinity, then rint() shall be equiva-
       lent to floor() . If the current rounding  mode	rounds	toward	positive  infinity,  then
       rint() shall be equivalent to ceil() .

       These functions differ from the nearbyint(), nearbyintf(), and nearbyintl() functions only
       in that they may raise the inexact floating-point exception if the result differs in value
       from the argument.

       An  application	wishing  to  check for error situations should set errno to zero and call
       feclearexcept(FE_ALL_EXCEPT) before calling these functions.  On return, if errno is  non-
       zero  or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero,
       an error has occurred.

RETURN VALUE
       Upon successful completion, these functions shall return the  integer  (represented  as	a
       double precision number) nearest x in the direction of the current rounding mode.

       If x is NaN, a NaN shall be returned.

       If x is +-0 or +-Inf, x shall be returned.

       If  the correct value would cause overflow, a range error shall occur and rint(), rintf(),
       and rintl() shall return the value of the macro +-HUGE_VAL, +-HUGE_VALF,  and  +-HUGE_VALL
       (with the same sign as x), respectively.

ERRORS
       These functions shall fail if:

       Range Error
	      The result would cause an overflow.

       If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be
       set to [ERANGE]. If the integer expression (math_errhandling  &	MATH_ERREXCEPT)  is  non-
       zero, then the overflow floating-point exception shall be raised.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       On  error,  the	expressions  (math_errhandling	&  MATH_ERRNO)	and  (math_errhandling	&
       MATH_ERREXCEPT) are independent of each other, but at least one of them must be non-zero.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       abs() , ceil() , feclearexcept() , fetestexcept() , floor() , isnan() , nearbyint() ,  the
       Base  Definitions  volume of IEEE Std 1003.1-2001, Section 4.18, Treatment of Error Condi-
       tions for Mathematical Functions, <math.h>

COPYRIGHT
       Portions of this text are reprinted and	reproduced  in	electronic  form  from	IEEE  Std
       1003.1,	2003  Edition,	Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard, the original IEEE and The Open Group Standard is the referee document. The orig-
       inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group			       2003					  RINT(P)
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