NAME

       lrint, lrintf, lrintl - round to nearest integer value using current rounding direction

SYNOPSIS

       #include <math.h>

       long lrint(double x);
       long lrintf(float x);
       long lrintl(long double x);

DESCRIPTION

       These  functions  shall  round  their  argument  to  the  nearest  integer value, rounding
       according to the current rounding direction.

       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 rounded integer value.

       If x is NaN, a domain error shall occur and an unspecified value is returned.

       If x is +Inf, a domain error shall occur and an unspecified value is returned.

       If x is -Inf, a domain error shall occur and an unspecified value is returned.

       If  the  correct  value  is  positive and too large to represent as a long, a domain error
       shall occur and an unspecified value is returned.

       If the correct value is negative and too large to represent as  a  long,  a  domain  error
       shall occur and an unspecified value is returned.

ERRORS

       These functions shall fail if:

       Domain Error
              The  x  argument  is  NaN  or ±Inf, or the correct value is not representable as an
              integer.

       If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be
       set  to [EDOM]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero,
       then the invalid 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

       These  functions  provide  floating-to-integer  conversions.  They  round according to the
       current rounding direction. If the rounded value is outside the range of the return  type,
       the numeric result is unspecified and the invalid floating-point exception is raised. When
       they raise no other floating-point exception and the result  differs  from  the  argument,
       they raise the inexact floating-point exception.

FUTURE DIRECTIONS

       None.

SEE ALSO

       feclearexcept()   ,   fetestexcept()   ,   llrint()  ,  the  Base  Definitions  volume  of
       IEEE Std 1003.1-2001,  Section  4.18,  Treatment  of  Error  Conditions  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
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .