PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       fegetround, fesetround — get and set current rounding direction

SYNOPSIS

       #include <fenv.h>

       int fegetround(void);
       int fesetround(int round);

DESCRIPTION

       The functionality described on this reference page is aligned with the ISO C standard. Any
       conflict between the requirements described here and the ISO C standard is  unintentional.
       This volume of POSIX.1‐2017 defers to the ISO C standard.

       The fegetround() function shall get the current rounding direction.

       The  fesetround()  function  shall  establish  the  rounding  direction represented by its
       argument round.  If the argument is not equal to the value of a rounding direction  macro,
       the rounding direction is not changed.

RETURN VALUE

       The  fegetround()  function  shall  return  the  value  of  the  rounding  direction macro
       representing the current rounding direction or a  negative  value  if  there  is  no  such
       rounding direction macro or the current rounding direction is not determinable.

       The  fesetround() function shall return a zero value if and only if the requested rounding
       direction was established.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       The following example saves, sets, and restores the rounding direction, reporting an error
       and aborting if setting the rounding direction fails:

           #include <fenv.h>
           #include <assert.h>
           void f(int round_dir)
           {
               #pragma STDC FENV_ACCESS ON
               int save_round;
               int setround_ok;
               save_round = fegetround();
               setround_ok = fesetround(round_dir);
               assert(setround_ok == 0);
               /* ... */
               fesetround(save_round);
               /* ... */
           }

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of POSIX.1‐2017, <fenv.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1-2017, Standard for Information Technology -- Portable  Operating  System  Interface
       (POSIX),  The  Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .