trusty (3) fegetround.3posix.gz

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NAME
       fegetround, fesetround - get and set current rounding direction


SYNOPSIS
       #include <fenv.h>

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


DESCRIPTION
       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 IEEE Std 1003.1-2001, <fenv.h>


       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 .