FERAISEEXCEPT(3)           POSIX Programmer's Manual          FERAISEEXCEPT(3)



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

NAME
       feraiseexcept -- raise floating-point exception

SYNOPSIS
       #include <fenv.h>

       int feraiseexcept(int excepts);

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 feraiseexcept() function shall attempt to raise the supported
       floating-point exceptions represented by the excepts argument. The
       order in which these floating-point exceptions are raised is
       unspecified, except that if the excepts argument represents IEC 60559
       valid coincident floating-point exceptions for atomic operations
       (namely overflow and inexact, or underflow and inexact), then overflow
       or underflow shall be raised before inexact.  Whether the
       feraiseexcept() function additionally raises the inexact floating-point
       exception whenever it raises the overflow or underflow floating-point
       exception is implementation-defined.

RETURN VALUE
       If the argument is zero or if all the specified exceptions were
       successfully raised, feraiseexcept() shall return zero. Otherwise, it
       shall return a non-zero value.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       The effect is intended to be similar to that of floating-point
       exceptions raised by arithmetic operations. Hence, enabled traps for
       floating-point exceptions raised by this function are taken.

RATIONALE
       Raising overflow or underflow is allowed to also raise inexact because
       on some architectures the only practical way to raise an exception is
       to execute an instruction that has the exception as a side-effect. The
       function is not restricted to accept only valid coincident expressions
       for atomic operations, so the function can be used to raise exceptions
       accrued over several operations.

FUTURE DIRECTIONS
       None.

SEE ALSO
       feclearexcept(), fegetexceptflag(), fetestexcept()

       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 .



IEEE/The Open Group                  2017                     FERAISEEXCEPT(3)
