centos man page for feupdateenv

FEUPDATEENV(3P) 					     POSIX Programmer's Manual						   FEUPDATEENV(3P)

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

NAME
       feupdateenv - update floating-point environment

SYNOPSIS
       #include <fenv.h>

       int feupdateenv(const fenv_t *envp);

DESCRIPTION
       The feupdateenv() function shall attempt to save the currently raised floating-point  exceptions  in  its  automatic  storage,  attempt	to
       install	the  floating-point  environment  represented by the object pointed to by envp, and then attempt to raise the saved floating-point
       exceptions. The argument envp shall point to an object set by a call to feholdexcept() or fegetenv(), or equal a floating-point environment
       macro.

RETURN VALUE
       The feupdateenv() function shall return a zero value if and only if all the required actions were successfully carried out.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       The following example shows sample code to hide spurious underflow floating-point exceptions:

	      #include <fenv.h>
	      double f(double x)
	      {
		  #pragma STDC FENV_ACCESS ON
		  double result;
		  fenv_t save_env;
		  feholdexcept(&save_env);
		  // compute result
		  if (/* test spurious underflow */)
		  feclearexcept(FE_UNDERFLOW);
		  feupdateenv(&save_env);
		  return result;
	      }

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       fegetenv(), feholdexcept(), the Base Definitions volume of IEEE Std 1003.1-2001, <fenv.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- 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 .

IEEE
/The Open Group						       2003							   FEUPDATEENV(3P)