Originální popis anglicky:
feupdateenv - update floating-point environment
Návod, kniha: POSIX Programmer's Manual
#include <fenv.h>
int feupdateenv(const fenv_t *
envp);
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.
The
feupdateenv() function shall return a zero value if and only if all
the required actions were successfully carried out.
No errors are defined.
The following sections are informative.
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;
}
None.
None.
None.
fegetenv() ,
feholdexcept() , 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
.
