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