Sets the floating-point environment.
long fesetenv(const fenv_t *f);
f Pointer to the floating-point environment
For the argument of this function, specify the environment stored or saved by the fegetenv or feholdexcept function, or the environment equal to the floating-point environment macro.
Do not use this function when compiler option nofpu is selected. If used, the function returns a nonzero value, which indicates an abnormality.