7.6.4.3 The fesetenv function
Synopsis
#include <fenv.h>
int fesetenv(const fenv_t *envp);
Description
The fesetenv function attempts to establish the floating-point environment represented by the object pointed to by envp. The argument envp shall point to an object set by a call to fegetenv or feholdexcept, or equal a floating-point environment macro. Note that fesetenv merely installs the state of the floating-point status flags represented through its argument, and does not raise these floating-point exceptions.
Returns
The fesetenv function returns zero if the environment was successfully established. Otherwise, it returns a nonzero value.