Tests the status flags in the floating-point environment against a bit mask
#include <fenv.h> int fetestexcept ( int excepts );
The fetestexcept( ) function takes as its argument a bitwise OR of the values of macros defined in fenv.h to represent the floating-point exception flags. The macros are listed under feraiseexcept( ) in this chapter.
fetestexcept( ) returns the bitwise AND of the values representing the exception flags that were set in the argument and the exception flags that are currently set in the floating-point environment.