The fetestexcept() function is defined in <cfenv> header file.
fetestexcept() prototype
int fetestexcept( int excepts );
The fetestexcept() function tests whether the floating point exception specified by excepts are currently set. The argument excepts is a bitwise OR of the floating point exception macros.
fetestexcept() Parameters
- excepts: Bitmask listing the exception flags to test.
fetestexcept() Return value
- Bitwise OR of the floating-point exception macros that are both included in excepts and correspond to floating-point exceptions currently set.
Example: How fetestexcept() function works?
#include <iostream>
#include <cmath>
#include <cfenv>
#pragma STDC FENV_ACCESS ON
using namespace std;
void print_exceptions()
{
cout << "Raised exceptions: ";
if(fetestexcept(FE_ALL_EXCEPT))
{
if(fetestexcept(FE_DIVBYZERO))
cout << "FE_DIVBYZERO ";
if(fetestexcept(FE_INEXACT))
cout << "FE_INEXACT ";
if(fetestexcept(FE_INVALID))
cout << "FE_INVALID ";
if(fetestexcept(FE_OVERFLOW))
cout << "FE_OVERFLOW ";
if(fetestexcept(FE_UNDERFLOW))
cout << "FE_UNDERFLOW ";
}
else
cout << "None";
cout << endl;
}
int main(void)
{
print_exceptions();
feraiseexcept(FE_INVALID|FE_DIVBYZERO);
print_exceptions();
feclearexcept(FE_ALL_EXCEPT);
print_exceptions();
return 0;
}
When you run the program, the output will be:
Raised exceptions: None Raised exceptions: FE_DIVBYZERO FE_INVALID Raised exceptions: None