std:: feraiseexcept

Attempts to raise all floating point exceptions listed in excepts (a bitwise OR of the floating point exception macros ). If one of the exceptions is FE_OVERFLOW or FE_UNDERFLOW , this function may additionally raise FE_INEXACT . The order in which the exceptions are raised is unspecified, except that FE_OVERFLOW and FE_UNDERFLOW are always raised before FE_INEXACT .

Parameters

Return value

​ 0 ​ if all listed exceptions were raised, non-zero value otherwise.

Example

#include <cfenv>
#include <iostream>
 
// #pragma STDC FENV_ACCESS ON
 
int main()
{
    std::feclearexcept(FE_ALL_EXCEPT);
    const int r = std::feraiseexcept(FE_UNDERFLOW | FE_DIVBYZERO);
    std::cout << "Raising divbyzero and underflow simultaneously "
              << (r ? "fails" : "succeeds") << " and results in\n";
 
    const int e = std::fetestexcept(FE_ALL_EXCEPT);
    if (e & FE_DIVBYZERO)
        std::cout << "division by zero\n";
    if (e & FE_INEXACT)
        std::cout << "inexact\n";
    if (e & FE_INVALID)
        std::cout << "invalid\n";
    if (e & FE_UNDERFLOW)
        std::cout << "underflow\n";
    if (e & FE_OVERFLOW)
        std::cout << "overflow\n";
}

Raising divbyzero and underflow simultaneously succeeds and results in
division by zero
underflow

See also