std::feraiseexcept (3) Linux Manual Page

std::feraiseexcept – std::feraiseexcept

Synopsis

Defined in header <cfenv>
int feraiseexcept( int excepts ); (since C++11)
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

excepts – bitmask listing the exception flags to raise

Return value

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

Example

// Run this code

#include <iostream>

#include <cfenv>

  #pragma STDC FENV_ACCESS ON

int main()

{
    std::feclearexcept(FE_ALL_EXCEPT);
    int r = std::feraiseexcept(FE_UNDERFLOW | FE_DIVBYZERO);
    std::cout << "Raising divbyzero and underflow simultaneously "
              << (r ? "fails" : "succeeds") << " and results in\n";
    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";
    }
}

Output:

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

See also

feclearexcept clears the specified floating-point status flags
              (function)
(C++11)
fetestexcept determines which of the specified floating-point status flags are set
              (function)
(C++11)