Difference between revisions of "cpp/numeric/fenv/feraiseexcept"

Revision as of 20:19, 19 April 2012

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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 <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";
 
}

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

See also