std::feraiseexcept

From cppreference.com
< cpp‎ | numeric‎ | fenv
 
 
 
Floating-point environment
Functions
feraiseexcept
(C++11)
(C++11)(C++11)
(C++11)(C++11)
Macro constants
(C++11)
 
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

#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";
}

Output:

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

See also

clears the specified floating-point status flags
(function)
determines which of the specified floating-point status flags are set
(function)