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std::feclearexcept

From cppreference.com
< cpp‎ | numeric‎ | fenv
 
 
 
Floating-point environment
Functions
feclearexcept
(C++11)
(C++11)(C++11)
(C++11)(C++11)
Macro constants
(C++11)
 
Defined in header <cfenv>
int feclearexcept( int excepts );
(since C++11)

Attempts to clear the floating-point exceptions that are listed in the bitmask argument excepts, which is a bitwise OR of the floating point exception macros.

Contents

[edit] Parameters

excepts - bitmask listing the exception flags to clear

[edit] Return value

0 if all indicated exceptions were successfully cleared or if excepts is zero. Returns a non-zero value on error.

[edit] Example

#include <cfenv>
#include <cmath>
#include <iostream>
 
// #pragma STDC FENV_ACCESS ON
 
volatile double zero = 0.0; // volatile not needed where FENV_ACCESS is supported
volatile double one = 1.0;  // volatile not needed where FENV_ACCESS is supported
 
int main()
{
    std::feclearexcept(FE_ALL_EXCEPT);
    std::cout <<  "1.0/0.0 = " << 1.0 / zero << '\n';
    if (std::fetestexcept(FE_DIVBYZERO))
        std::cout << "division by zero reported\n";
    else
        std::cout << "division by zero not reported\n";
 
    std::feclearexcept(FE_ALL_EXCEPT);
    std::cout << "1.0/10 = " << one / 10 << '\n';
    if (std::fetestexcept(FE_INEXACT))
        std::cout << "inexact result reported\n";
    else
        std::cout << "inexact result not reported\n";
 
    std::feclearexcept(FE_ALL_EXCEPT);
    std::cout << "sqrt(-1) = " << std::sqrt(-1) << '\n';
    if (std::fetestexcept(FE_INVALID))
        std::cout << "invalid result reported\n";
    else
        std::cout << "invalid result not reported\n";
}

Possible output:

1.0/0.0 = inf
division by zero reported
1.0/10 = 0.1
inexact result reported
sqrt(-1) = -nan
invalid result reported

[edit] See also

determines which of the specified floating-point status flags are set
(function) [edit]
C documentation for feclearexcept