std::feclearexcept - cppreference.com

##### cppreference.com

##### Search

Create account

##### Namespaces

- Page
- Discussion

##### Variants

##### Views

- View
- Edit
- History

##### Actions

# std::feclearexcept

From cppreference.com
< cpp‎ | numeric‎ | fenv

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.

### [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

[edit]
Run this code

    #include <iostream>
    #include <cfenv>
    #include <cmath>

    #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 << "divsion 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";
        }
    }

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

fetestexcept (C++11) | determines which of the specified floating-point status flags are set (function) [edit]

Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/numeric/fenv/feclearexcept&oldid=62812"