Namespaces
Variants

std:: feclearexcept

From cppreference.net
C++
Numerics library
Floating-point environment
Functions
feclearexcept
(C++11)
(C++11)
(C++11)
(C++11) (C++11)
(C++11) (C++11)
(C++11) (C++11)
(C++11)
(C++11)
Macro constants
(C++11) (C++11) (C++11) (C++11) (C++11) (C++11)
(C++11) (C++11) (C++11) (C++11)
(C++11)
定义于头文件 <cfenv>
int feclearexcept ( int excepts ) ;
(C++11 起)

尝试清除位掩码参数 excepts 中列出的浮点异常，该参数是 浮点异常宏 的按位或组合。

目录

参数

excepts - 列出要清除的异常标志的位掩码

返回值

​ 0 ​ 如果所有指定异常均被成功清除，或当 excepts 为零时。发生错误时返回非零值。

示例

运行此代码 
#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";
}

可能的输出： 

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

参见

(C++11)
检测指定的浮点状态标志是否被设置
(函数)
C 文档 for feclearexcept