std::feclearexcept
来自 cppreference.cn
| 定义于头文件 <cfenv> |
||
| int feclearexcept( int excepts ); |
(始于 C++11) | |
尝试清除位掩码参数 excepts 中列出的浮点异常，它是 浮点异常宏 的按位或。
目录 |
[edit] 参数
| excepts | - | 位掩码，列出要清除的异常标志 |
[edit] 返回值
0 如果所有指示的异常都成功清除，或者 excepts 为零，则返回 0。 错误时返回非零值。
[edit] 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
[edit] 参见
| (C++11) |
确定设置了哪些指定的浮点状态标志 (函数) |
| C 文档 关于 feclearexcept
| |
