std::feclearexcept
来自 cppreference.cn
| 定义于头文件 <cfenv> |
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| int feclearexcept( int excepts ); |
(C++11 起) | |
尝试清除在位掩码参数 excepts 中列出的浮点异常，excepts 是浮点异常宏的按位或。
目录 |
[编辑] 参数
| excepts | - | 列出要清除的异常标志的位掩码 |
[编辑] 返回值
0 如果所有指示的异常都已成功清除，或者如果 excepts 为零。错误时返回非零值。
[编辑] 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
[编辑] 参阅
| (C++11) |
确定哪些指定的浮点状态标志已设置 (函数) |
| C 文档 关于 feclearexcept
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