Floating point environment
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浮点环境的浮点状态标志的设置和控制方式实现支持。它是本地线程，每个线程都会继承父线程的初始状态，其浮点环境。浮点运算修改浮点状态标志，用于指示异常结果或辅助信息。浮点控制模式的状态会影响一些浮点运算的结果.
Original:
The floating-point environment is the set of floating-point status flags and control modes supported by the implementation. It is thread-local, each thread inherits the initial state of its floating-point environment from the parent thread. Floating-point operations modify the floating-point status flags to indicate abnormal results or auxiliary information. The state of floating-point control modes affects the outcomes of some floating-point operations.
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浮点环境访问和修改是唯一有意义的
#pragma STDC FENV_ACCESS设置为
ON。否则，执行是免费的假设，浮点控制模式始终是默认的，浮点状态标志从来没有测试或修改。在实践中，一些现有的编译器支持#pragma明确，但大多数编译器允许反正有意义的访问浮点环境.Original:
The floating-point environment access and modification is only meaningful when
#pragma STDC FENV_ACCESS is set to
ON. Otherwise the implementation is free to assume that floating-point control modes are always the default ones and that floating-point status flags are never tested or modified. In practice, few current compilers support the #pragma explicitly, but most compilers allow meaningful access to the floating-point environment anyway.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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[编辑] 类型
| Defined in header
<fenv.h> | |
| fenv_t | 类型代表整个浮点环境
Original: The type representing the entire floating-point environment The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| fexcept_t | 该型集体所有的浮点状态标志
Original: The type representing all floating-point status flags collectively The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[编辑] 功能
| （C99） |
清除指定的浮点状态标志 Original: clears the specified floating-point status flags The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） |
确定哪些指定浮点状态标志被设置 Original: determines which of the specified floating-point status flags are set The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） |
提出了指定的浮点异常 Original: raises the specified floating-point exceptions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） （C99） |
复制或浮点环境指定的浮点状态标志的状态 Original: copies the state of the specified floating-point status flags from or to the floating-point environment The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） （C99） |
获取或设置舍入的方向 Original: gets or sets rounding direction The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） |
保存或恢复当前浮点环境 Original: saves or restores the current floating point environment The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） |
保存环境，清除所有状态标志，而忽略了未来所有的错误 Original: saves the environment, clears all status flags and ignores all future errors The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
| （C99） |
浮点环境恢复和提高了先前抛出异常 Original: restores the floating-point environment and raises the previously raise exceptions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数） |
[编辑] 宏
| 浮点异常 Original: floating-point exceptions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （宏不变） | |
| 浮点舍入方向 Original: floating-point rounding direction The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （宏不变） | |
| （C99） |
默认的浮点环境 Original: default floating-point environment The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （宏不变） |
| 本节是不完整的 原因: FENV_ACCESS |
