This header was originally in the C standard library as<fenv.h>.
This header is part of thefloating-point environment library.
Contents |
fenv_t (C++11) | the type representing the entire floating-point environment (typedef)[edit] |
fexcept_t (C++11) | the type representing all floating-point status flags collectively (typedef)[edit] |
(C++11) | clears the specified floating-point status flags (function)[edit] |
(C++11) | determines which of the specified floating-point status flags are set (function)[edit] |
(C++11) | raises the specified floating-point exceptions (function)[edit] |
(C++11)(C++11) | copies the state of the specified floating-point status flags from or to the floating-point environment (function)[edit] |
(C++11)(C++11) | gets or sets rounding direction (function)[edit] |
(C++11) | saves or restores the current floating-point environment (function)[edit] |
(C++11) | saves the environment, clears all status flags and ignores all future errors (function)[edit] |
(C++11) | restores the floating-point environment and raises the previously raised exceptions (function)[edit] |
| floating-point exceptions (macro constant)[edit] | |
| floating-point rounding direction (macro constant)[edit] | |
(C++11) | default floating-point environment (macro constant)[edit] |
#define FE_ALL_EXCEPT /* see description */#define FE_DIVBYZERO /* see description */ // optional#define FE_INEXACT /* see description */ // optional#define FE_INVALID /* see description */ // optional#define FE_OVERFLOW /* see description */ // optional#define FE_UNDERFLOW /* see description */ // optional #define FE_DOWNWARD /* see description */ // optional#define FE_TONEAREST /* see description */ // optional#define FE_TOWARDZERO /* see description */ // optional#define FE_UPWARD /* see description */ // optional #define FE_DFL_ENV /* see description */ namespace std{// typesusing fenv_t=/* object type */;using fexcept_t=/* object type */; // functionsint feclearexcept(int except);int fegetexceptflag(fexcept_t* pflag,int except);int feraiseexcept(int except);int fesetexceptflag(const fexcept_t* pflag,int except);int fetestexcept(int except);int fegetround(void);int fesetround(int mode);int fegetenv(fenv_t* penv);int feholdexcept(fenv_t* penv);int fesetenv(const fenv_t* penv);int feupdateenv(const fenv_t* penv);}
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3905 | C++11 | std::fexcept_t must be an integer type | it is an object type |
