Standard library header <cfenv> (C++11)

From cppreference.com

This header was originally in the C standard library as

<fenv.h>

.

This header is part of the

floating-point environment

library.

Types

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]

Functions

feclearexcept

(C++11)

clears the specified floating-point status flags
(function)

[edit]

fetestexcept

(C++11)

determines which of the specified floating-point status flags are set
(function)

[edit]

feraiseexcept

(C++11)

raises the specified floating-point exceptions
(function)

[edit]

fegetexceptflagfesetexceptflag

(C++11)(C++11)

copies the state of the specified floating-point status flags from or to the floating-point environment
(function)

[edit]

fegetroundfesetround

(C++11)(C++11)

gets or sets rounding direction
(function)

[edit]

fegetenvfesetenv

(C++11)

saves or restores the current floating-point environment
(function)

[edit]

feholdexcept

(C++11)

saves the environment, clears all status flags and ignores all future errors
(function)

[edit]

feupdateenv

(C++11)

restores the floating-point environment and raises the previously raised exceptions
(function)

[edit]

Macros

Synopsis

#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 */namespacestd{// typesusingfenv_t=/* object type */;usingfexcept_t=/* object type */;// functionsintfeclearexcept(intexcept);intfegetexceptflag(fexcept_t*pflag,intexcept);intferaiseexcept(intexcept);intfesetexceptflag(constfexcept_t*pflag,intexcept);intfetestexcept(intexcept);intfegetround(void);intfesetround(intmode);intfegetenv(fenv_t*penv);intfeholdexcept(fenv_t*penv);intfesetenv(constfenv_t*penv);intfeupdateenv(constfenv_t*penv);}Defect reports

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