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

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This header was originally in the C standard library as <fenv.h>.

This header is part of the floating-point environment library.

Contents

[edit] Types

fenv_t The type representing the entire floating-point environment
fexcept_t The type representing all floating-point status flags collectively

[edit] Functions

clears the specified floating-point status flags
(function) [edit]
determines which of the specified floating-point status flags are set
(function) [edit]
raises the specified floating-point exceptions
(function) [edit]
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]
saves or restores the current floating-point environment
(function) [edit]
saves the environment, clears all status flags and ignores all future errors
(function) [edit]
restores the floating-point environment and raises the previously raised exceptions
(function) [edit]

[edit] Macros

floating-point exceptions
(macro constant) [edit]
floating-point rounding direction
(macro constant) [edit]
default floating-point environment
(macro constant) [edit]

[edit] Synopsis

namespace std {
    // types
    typedef /* object type */ fenv_t;
    typedef /* object type */ fexcept_t;
 
    // functions
    int 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);
}

[edit] 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