Sets the specified floating-point status flags in the current floating-point environment.


int fesetexceptflag(
     const fexcept_t *pstatus,
     int excepts


Pointer to an fexcept_t object containing the values to set the exception status flags to. The object may be set by a previous call to fegetexceptflag.

The floating-point exception status flags to set.

Return Value

If all the specified exception status flags are set successfully, returns 0. Otherwise, returns a nonzero value.


The fesetexceptflag function sets the state of the floating-point exception status flags specified by excepts to the corresponding values set in the fexcept_t object pointed to by pstatus. It does not raise the exceptions. The pstatus pointer must point to a valid fexcept_t object, or subsequent behavior is undefined. The fesetexceptflag function supports these exception macro values in excepts, defined in <fenv.h>:

Exception Macro Description
FE_DIVBYZERO A singularity or pole error occurred in an earlier floating-point operation; an infinity value was created.
FE_INEXACT The function was forced to round the stored result of an earlier floating-point operation.
FE_INVALID A domain error occurred in an earlier floating-point operation.
FE_OVERFLOW A range error occurred; an earlier floating-point operation result was too large to be represented.
FE_UNDERFLOW An earlier floating-point operation result was too small to be represented at full precision; a denormal value was created.
FE_ALLEXCEPT The bitwise OR of all supported floating-point exceptions.

The excepts argument may be zero, one of the supported floating-point exception macros, or the bitwise OR of two or more of the macros. The effect of any other argument value is undefined.

To use this function, you must turn off floating-point optimizations that could prevent access by using the #pragma fenv_access(on) directive prior to the call. For more information, see fenv_access.


Function C header C++ header
fesetexceptflag <fenv.h> <cfenv>

For additional compatibility information, see Compatibility.

See also

Alphabetical Function Reference