NAME

fetestexcept — test floating-point exception flags

SYNOPSIS

#include <fenv.h>

int fetestexcept(int excepts);

DESCRIPTION

[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.

The fetestexcept () function shall determine which of a specified subset of the floating-point exception flags are currently set. The excepts argument specifies the floating-point status flags to be queried.

RETURN VALUE

The fetestexcept () function shall return the value of the bitwise-inclusive OR of the floating-point exception macros corresponding to the currently set floating-point exceptions included in excepts.

ERRORS

No errors are defined.

The following sections are informative.

EXAMPLES

The following example calls function f () if an invalid exception is set, and then function g () if an overflow exception is set:

#include <fenv.h>
/* ... */
{
    #pragma STDC FENV_ACCESS ON
    int set_excepts;
    feclearexcept(FE_INVALID | FE_OVERFLOW);
    // maybe raise exceptions
    set_excepts = fetestexcept(FE_INVALID | FE_OVERFLOW);
    if (set_excepts & FE_INVALID) f();
    if (set_excepts & FE_OVERFLOW) g();
    /* ... */
}

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

feclearexcept(3), fegetexceptflag(3), feraiseexcept(3)

XBD <fenv.h>

CHANGE HISTORY

First released in Issue 6. Derived from the ISO/IEC 9899:1999 (“ISO C99”) standard.

End of informative text.