Defined in header <fenv.h> | ||
---|---|---|
int feraiseexcept( int excepts ); | (since C99) |
Attempts to raise all floating point exceptions listed in excepts
(a bitwise OR of the floating point exception macros). If one of the exceptions is FE_OVERFLOW
or FE_UNDERFLOW
, this function may additionally raise FE_INEXACT
. The order in which the exceptions are raised is unspecified, except that FE_OVERFLOW
and FE_UNDERFLOW
are always raised before FE_INEXACT
.
excepts | - | bitmask listing the exception flags to raise |
0
if all listed exceptions were raised, non-zero value otherwise.
#include <stdio.h> #include <fenv.h> #pragma STDC FENV_ACCESS ON void show_fe_exceptions(void) { printf("current exceptions raised: "); if(fetestexcept(FE_DIVBYZERO)) printf(" FE_DIVBYZERO"); if(fetestexcept(FE_INEXACT)) printf(" FE_INEXACT"); if(fetestexcept(FE_INVALID)) printf(" FE_INVALID"); if(fetestexcept(FE_OVERFLOW)) printf(" FE_OVERFLOW"); if(fetestexcept(FE_UNDERFLOW)) printf(" FE_UNDERFLOW"); if(fetestexcept(FE_ALL_EXCEPT)==0) printf(" none"); feclearexcept(FE_ALL_EXCEPT); printf("\n"); } double some_computation(void) { /* Computation reaches a state that causes overflow. */ int r = feraiseexcept(FE_OVERFLOW | FE_INEXACT); printf("feraiseexcept() %s\n", (r?"fails":"succeeds")); return 0.0; } int main(void) { some_computation(); show_fe_exceptions(); return 0; }
Output:
feraiseexcept() succeeds current exceptions raised: FE_INEXACT FE_OVERFLOW
(C99) | clears the specified floating-point status flags (function) |
(C99) | determines which of the specified floating-point status flags are set (function) |
C++ documentation for feraiseexcept |
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