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× C++ Standard Library C++ STL Library


The FE_OVERFLOW macro expands to a value of type integer constant expression that is distinct powers of 2, which uniquely identifies the floating-point exception raised on overflow range errors.

Overflow range errors occur when the result of an operation cannot be represented as a value of its return type because its magnitude is too large (either positive or negative). Operations that overflow while the default rounding mode is in effect, return a positive or a negative HUGE_VAL (or HUGE_VALF or HUGE_VALL).

Definition in the <cfenv> header file is:

#define FE_OVERFLOW  /*implementation defined power of 2*/                

MacrosDescription
FE_DIVBYZERO Pole error exception occurred in an earlier floating-point operation.
FE_INEXACT Inexact result exception occurred in an earlier floating-point operation (rounding was necessary to store the result).
FE_INVALID Invalid argument exception occurred (domain error occurred) in an earlier floating-point operation.
FE_OVERFLOW Overflow range error exception occurred in an earlier floating-point operation (result was too large to be representable).
FE_UNDERFLOW Underflow range error exception occurred in an earlier floating-point operation (result was subnormal with a loss of precision).
FE_ALL_EXCEPT Bitwise OR of all supported floating-point exceptions.

Certain library implementations may define additional macro constants in <cfenv> to identify additional floating-point exceptions (with their corresponding macros also beginning with FE_).

See math_errhandling for more details.

Example:

The below example shows the usage of FE_OVERFLOW macro.

#include <iostream>
#include <cfenv>
#include <cfloat>

using namespace std;
 
int main (){
  cout<<"DBL_MAX*2 = "<<(DBL_MAX*2)<<"\n";
  if(fetestexcept(FE_OVERFLOW))
    cout<<"Domain error is reported.\n";
  else
    cout<<"Domain error is not reported.\n";

  return 0;
}

The output of the above code will be:

DBL_MAX*2 = inf
Domain error is reported.

❮ C++ <cfenv> Library