C++: error: exception handling disabled, use -fexceptions to enable

Question

I am trying to compile simple code with -fno-exceptions flag. Its giving error.

Please let me know how to suppress this. I am using gcc version 4.6.3

Code

#include <iostream>
using namespace std;
int main () {
  try
  {
    throw 20;
  }
  catch (int e)
  {
    cout << "An exception occurred. Exception Nr. " << e << '\n';
  }
  return 0;
}

Log

> g++ throw.cc -o out -fno-exceptions
throw.cc: In function ‘int main()’:
throw.cc:10:11: error: exception handling disabled, use -fexceptions to enable
throw.cc:14:56: error: ‘e’ was not declared in this scope

Edit

I have a client code which have lot throws like this. I have to integrate this in my project and I can't control compilation flags to build(which will come from config which has -fno-exceptions enabled). I wanted a quick work around that I can suggest.

EDIT

I found a workaround see below for my answer.

Answer 1

You cannot use -fno-exceptions flag with program, that use exceptions (try/catch/throw).

Quote from gcc manual

Before detailing the library support for -fno-exceptions, first a passing note on the things lost when this flag is used: it will break exceptions trying to pass through code compiled with -fno-exceptions whether or not that code has any try or catch constructs. If you might have some code that throws, you shouldn't use -fno-exceptions. If you have some code that uses try or catch, you shouldn't use -fno-exceptions.

Answer 2

I found a workaround. Except for the "e" in the catch block the code can be rewritten like

#include <iostream>
using namespace std;
int main () {
  __try
  {
    __throw_exception_again 20;
  }
  __catch (int e)
  {
    cout << "An exception occurred." << '\n';
  }
  return 0;
}

and can be compiled with

g++ throw.cc -o out -fno-exceptions.