Question

I have a set of functions and need to convert potentially thrown exceptions into
error codes.

To this end I have wrapped the actual calls with try/catch statements:

int f_with_error_codes()
{
  try {
    f(); // wrapped function call

    return E_SUCCESS;
  }
  catch (error1&) {
    return E_ERROR1;
  }
  catch (error2&) {
    return E_ERROR2;
  }
}

int g_with_error_codes(int a);
{
  try {
    G g(a);        // wrapped expressions
    g.print();

    return E_SUCCESS;
  }
  catch (error1&) {
    return E_ERROR1;
  }
  catch (error2&) {
    return E_ERROR2;
  }
}

...

These catch statmements repeat themselves. Additionally whenever a new exception
is added a new catch clause has to be added to every call wrapper.

Is a macro like below for replacing the catch statements appropriate?

#define CATCH_ALL_EXCEPTIONS  \
catch (error1&) {             \
  return E_ERROR1;            \
}                             \
catch (error2&) {             \
  return E_ERROR2;            \
}

Which would results in:

int f_with_error_codes()
{
  try {
    f(); // the wrapped

    return E_SUCCESS;
  }
  CATCH_ALL_EXCEPTIONS

Answer 1

You can use a function instead of a macro like this:

int f_with_error_codes() 
{ 
  try { 
    f(); // wrapped function call 

    return E_SUCCESS; 
  } 
  catch (...) { 
    return error_code();
  } 
}

int error_code()
{
  try { 
    throw;
  } 
  catch (error1&) { 
    return E_ERROR1; 
  } 
  catch (error2&) { 
    return E_ERROR2; 
  } 
}