[DUG] Dumb Friday Question

[karlreynolds at xtra.co.nz]

>You guys don't consider a constructor a function then?
>
>I think its totally stylistic, if you want to have functions returning 
>objects fine, just make it plain that they do,
>
>IMHO
>
>Neven

The downside to having "creator function"s returning objects is that you
have to duplicate the code in TObject.Create to ensure safety, as Struan
pointed out.

// Regular usage: constructor code guarantees no memory leak possibility

  MyObject := TMyObject.Create;
  try
    ...
  finally
    MyObject.Free;
  end;

Replace TMyObject.Create with a creator function and you have to implement
its safety code again yourself:

// Function returning constructed object requires try/except to be safe

  function CreateMyObject: TMyObject;
  begin
    ...
    Result := TMyObject.Create;
    try
{
Any code you might put in here requires this encompassing try/except block
to prevent a memory leak occurring if an exception occurs
}
    except
      Result.Free;
      raise;
    end; 
  end;


And the same again for any additional levels of nesting. Not great from the
POV of encapsulation.

Cheers,
Carl