Re[2]: Directors and passing args by value.

Hello Mark,

MR> Ok.  I had to change the (python) director method generator slightly
MR> to handle enum returns, and I want to run some tests before checking
MR> in the new code.  Good motivation to finally write that typemap 
MR> regression test I guess.

I tried to create typemap by myself:
     
%typemap(directorout) enum SWIGTYPE
   "$result = ($1_type) PyInt_AsLong($input);"

This produces code like this:

E SwigDirector_C::method() {
    int c_result ;
    PyObject *result;
    
    if (swig_get_up()) {
        return C::method();
    }
    result = PyObject_CallMethod(swig_get_self(), "method", NULL);
    c_result = (E) PyInt_AsLong(result);
    Py_XDECREF(result);
    return c_result;
}

That doesn't compile:
... : error C2440: 'return' : cannot convert from 'int' to 'E'
        Conversion to enumeration type requires an explicit cast
        (static_cast, C-style cast or function-style cast)

Could you tell me what your solution is?
   
Best regards,
 Kerim                            mailto:warkid@xxxxxxxxx

Tuesday, November 18, 2003, 7:44:44 PM, you wrote:

MR> Cheers,
MR> Mark


MR> On Tue, Nov 18, 2003 at 05:10:43PM +0300, Kerim Borchaev wrote:
>>   I'm sorry - I've mistaken. Passing enum to function is ok.
>>   Returning - this is what doesn't work.
>> 
>> Best regards,
>>  Kerim                            mailto:warkid@xxxxxxxxx
>> 
>> Tuesday, November 18, 2003, 3:46:36 PM, you wrote:
>> 
>> KB> Hello.
>> 
>> KB>      I've uncommented that "dangerous" typemap;-) It works well except
>> KB>      it doesn't work with enums.
>> KB>      What could I do to make it handle them?
>> 
>> KB> Thanks.
>> KB>  Kerim                            mailto:warkid@xxxxxxxxx
>> 
>> KB> Tuesday, November 18, 2003, 10:28:21 AM, you wrote:
>> 
>> MR>> I actually added the typemap to do this to python.swg many
>> MR>> months ago, but commented it out with the note "this is rather
>> MR>> dangerous." ;-)  I probably should have been more explicit at
>> MR>> that time, since I can't remember now exactly what concerned 
>> MR>> me about it (other than the possibility of the python method 
>> MR>> hanging on to references to its arguments).  Maybe there's 
>> MR>> nothing terribly wrong with that typemap as it stands, or 
>> MR>> maybe there's another approach that would be safer.  Any 
>> MR>> typemap/object ownership gurus care to comment?
>> 
>> MR>> Mark
>> 
>> 
>> MR>> On Mon, Nov 17, 2003 at 12:08:20PM +0300, Kerim Borchaev wrote:
>> >>> Hello.
>> >>> 
>> >>>    I've checked CVS version and now it seems that directors aren't
>> >>>    generated for methods with args passed by value. Any plans to
>> >>>    support it?
>> >>> 
>> >>> Best regards,
>> >>>  Kerim                            mailto:warkid@xxxxxxxxx
>> >>> 
>> >>> Thursday, November 13, 2003, 8:16:02 PM, you wrote:
>> >>> 
>> >>> MR> Hi Kerim,
>> >>> 
>> >>> MR> What version of SWIG are you using?   SWIG cvs parses your
>> >>> MR> interface without any warnings on my machine, and does the
>> >>> MR> right thing in the python test.   Note that if you ever get 
>> >>> MR> warning 461, SWIG will not generate any director stubs for 
>> >>> MR> the method.  So the result you get in your Python test is 
>> >>> MR> understandable, and the only question is what is causing the
>> >>> MR> warning.  
>> >>> 
>> >>> MR> Cheers,
>> >>> MR> Mark
>> >>> 
>> >>> 
>> >>> MR> On Thu, Nov 13, 2003 at 05:55:55PM +0300, Kerim Borchaev wrote:
>> >>> >> Hello swig,
>> >>> >> 
>> >>> >>   SWIG doesn't wrap for directors methods that return objects by
>> >>> >>   value?
>> >>> >> 
>> >>> >> This code:
>> >>> >> //main.i
>> >>> >> %module(directors="1") test
>> >>> >> 
>> >>> >> %feature("director");
>> >>> >> %inline %{
>> >>> >> struct D{
>> >>> >>     int value;
>> >>> >>     };
>> >>> >>     
>> >>> >> struct C{
>> >>> >>     virtual ~C(){}
>> >>> >>     virtual D method(){
>> >>> >>         D d;
>> >>> >>         d.value = 7;
>> >>> >>         return d;
>> >>> >>         }
>> >>> >>     };
>> >>> >>     
>> >>> >> int getValue(C&o){
>> >>> >>     D d = o.method();
>> >>> >>     return d.value;
>> >>> >>     }
>> >>> >> %}
>> >>> >> //////////////////////////
>> >>> >> 
>> >>> >> Produces this warning:
>> >>> >> 
>> >>> >> main.i:29: Warning(461): Unable to return type D in director method 
>> >>> >> C::method (s
>> >>> >> kipping method).
>> >>> >> 
>> >>> >> And works like this:
>> >>> >> 
>> >>> >> Python 2.3.2 (#49, Oct  2 2003, 20:02:00) [MSC v.1200 32 bit (Intel)] 
>> >>> >> on win32
>> >>> >> Type "help", "copyright", "credits" or "license" for more information.
>> >>> >> >>> import test
>> >>> >> >>> from test import *
>> >>> >> >>> class Derived(C):
>> >>> >> ...     def method(self):
>> >>> >> ...             d = D()
>> >>> >> ...             d.value = 13
>> >>> >> ...             return d
>> >>> >> ...
>> >>> >> >>> getValue(Derived())#should return 13
>> >>> >> 7
>> >>> >> 
>> >>> >> 
>> >>> >> 
>> >>> >> Best regards,
>> >>> >>  Kerim                          mailto:warkid@xxxxxxxxx
>> >>> >> 
>> >>> >> 
>> >>> >> _______________________________________________
>> >>> >> Swig maillist  -  Swig@xxxxxxxxxxxxxxx
>> >>> >> http://mailman.cs.uchicago.edu/mailman/listinfo/swig
>> >>> 
>> >>> 
>> 
>> 
>> KB> _______________________________________________
>> KB> Swig maillist  -  Swig@xxxxxxxxxxxxxxx
>> KB> http://mailman.cs.uchicago.edu/mailman/listinfo/swig
>> 
>> 
>> _______________________________________________
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>> http://mailman.cs.uchicago.edu/mailman/listinfo/swig


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