AW: [C++-sig] Virtual functions with default implementation.

Gottfried.Ganssauge at HAUFE.DE Gottfried.Ganssauge at HAUFE.DE
Tue Dec 17 17:29:48 CET 2002 

At least it's not the compiler: the same thing happens on MSVC6.

Cheers,

G.Gan?auge

> -----Ursprungliche Nachricht-----
> Von: Jacek Generowicz [mailto:jacek.generowicz at cern.ch]
> Gesendet: Dienstag, 17. Dezember 2002 16:39
> An: c++-sig at python.org
> Betreff: [C++-sig] Virtual functions with default implementation.
> 
> 
> By copying and pasting the example code from
> 
> http://www.boost.org/libs/python/doc/tutorial/doc/class_virtua
> l_functions.html
> 
> I constucted the following test program.
> 
> ======================================================================
> #include <boost/python.hpp>
> 
> using namespace boost::python;
> 
> struct Base
> {
>   virtual int f() { return 0; }
>   virtual ~Base();
> };
> 
> struct BaseWrap : Base
> {
>   BaseWrap(PyObject* self_)
>     : self(self_) {}
>   int f() { return call_method<int>(self, "f"); }
>   static int default_f(Base* b) { return b->Base::f(); } // 
> <<=== added
>         PyObject* self;
> };
> 
> BOOST_PYTHON_MODULE(virt)
> {
>   class_<Base, BaseWrap>("Base")
>     .def("f", &BaseWrap::default_f)
>     ;
> }
> ======================================================================
> 
> This fails to compile (errors included below for completenes) with gcc
> 3.2 (and Boost 1.29).
> 
> Is it me, is it the docs, or something else ?
> 
> Thanks,
> 
> Jacek.
> 
> 
> 
> Tons of compiler output follows ...
> 
> 
> 
> In file included from 
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon.hpp:43,
>                  from virtualboost.cc:1:
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:184:42: warning: pasting "operator" and "+" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:185:42: warning: pasting "operator" and "-" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:186:42: warning: pasting "operator" and "*" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:187:42: warning: pasting "operator" and "/" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:188:42: warning: pasting "operator" and "%" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:189:49: warning: pasting "operator" and 
> "<<" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:190:49: warning: pasting "operator" and 
> ">>" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:191:42: warning: pasting "operator" and "&" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:192:42: warning: pasting "operator" and "^" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:193:40: warning: pasting "operator" and "|" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:194:39: warning: pasting "operator" and ">" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:195:40: warning: pasting "operator" and 
> ">=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:196:39: warning: pasting "operator" and "<" 
> does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:197:40: warning: pasting "operator" and 
> "<=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:198:40: warning: pasting "operator" and 
> "==" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:199:40: warning: pasting "operator" and 
> "!=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:271:38: warning: pasting "operator" and 
> "+=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:272:38: warning: pasting "operator" and 
> "-=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:273:38: warning: pasting "operator" and 
> "*=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:274:38: warning: pasting "operator" and 
> "/=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:275:38: warning: pasting "operator" and 
> "%=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:276:42: warning: pasting "operator" and 
> "<<=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:277:42: warning: pasting "operator" and 
> ">>=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:278:38: warning: pasting "operator" and 
> "&=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:279:38: warning: pasting "operator" and 
> "^=" does not give a valid preprocessing token
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/operators.hpp:280:37: warning: pasting "operator" and 
> "|=" does not give a valid preprocessing token
> In file included from virtualboost.cc:1:
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon.hpp:62:8: warning: extra tokens at end of #endif directive
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/object/value_holder.hpp: In
>    constructor 
> `boost::python::objects::value_holder_back_reference<Held, 
>    BackReferenceType>::value_holder_back_reference(PyObject*, 
> A0) [with A0 = 
>    boost::reference_wrapper<const Base>, Held = Base, 
> BackReferenceType = 
>    BaseWrap]':
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/object/make_instance.hpp:65:   instantiated from `static Holder* >
boost::python::objects::make_instance<T, 
> Holder>::construct(boost::python::objects::instance<Holder>*, 
> boost::reference_wrapper<const T>) [with T = Base, Holder = 
> boost::python::objects::value_holder_back_reference<Base, BaseWrap>]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/object/make_instance.hpp:35:   instantiated from `static PyObject* >
boost::python::objects::make_instance<T, 
> Holder>::execute(Arg&) [with Arg = const 
> boost::reference_wrapper<const Base>, T = Base, Holder = 
> boost::python::objects::value_holder_back_reference<Base, BaseWrap>]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/object/class_wrapper.hpp:23:   instantiated from `static PyObject* >
boost::python::objects::class_wrapper<Src, Holder, 
> MakeInstance>::convert(const Src&) [with Src = Base, Holder = 
> boost::python::objects::value_holder_back_reference<Base, 
> BaseWrap>, MakeInstance = 
> boost::python::objects::make_instance<Base, 
> boost::python::objects::value_holder_back_reference<Base, 
> BaseWrap> >]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/converter/to_python_function_type.hpp:24:   instantiated from `static
PyObject* > boost::python::converter::as_to_python_function<T, 
> ToPython>::convert(const void*) [with T = Base, ToPython = 
> boost::python::objects::class_wrapper<Base, 
> boost::python::objects::value_holder_back_reference<Base, 
> BaseWrap>, boost::python::objects::make_instance<Base, 
> boost::python::objects::value_holder_back_reference<Base, 
> BaseWrap> > >]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/to_python_converter.hpp:32:   instantiated from
`boost::python::to_python_converter<T, > Conversion>::to_python_converter()
[with T = Base, Conversion 
> = boost::python::objects::class_wrapper<Base, 
> boost::python::objects::value_holder_back_reference<Base, 
> BaseWrap>, boost::python::objects::make_instance<Base, 
> boost::python::objects::value_holder_back_reference<Base, 
> BaseWrap> > >]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/class.hpp:80:   instantiated from `void 
> boost::python::detail::register_copy_constructor(const 
> boost::mpl::bool_c<true>&, const SelectHolder&, T*) [with T = 
> Base, SelectHolder = 
> boost::python::objects::detail::select_value_holder<Base, BaseWrap>]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/class.hpp:422:   instantiated from `void 
> boost::python::class_<T, X1, X2, X3>::register_() const [with 
> T = Base, X1 = BaseWrap, X2 = 
> boost::python::detail::not_specified, X3 = 
> boost::python::detail::not_specified]'
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
> hon/class.hpp:432:   instantiated from 
> `boost::python::class_<T, X1, X2, X3>::class_(const char*, 
> const char*) [with T = Base, X1 = BaseWrap, X2 = 
> boost::python::detail::not_specified, X3 = 
> boost::python::detail::not_specified]'
> virtualboost.cc:22:   instantiated from here
> /afs/cern.ch/sw/lcg/external/Boost/1.29.0/rh73_gcc32/boost/pyt
hon/object/value_holder.hpp:129: no
>    matching function for call to 
> `BaseWrap::BaseWrap(PyObject*&, const Base&)'
> virtualboost.cc:12: candidates are: BaseWrap::BaseWrap(const 
> BaseWrap&)
> virtualboost.cc:14:                 BaseWrap::BaseWrap(PyObject*)
> 
> 
> 
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