Re: [Swig-user] FW: FW: FW: [c++0x branch] enum class forward declarations

[William S F. <ws...@fu...>]

On 04/05/12 21:51, William S Fulton wrote:
> On 01/05/12 21:07, Nathan Ridge wrote:
> >
> > ----------------------------------------
> > > From: zer...@ho...
> > > To: ws...@fu...
> > > Subject: RE: [Swig-user] FW: FW: [c++0x branch] enum class forward
> > declarations
> > > Date: Tue, 1 May 2012 20:07:18 +0000
> > >
> > >
> > >>>>>>>> Fixed now. Previously the base type was limited to a few
> > standard
> > >>>>>>>> primitive types, now it also works with more complex types that
> > >>> resolve
> > >>>>>>>> to an acceptable underlying integral type, eg:
> > >>>>>>>
> > >>>>>>> Thanks! My interface file now passes SWIG without any syntax
> > errors.
> > >>>>>>>
> > >>>>>>> However, there is still an issue with enum classes when tying to
> > >>> compile
> > >>>>>>> the wrapper code. If I have this header file:
> > >>>>>>>
> > >>>>>>> enum class MyEnum : int;
> > >>>>>>> struct S
> > >>>>>>> {
> > >>>>>>> MyEnum myenum;
> > >>>>>>> };
> > >>>>>>>
> > >>>>>>> and I run SWIG and then try to compile the wrapper code as
> > follows:
> > >>>>>>>
> > >>>>>>> swig -php -c++ test.i
> > >>>>>>> g++ `php-config5 --includes` -fpic -c -std=c++11 test_wrap.cpp
> > >>>>>>>
> > >>>>>>> I get the following errors:
> > >>>>>>>
> > >>>>>>> test_wrap.cpp: In function 'void _wrap_S_myenum_get(int, zval*,
> > >>> zval**, zval*, int)':
> > >>>>>>> test_wrap.cpp:1146:5: error: cannot convert 'MyEnum' to 'long
> > >>> int' in assignment
> > >>>>>>>
> > >>>>>>> The problem is with the following line in the function
> > >>> _wrap_S_myenum_get():
> > >>>>>>>
> > >>>>>>> (*return_value).value.lval = result;
> > >>>>>>>
> > >>>>>>> The LHS is of type 'long', but the RHS is of type 'MyEnum', and
> > >>> C++11 does not allow
> > >>>>>>> an implicit conversion between them. Rather, a cast is needed:
> > >>>>>>>
> > >>>>>>> (*return_value).value.lval = (long)result;
> > >>>>>>>
> > >>>>>>> Would it be possible to fix this?
> > >>>>>>
> > >>>>>> Fixed this for php now.
> > >>>>>
> > >>>>> Thanks! One more error related to enum classes :)
> > >>>>>
> > >>>>> Header file:
> > >>>>>
> > >>>>> enum class MyEnum {A, B};
> > >>>>>
> > >>>>> The wrapper code fails to compile, this time for both php and
> > >>> python (and maybe others
> > >>>>> I haven't tried).
> > >>>>>
> > >>>>> For php the error is:
> > >>>>>
> > >>>>> test_wrap.cpp: In function 'int zm_startup_test(int, int)':
> > >>>>> test_wrap.cpp:1397:1: error: 'A' was not declared in this scope
> > >>>>> test_wrap.cpp:1398:1: error: 'B' was not declared in this scope
> > >>>>>
> > >>>>> The problem is the following line:
> > >>>>>
> > >>>>> SWIG_LONG_CONSTANT(A, A);
> > >>>>>
> > >>>>> which expands to:
> > >>>>>
> > >>>>> zend_register_long_constant((char*)"A", sizeof("A"), A, (1<<0) |
> > >>> (1<<1), module_number )
> > >>>>>
> > >>>>> That should instead be:
> > >>>>>
> > >>>>> zend_register_long_constant((char*)"A", sizeof("A"), MyEnum::A,
> > >>> (1<<0) | (1<<1), module_number )
> > >>>>>
> > >>>>> (note the explicit qualification on MyEnum::A).
> > >>>>>
> > >>>>> Thanks,
> > >>>>> Nate
> > >>>>>
> > >>>
> > >>> Any chance this could be fixed?
> > >> My aim is to put the C++11 support into the next or next but one
> > release
> > >> and to fix most (if not all) the known C++11 problems for that
> > release.
> > >
> > > Ok, thanks. Do you have an idea about the timing of these releases?
> Mmm, it really depends on what eats up my free time. I'd hope to put it
> out around July.
This is now fixed in the gsoc2009-matevz branch if you want to try it out.

William