Mailman 3 August 2004 - Cplusplus-sig

RE: [C++-sig] Re: test/embedding.cpp in bpl 1.31
by Stefan Seefeld Aug. 13, 2004

Aug. 13, 2004

> -----Original Message----- > From: David Abrahams [mailto:dave@boost-consulting.com] > Sent: August 12, 2004 08:09 > > PythonDerived is a type object extracted from > > a python script, so the first line calls the > > constructor. The second takes the instance and > > extracts a 'Base' reference for later use. > > But what's the '()' operator supposed to do in > > that line ? > > It's a workaround for broken compilers. ok. May I suggest to add a little comment to avoid confusing the reader (and to remember developers to remove the workaround once support for those broken compilers has ended). [problems with PyRun_File...] > I don't have a comment about that part yet, and no time to make the > evaluation. That said, if you could package up a bjam-able example I > might find time to try it. All I'd do is look at it with the > debugger, though, and I guess you can do that just as well as I can. yep, and I did. As someone else confirmed, the problem was that the python runtime library had been compiled with vc 7.0, while I'm working with 7.1. It appears the FILE structure layout changed, so those two versions aren't binary compatible. I'm now recompiling python with vc 7.1... Thanks again, Stefan

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recompiling cpp-file
by Alexander Kollmann Aug. 13, 2004

Aug. 13, 2004

hi, i'm have no idea how to recompile a *.cpp for a certain python version. how can i do that ? regards alex

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RE: [C++-sig] Re: test/embedding.cpp in bpl 1.31
by Stefan Seefeld Aug. 12, 2004

Aug. 12, 2004

> -----Original Message----- > From: David Abrahams [mailto:dave@boost-consulting.com] > Sent: August 12, 2004 10:07 > > (and to remember developers to remove the workaround once support > > for those broken compilers has ended). > > When BPL ends support for vc6/7 we will have a complete rewrite with > many new interfaces. Or did you mean "...and to remind users..." yeah, everybody looking at the code (for inspiration, if nothing else) who is not familiar with all those compiler-specific workarounds. Regards, Stefan

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test/embedding.cpp in bpl 1.31
by Stefan Seefeld Aug. 12, 2004

Aug. 12, 2004

hi there, debugging my applications, I'v had a closer look into the test/embedding.cpp file, and I'd like to suggest two changes, one cosmetic, and one fix. The fix concerns line line 108/109, which read: python::object py_base = PythonDerived(); Base& py = python::extract<Base&>(py_base)(); PythonDerived is a type object extracted from a python script, so the first line calls the constructor. The second takes the instance and extracts a 'Base' reference for later use. But what's the '()' operator supposed to do in that line ? If I remove it, the test still performs correctly, so it seems it doesn't have any effect (at least in this context). Can anybody explain this behavior ? The other change concerns the way the 'PythonDerived' type object is obtained. Instead of running 'PyRun_String' I'd just extract it from the 'main_namespace' dictionary after the first script has been evaluated: python::object PythonDerived = main_namespace["PythonDerived"]; Both changes are contained in the attached patch... --- My original goal looking into this file was to understand a crash I get when running 'PyRun_File', so I tried to do what the comment in embedding.cpp suggests, i.e. I put the script defining the 'PythonDerived' class into a separate file and then use 'PyRun_File' to evaluate that script instead of 'PyRun_String'. While this works fine on linux, the application crashes on windows (msvc) somewhere inside the PyRun_File call. I did the appropriate (I think) changes to 'test/embedding.cpp' for comparison, and I observed the same crash (i.e. just recompiling the modified 'embedding' test inside the boost build system). I'd very much appreciate if anybody could either confirm this behavior on windows (msvc) or show what changes need to be done to the code to make it work. (I believe this use case is sufficiently important to warrant a demo /test in its own right.) Thanks a lot ! Stefan 93,98c93 < python::handle<> class_ptr( < PyRun_String("PythonDerived\n", Py_eval_input, < main_namespace.ptr(), main_namespace.ptr()) ); < < // Wrap the raw Python object in a Boost.Python object < python::object PythonDerived(class_ptr); --- > python::object PythonDerived = main_namespace["PythonDerived"]; 109c104 < Base& py = python::extract<Base&>(py_base)(); --- > Base& py = python::extract<Base&>(py_base);

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Boost::Python 1.13.1 on SuSE 9.1 x86_64
by Jan Heiser Aug. 11, 2004

Aug. 11, 2004

Hi there, I have successfully compiled Boost 1.31.1 on SuSE 9.1 x86_64 (with the regex patch and the SuSE 9.x patch published in this list/newsgroup). It worked. However, when I tried to compile some code written for Boost::python, I ran into the following problem (compiling with -Wall -Werror) : /usr/local/include/boost-1_31/boost/python/with_custodian_and_ward.hpp: In static member function `static PyObject* boost::python::with_custodian_and_ward_postcall<custodian, ward, BasePolicy_>::postcall(const ArgumentPackage&, PyObject*) [with ArgumentPackage = PyObject*, long unsigned int custodian = 0, long unsigned int ward = 1, BasePolicy_ = boost::python::default_call_policies]': /usr/local/include/boost-1_31/boost/python/detail/caller.hpp:201: instantiated from `PyObject* boost::python::detail::caller_arity<1>::impl<F, Policies, Sig>: :operator()(PyObject*, PyObject*) [with F = XXX, Policies = boost::python::return_internal_reference<1, boost: :python::default_call_policies>, Sig = boost::mpl::vector2<XXX,YYY>]' /usr/local/include/boost-1_31/boost/python/object/py_function.hpp:39: instanti ated from `PyObject* boost::python::objects::caller_py_function_impl<Caller>::op erator()(PyObject*, PyObject*) [with Caller = boost::python::detail::caller<XXX () const, boost::python::return_internal_reference<1, boost::python::default_call_policies>, boost::mpl::vector2<XXX,YYY> >]' /usr/local/include/boost-1_31/boost/mpl/if.hpp:75: instantiated from here /usr/local/include/boost-1_31/boost/python/with_custodian_and_ward.hpp:89: warning: comparison is always false due to limited range of data type It boils down to the fact that on x86_64 unsigned and std::size_t do not have the same width, unsigned still has 32 bits, std::size_t has 64 bits. Now, my idea was to directly change the template function: boost/python/with_custodian_and_ward.hpp:79 - template <std::size_t custodian, std::size_t ward, class BasePolicy_ = default_call_policies> + template <unsigned custodian, unsigned ward, class BasePolicy_ = default_call_policies> Now my questions: Has anybody else in the world dared to compile and use Boost::python on Linux x86_64 or another 64bit OS? Is the proposed change sensible or does it more damage than it heals? (probably there are more places to change accordingly, though) How to get that into CVS? Jan

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new idea for pyste
by Roman Yakovenko Aug. 10, 2004

Aug. 10, 2004

Hi. I am working with pyste for an year. It is very good tool for small projects. One thing that confuse me is passing arguments to pyste. I need to write an other script, that will run\configure pyste. ( I working on windows so an other script is batch file ). I prefer an other way. To export object called environment, that will have all necessary pyste configuration stuffs. For example: class environment(object): def __init__(self): self.__gccxml_path = 'gccxml.exe' #gccxml.exe should be in PATH self.__include_pathes = [] self.__module_name = None ... def __get_gccxml_path( self ): return self.__gccxml_path def __set_gccxml_path( self, gccxml_path ): self.__gccxml_path = gccxml_path gccxml_path = property( __get_gccxml_path, __set_gccxml_path ) ... I think that moving this direction is good for a few reasons. One of them is - it will cancel pyste files as special purpose files. Those files will be regular python scripts. Also I think that this will simplifier pyste. Example: ( pseudo code ) env = environment() env.gccxml_path = r'c:\gccxml\gccxml.exe' env.include_path = [ r'c:\boost_cvs', r'c:\whatever' ] env.use_namespace = 'py' env.debug = False env.working_directory = r'r'c:\development\repository_api\py_api' SetModuleName( 'PyRepository' ) for header_file in directory( r'c:\development\repository_api' ): AllFromHeader( header_file ) GenerateMain( 'PyRepository.cpp' ) What do you think about this? I would like to contribute pathces. Roman

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C++ classes intended for use with Python
by Itamar Shtull-Trauring Aug. 10, 2004

Aug. 10, 2004

Currently, if I want to have virtual methods overridable in Python I need to go through the whole wrapper class song and dance. Thing is, I am creating classes whose only goal is to integrate with Python. I'm not wrapping a C++ library, I'm writing a Python/C++ library. Is there any way I can have classes automatically get an appropriate PyObject* self argument when instantiated? Obviously they'd be only used by subclassing them in Python. -- Itamar Shtull-Trauring http://itamarst.org

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RE: [C++-sig] Re: new idea for pyste
by Roman Yakovenko Aug. 10, 2004

Aug. 10, 2004

From: Nicodemus > I think the idea is nice, but I would like to see what's the > improvement > over something like this: > ... > Regards, > Nicodemus. The main differences are: Pyste is library that helps user to export his classes Pyste files is regular python files, and not "... simple interface file ..." It is much easier to manage big projects: 1. No need in "file-list" file 2. better control over generation: ( example: I want to generate all classes from specific namespace, to an other file, right now Pyste support only generation from header file and then excluding all classes that I don't want to be exported. I think it could be much easier to write AllFromNamespace( 'repository', [ 'a.h', 'b.h', 'c.h' ] ) ( new functionality -> new Pyste options -> complicated command line -> additional script to run Pyste ) > import os > import sys > from Pyste import pyste > > # manipulate argv as needed > sys.argv.append(...) > > # add/find include directories at your leisure > sys.argv.append('-I') > sys.argv.append('my dir') > > pyste.main() > You are right: right now the difference between what I propose and what we have is small, but it completely change the future: instead of "code generator" + "interface files" + "options" we will have "code generation framework" + "scripts written in python" only. Roman

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Boost-Python
by Pedro Bola�os Aug. 10, 2004

Aug. 10, 2004

Hi, I've been trying to build boost-python both through the visual studio project file, and by using bjam. Either way I get the following output (errors): ------ Build started: Project: boost_python, Configuration: Debug Win32 ------ Compiling... type_id.cpp tuple.cpp str.cpp registry.cpp pickle_support.cpp ../../../../boost\python\args_fwd.hpp(46) : error C2118: negative subscript or subscript is too large ../../../../boost\python\args_fwd.hpp(47) : see reference to class template instantiation 'boost::python::detail::error::more_keywords_than_function_arguments<,>' being compiled object_protocol.cpp object_operators.cpp numeric.cpp module.cpp long.cpp list.cpp life_support.cpp iterator.cpp ../../../../boost\python\args_fwd.hpp(46) : error C2118: negative subscript or subscript is too large ../../../../boost\python\args_fwd.hpp(47) : see reference to class template instantiation 'boost::python::detail::error::more_keywords_than_function_arguments<,>' being compiled inheritance.cpp ../../../../boost\pending\detail\property.hpp(75) : error C2039: 'result<`template-parameter258'>' : is not a member of 'boost::detail::property_value_end<PropertyList>' ../../../../boost\pending\detail\property.hpp(75) : fatal error C1507: previous user errors and subsequent error recovery halt further compilation function.cpp ../../../../boost\python\args_fwd.hpp(46) : error C2118: negative subscript or subscript is too large ../../../../boost\python\args_fwd.hpp(47) : see reference to class template instantiation 'boost::python::detail::error::more_keywords_than_function_arguments<,>' being compiled from_python.cpp errors.cpp enum.cpp dict.cpp class.cpp Generating Code... Compiling... builtin_converters.cpp \Desarrollo\boost_1_31_0\libs\python\src\converter\builtin_converters.cpp(78) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data \Desarrollo\boost_1_31_0\libs\python\src\converter\builtin_converters.cpp(71) : while compiling class-template member function 'void boost::python::converter::`anonymous-namespace'::slot_rvalue_from_python<T,SlotPolicy>::construct(PyObject *,boost::python::converter::rvalue_from_python_stage1_data *)' with [ T=float, SlotPolicy=boost::python::converter::`anonymous-namespace'::float_rvalue_from_python ] \Desarrollo\boost_1_31_0\libs\python\src\converter\builtin_converters.cpp(397) : see reference to class template instantiation 'boost::python::converter::`anonymous-namespace'::slot_rvalue_from_python<T,SlotPolicy>' being compiled with [ T=float, SlotPolicy=boost::python::converter::`anonymous-namespace'::float_rvalue_from_python ] arg_to_python_base.cpp aix_init_module.cpp Generating Code... Build log was saved at "file://c:\Desarrollo\boost_1_31_0\libs\python\build\VisualStudio\debug-obj\BuildLog.htm" boost_python - 5 error(s), 1 warning(s) ---------------------- Done ---------------------- Build: 0 succeeded, 1 failed, 0 skipped What can I do about it? Am I doing something wrong? - I'm working on Windows XP - I'm using Microsoft Visual Studio .NET 2003 - I'm using Boost 1.31 and boost-jam 3.1.10 Thanks, Pedro Bolaños. _________________________________________________________________ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail

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make_constructor & keyword arguments?
by Ralf W. Grosse-Kunstleve Aug. 10, 2004

Aug. 10, 2004

Is it possible to add keyword argument support to a constructor injected with boost::python::make_constructor? I tried this .def("__init__", boost::python::make_constructor(from_iselection_unsigned), (arg_("size"), arg_("iselection"))) but it doesn't compile ("incomplete type"). I also tried using operator() and operator[] of the make_constructor instance; it compiles but doesn't work at runtime. What is the correct syntax? Thanks! Ralf __________________________________ Do you Yahoo!? Read only the mail you want - Yahoo! Mail SpamGuard. http://promotions.yahoo.com/new_mail

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