Mailman 3 October 2007 - Cplusplus-sig

access struct inside class
by Simon Norberg Oct. 16, 2007

Oct. 16, 2007

Hello, im trying to get python to read and write to a struct inside a class in the same way i do in c++ Customers hej; hej.address.contact = "The Devil"; but i cant even get the code to compile, any suggestions? #include <iostream> #include <string> using namespace std; class Customers { private: struct s_address { string contact; string street1; string street2; string city; string province; string postalCode; string country; }; public: s_address address; Customers(){} ~Customers(){} }; #include <boost/python.hpp> #include <boost/python/module.hpp> #include <boost/python/class.hpp> #include <boost/python/scope.hpp> #include <boost/python/def.hpp> using namespace boost::python; BOOST_PYTHON_MODULE(test) { scope outer= class_<Customers>("Customers") ; class_<Customers::address>("address") .def_readwrite("contact", &Customers::address.contact) ; } When i compile i get this error: test.cpp: In function ‘void init_module_test()’: test.cpp:36: error: ‘Customers::address’ cannot appear in a constant-expression test.cpp:36: error: template argument 1 is invalid test.cpp:18: error: invalid use of non-static data member ‘Customers::address’ test.cpp:37: error: from this location what i want to be able to do in python is from test import * cust = Customers() cust.address.contact = "Hello" print cust.address.contact

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Programmer Search @ Naughty Dog!
by Candace Walker Oct. 15, 2007

Oct. 15, 2007

Hi Hamilton, My name is Candace Walker and I am the recruiter at Naughty Dog in Santa Monica, CA. Naughty Dog is owned by Sony Computer Entertainment of America and is developer of the Crash Bandicoot and Jak and Daxter franchises. I wanted to reach out to you and let you Naughty Dog is active to staff up for solid engineers. Naughty Dog has two teams right now, our Game Team and our ICE Team. Our game team is working on a new original IP called, Uncharted: Drake's Fortune that debuted at E3 of 2006. I have provided the game trailer, along with some press about the game. Demo: www.naughtydog.com/comingsoon/index.html Press from: Uncharted: Drake's Fortune . "Naughty Dog's new franchise for the PS3 could be the biggest first-party title of the year." -Gamespy . "Naughty Dog has always had a reputation for squeezing the utmost performance and fidelity out of Sony's hardware, and it looks like that tradition will continue with Uncharted." -Gamespot (Gamespot Preview) In addition to our game team, Naughty Dog is home to the ICE Team, one of Sony's World Wide Studios central technology groups. The ICE Team focuses on creating core graphics technologies for Sony's worldwide first party published titles for the PLAYSTATIONR3, including low level game engine components, graphics processing pipelines, supporting tools, and GUI profiling and debugging tools. More recently the ICE Team's scope has expanded in order to build engine components and tools for use by third party developers. The first two of these are PLAYSTATIONREdge, a set of components that enables developers to get better performance out of the PLAYSTATIONR3, and GCM Replay, which provides analysis, debugging, and profiling for the RSXT. Please feel free to contact me directly if this is something that you or someone you know may be interested in hearing more about. Candace Walker Recruiter <http://www.linkedin.com/in/candacerwalker> http://www.linkedin.com/in/candacerwalker Naughty Dog, Inc. 1601 Cloverfield Blvd. Suite 6000 North Santa Monica, CA 90404 <mailto:candace_walker@naughtydog.com> candace_walker(a)naughtydog.com Phone: 310-633-9275 <http://www.naughtydog.com/> www.naughtydog.com

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Re: [C++-sig] wrapping a function that takes a void*
by English, Mark Oct. 12, 2007

Oct. 12, 2007

X-Replace-Address: mark.ignorethisbit.english(a)xxxrbccmxxx.ignorethisbittoo_and_removethosepreceding_xxxs_.com > No, I need the opposite of that. I have a reference to some python > object (any python object) that needs to be passed to a c++ function > expecting a (void *). Later, that object will be handed back to python > as a reference again. Ok. How about: int Special_wrapper::fooRequest(boost::python::object objUserData) { return fooRequest((void*) objUserData.ptr()); } ______________________________________________________________________ This email is intended only for the use of the individual(s) to whom it is addressed and may be privileged and confidential. Unauthorised use or disclosure is prohibited.If you receive This e-mail in error, please advise immediately and delete the original message. This message may have been altered without your or our knowledge and the sender does not accept any liability for any errors or omissions in the message.

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Re: [C++-sig] wrapping a function that takes a void*
by English, Mark Oct. 12, 2007

Oct. 12, 2007

X-Replace-Address: mark.ignorethisbit.english(a)xxxrbccmxxx.ignorethisbittoo_and_removethosepreceding_xxxs_.com > -----Original Message----- > From: c++-sig-bounces(a)python.org [mailto:c++-sig-bounces@python.org]On > Behalf Of Matthew Scouten > Sent: 12 October 2007 17:19 > To: Development of Python/C++ integration > Subject: [C++-sig] wrapping a function that takes a void* > > > I am wraping a function that takes a void* as an argument. Is an opaque pointer what you're looking for ? http://www.boost.org/libs/python/doc/v2/return_opaque_pointer.html Note there are some potential bugs in this. The PyTypeObject's name causes a crash I believe but I'm using boost 1.32, Python 2.3.6 so it may have been fixed by now in either of those. For example using the example code: >>> import opaque_ext >>> p = opaque_ext.get() >>> type(p) #Causes an access violation Cheers, mE ______________________________________________________________________ This email is intended only for the use of the individual(s) to whom it is addressed and may be privileged and confidential. Unauthorised use or disclosure is prohibited.If you receive This e-mail in error, please advise immediately and delete the original message. This message may have been altered without your or our knowledge and the sender does not accept any liability for any errors or omissions in the message.

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wrapping a function that takes a void*
by Matthew Scouten Oct. 12, 2007

Oct. 12, 2007

I am wraping a function that takes a void* as an argument. class Special { int fooRequest(void * userData = NULL); virtual void fooCallback(void * userData) } The intention is that the user data pointer will be returned to 'remind' the program what callback goes with what request. my first attempt: struct Special_wrapper: Special, wrapper<Special> { int fooRequest(PyObject * userData = NULL); } int Special_wrapper::fooRequest(PyObject * userData) { return fooRequest((void*) userData) } and later class<Special_wrapper>("Special") .def("fooRequest" ,&Special_wrapper::fooRequest ,(arg("userData") = (void*)NULL)) I get a error the first line of which is: C:\Documents and Settings\mscouten\Desktop\boost_1_32_0\boost_1_32_0\boost/python/converter/arg_to_python.hpp(181) : error C2027: use of undefined type 'boost::python::converter::detail::cannot_convert_raw_PyObject<T>' (Full error text available on request) Does any body have any recommendations about how I could wrap this.

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PyObject_Call() wrapper ?
by Stefan Seefeld Oct. 11, 2007

Oct. 11, 2007

I'm looking for the boost.python equivalent of the generic callable(*args, **kwds) i.e. a version of the call operator that takes an arguments vector as well as a keyword dictionary, instead of individual arguments. I can't find it. Is that not implemented ? May I submit a patch for it ? Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

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convert child class to child class {lvalue} ?
by Steven Wyckoff Oct. 11, 2007

Oct. 11, 2007

Hi all, I am trying to wrap some C++ code that involves an object factory and manager and I seem to be stumped by how boost is converting types. I have a base class and a few classes that inherit from it and a factory to create instances of these classes. Using the factory I can successfully create objects of the proper type. Following the tutorial I have virtual functions behaving properly. However, if I try to call methods that only exist in a child class, I get an Argument Error: ArgumentError: Python argument types in childobj.ChildOnly(childobj) did not match C++ signature: ChildOnly(struct childobj {lvalue}) I have tried writing a function that will cast the pointer to a child class pointer. This lets me call child only methods, but then i get the mirror error when I try to call base class methods. The confounding part is that it appears that the type information is correct in python. If I create an instance without using the factory (child = childobj()) then everything works just fine. I guess I could write converters to go both ways and just cast to whatever type I need for the current function call, but that is hardly ideal. If anyone has any suggestions about how I can get around this (maybe a type converter that I'm not aware of?) I would appreciate it. Here is my code: C++ code: ----------------------------------------------------------------------- struct baseobj { virtual std::string ID() {return std::string("BaseObj");} void SetVal(int v) {val = v;} int GetVal() {return val;} int val; }; struct childobj : public baseobj { virtual std::string ID() {return std::string("ChildObj");} std::string ChildOnly() {return "OK";} }; baseobj* createobj(std::string kind) { if(kind == "Base") { return new baseobj(); } else if(kind == "Child") { return new childobj(); } else { return NULL; } } childobj* CastToChild(baseobj* pobj) { return static_cast<childobj*>(pobj); } struct BaseWrap : baseobj, boost::python::wrapper<baseobj> { std::string ID() { if(boost::python::override f = this->get_override("ID")) return ID(); return baseobj::ID(); } std::string default_ID() {return this->baseobj::ID();} }; BOOST_PYTHON_MODULE(extending) { using namespace boost::python; class_<BaseWrap, boost::noncopyable>("baseobj") .def("ID", &baseobj::ID, &BaseWrap::ID, "Returns the ID of the object") .def("GetVal", &baseobj::GetVal) .def("SetVal", &baseobj::SetVal) ; class_<childobj, bases<BaseWrap> >("childobj") .def("ChildOnly", &childobj::ChildOnly) ; implicitly_convertible<childobj,baseobj>(); class_<objman>("objman") .def("SetObj", &objman::SetObj) .def("GetObj", &objman::GetObj, return_value_policy<reference_existing_object>()) ; def("create", &createobj, return_value_policy<manage_new_object>() ); def("callID", &callID ); def("CastToChild", &CastToChild, return_value_policy<reference_existing_object>()); } Python: ---------------------------------------------------------------------------- >>> from extending import * >>> base = create("Base") >>> base.ID() 'BaseObj' >>> child = create("Child") >>> child.ID() 'ChildObj' >>> child.ChildOnly() Traceback (most recent call last): File "<pyshell#3>", line 1, in <module> child.ChildOnly() ArgumentError: Python argument types in childobj.ChildOnly(childobj) did not match C++ signature: ChildOnly(struct childobj {lvalue}) >>> castchild = CastToChild(child) >>> castchild.ChildOnly() 'OK' >>> castchild.ID() Traceback (most recent call last): File "<pyshell#6>", line 1, in <module> castchild.ID() ArgumentError: Python argument types in baseobj.ID(childobj) did not match C++ signature: ID(struct BaseWrap {lvalue}) ID(struct baseobj {lvalue})

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Re: [C++-sig] Can boost python do these 2 things automatically?
by Chang Chen Oct. 11, 2007

Oct. 11, 2007

Hi All I am new to boost python. I have 2 questions for using boost python to wrap C++ API Our C++ API looks like this: class BImpl; Class B { public: B(){} Error DoSomething(); private: BImpl*; mpBImpl } class A { public: A(){} Error CreateB(B& bObj); private: ... } Our error handle strategy is returning an error code other than throwing exception. This is because throwing an exception across the DLL boundary is not safe. I want to wrap A and B with same C++ public interface in python, but #1 I want to return real object rather than retrieve object. i.e. in python, I would like users writing code like this: aObject = A() ~bObject = aObject.CreateB()~ #2 I want to throw an *python* exception rather than return an error code like c++. I do not know how to do it in Boost Python. Any suggestion? Chang

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Re: [C++-sig] convert child class to child class {lvalue} ?
by English, Mark Oct. 11, 2007

Oct. 11, 2007

> -----Original Message----- > From: c++-sig-bounces(a)python.org [mailto:c++-sig-bounces@python.org]On > Behalf Of Steven Wyckoff > Sent: 10 October 2007 22:53 > To: c++-sig(a)python.org > Subject: [C++-sig] convert child class to child class {lvalue} ? > > > Hi all, > > I am trying to wrap some C++ code that involves an object factory and > manager and I seem to be stumped by how boost is converting > types. <snip> > baseobj* createobj(std::string kind) > { > if(kind == "Base") > { > return new baseobj(); > } > else if(kind == "Child") > { > return new childobj(); > } > else > { > return NULL; > } > } Haven't tested this myself, but try something like: ---C++ code--- boost::shared_ptr<baseobj> createobj(std::string kind) { boost::shared_ptr<baseobj> ptrCreate; if(kind == "Base") { ptrCreate = new baseobj; } else if(kind == "Child") { ptrCreate = new childobj; } else { ptrCreate = NULL; } return ptrCreate; } ________________________________________ This E-Mail (including any attachments) may contain privileged or confidential information. It is intended only for the addressee(s) indicated above. The sender does not waive any of its rights, privileges or other protections respecting this information. Any distribution, copying or other use of this E-Mail or the information it contains, by other than an intended recipient, is not sanctioned and is prohibited. If you received this E-Mail in error, please delete it and advise the sender (by return E-Mail or otherwise) immediately. This E-Mail (including any attachments) has been scanned for viruses. It is believed to be free of any virus or other defect that might affect any computer system into which it is received and opened. However, it is the responsibility of the recipient to ensure that it is virus free. The sender accepts no responsibility for any loss or damage arising in any way from its use. E-Mail received by or sent from RBC Capital Markets is subject to review by Supervisory personnel. Such communications are retained and may be produced to regulatory authorities or others with legal rights to the information. IRS CIRCULAR 230 NOTICE: TO COMPLY WITH U.S. TREASURY REGULATIONS, WE ADVISE YOU THAT ANY U.S. FEDERAL TAX ADVISE INCLUDED IN THIS COMMUNICATION IS NOT INTENDED OR WRITTEN TO BE USED, AND CANNOT BE USED, TO AVOID ANY U.S. FEDERAL TAX PENALTIES OR TO PROMOTE, MARKET, OR RECOMMEND TO ANOTHER PARTY ANY TRANSACTION OR MATTER.

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Can boost python do these 2 things automatically?
by Chang Chen Oct. 11, 2007

Oct. 11, 2007

Hi All I am new to boost python. I have 2 questions for using boost python to wrap C++ API Our C++ API looks like this: class BImpl; Class B { public: B(){} Error DoSomething(); private: BImpl*; mpBImpl } class A { public: A(){} Error CreateB(B& bObj); private: ... } Our error handle strategy is returning an error code other than throwing exception. This is because throwing an exception across the DLL boundary is not safe. I want to wrap A and B with same C++ public interface in python, but #1 I want to return real object rather than return an error code. i.e. in python aObject = A() *bObject = aObject.CreateB()* #2 I want to throw an *python* exception rather than return an error code like c++. I do not know how to do it in Boost Python. Any suggestion? Chang

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