Mailman 3 June 2008 - Cplusplus-sig

[Graph] Problem Compiling BGL-Python
by ZSS June 12, 2008

June 12, 2008

Hi, I'm facing difficulty in compiling BGL-Python (which I'm not familiar with). I followed all the instructions in the README file, however, when I reach the stage where I need to run bjam I recieve this error: error: Could not find parent for project at '.' error: Did not find Jamfile.jam or Jamroot.jam in any parent directory. However, when I move the bgl-python-0.9 directory and put it under boost_1_35_0 I get a different error message: Jamfile:13: in modules.load rule project-root unknown in module Jamfile I don't know what to do, any hints are highly appreciated. Thank you, Zee

1 0

Boost.Python : Protected Destructor
by Brian O'Kennedy June 12, 2008

June 12, 2008

Hi, I'm trying to wrap a class like the one below which has a protected dtor and should be destructed via the Destroy method. class Foo { public: int bar() { return 1; } void Destroy() { delete this; } protected: ~Foo() { Destroy(); } }; My Boost.Python code looks like this: class_< Foo, boost::noncopyable > ("Foo", no_init ) .def( "bar", &Foo::bar ); I had to add both the boost::noncopyable and the no_init to stop compilation errors, but this means that I have no way of creating Foo from within Python. I can get around this by creating a factory method and registering the pointer: boost::shared_ptr< Foo > FooCreator() { return boost::shared_ptr< Foo >( new Foo(), boost::bind( &Foo::Destroy, _1 ) ); } And def("FooCreator", FooCreator ); register_ptr_to_python< boost::shared_ptr< Foo > >(); This feels a little clunky though. Am I doing something very wrong? Is there an easier way to manage classes like this with protected destructors? Thanks, Brian ________________________________________________________________________ This e-mail, and any attachment, is confidential. If you have received it in error, do not use or disclose the information in any way, notify me immediately, and please delete it from your system. ________________________________________________________________________

1 0

Py++: Class registration code insertion order (patch)
by Jason Kankiewicz June 12, 2008

June 12, 2008

In order to solve a registration order problem, I needed to make my hand-written method overload get registered prior to the method overloads generated by Py++. I have patched the pyplusplus.decl_wrappers.class_t class to provide the same control over registration code insertion order that the pyplusplus.module_builder.module_builder_t class provides. I have also patched the pyplusplus.module_creator.creator_t class to utilize the new registration code retrieval properties of the pyplusplus.decl_wrappers.class_t class. The attached patch is against r1326 of pyplusplus_dev. diff -ubr pygccxml\pyplusplus_dev/pyplusplus/decl_wrappers/class_wrapper.py patched\pyplusplus_dev/pyplusplus/decl_wrappers/class_wrapper.py --- pygccxml\pyplusplus_dev/pyplusplus/decl_wrappers/class_wrapper.py 2008-06-03 07:22:01.028286400 -0700 +++ patched\pyplusplus_dev/pyplusplus/decl_wrappers/class_wrapper.py 2008-06-11 07:31:14.570512000 -0700 @@ -178,7 +178,8 @@ self._held_type = None self._noncopyable = None self._wrapper_alias = None - self._registration_code = [] + self._registration_code_head = [] + self._registration_code_tail = [] self._declaration_code = [] self._wrapper_code = [] self._null_constructor_body = '' @@ -236,17 +237,33 @@ def declaration_code( self ): """ List of strings, that contains valid C++ code, that will be added to - the class registration section + the class declaration section """ return self._declaration_code @property + def registration_code_head( self ): + """ + List of strings, that contains valid C++ code, that will be added to + the head of the class registration section + """ + return self._registration_code_head + + @property + def registration_code_tail( self ): + """ + List of strings, that contains valid C++ code, that will be added to + the tail of the class registration section + """ + return self._registration_code_tail + + @property def registration_code( self ): """ List of strings, that contains valid C++ code, that will be added to the class registration section """ - return self._registration_code + return self._registration_code_head + self._registration_code_tail @property def wrapper_code( self ): @@ -311,13 +328,20 @@ """adds the code to the declaration section""" self.declaration_code.append( user_text.user_text_t( code ) ) - def add_registration_code( self, code, works_on_instance=True ): + def add_registration_code( self, code, works_on_instance=True, tail=True ): """adds the code to the class registration section - works_on_instance: If true, the custom code can be applied directly to obj inst. + @param works_on_instance: If true, the custom code can be applied directly to obj inst. Example: ObjInst."CustomCode" + @type works_on_instance: bool + + @param tail: if True, the custom code is appended to the class registration code. + @type tail: bool """ - self.registration_code.append( user_text.class_user_text_t( code, works_on_instance ) ) + if tail: + self._registration_code_tail.append( user_text.class_user_text_t( code, works_on_instance ) ) + else: + self._registration_code_head.append( user_text.class_user_text_t( code, works_on_instance ) ) #preserving backward computability add_code = add_registration_code diff -ubr pygccxml\pyplusplus_dev/pyplusplus/module_creator/creator.py patched\pyplusplus_dev/pyplusplus/module_creator/creator.py --- pygccxml\pyplusplus_dev/pyplusplus/module_creator/creator.py 2008-04-08 06:27:48.266729600 -0700 +++ patched\pyplusplus_dev/pyplusplus/module_creator/creator.py 2008-06-11 07:17:52.997907200 -0700 @@ -245,9 +245,13 @@ for cls_creator in class_creators: cls_decl = cls_creator.declaration #uc = user code - uc_creators = map( lambda uc: ctext_t( uc.text, uc.works_on_instance ) - , cls_decl.registration_code ) - cls_creator.adopt_creators( uc_creators ) + uc_creators_head = map( lambda uc: ctext_t( uc.text, uc.works_on_instance ) + , cls_decl.registration_code_head ) + cls_creator.adopt_creators( uc_creators_head, 0 ) + + uc_creators_tail = map( lambda uc: ctext_t( uc.text, uc.works_on_instance ) + , cls_decl.registration_code_tail ) + cls_creator.adopt_creators( uc_creators_tail ) uc_creators = map( lambda uc: ctext_t( uc.text ), cls_decl.wrapper_code ) if uc_creators:

2 1

boost.python not working in Visual Studio 2005?
by Grant June 10, 2008

June 10, 2008

Hi, I am using Python 2.5.2 installed from msi file downloaded from pyhton.org. I have a project which compiles and works in Visual Studio 2003 C++ on WinXP. Now I switch to Visual Studio 2005 C++ compiler. I compiled my boost.python 1.34.1 with VS2005, then compiled my project with this boost.python library. The compilation goes OK, but I can not import any library into python. The Python interpreter just complian no such library file exist. I check the path should be fine. I even change to the library path to import it, but still no luck. Then I tried boost.python 1.35, compiled it with VS2005. But it's the same result. I checked my dll library and the python library, I notice the python2.5 library is compiled with VS2003, since it linked to VS2003 runtime. Could that be the problem? Should I compile Python 2.5.2 from source with VS2005? Thanks for your help, Grant

4 4

Re: [C++-sig] boost.python not working in Visual Studio 2005?
by Tang, Guang June 10, 2008

June 10, 2008

"Nat Goodspeed" <nat(a)lindenlab.com> wrote in message news:<484DC4F6.4000602(a)lindenlab.com>... > Grant wrote: > > > The compilation goes OK, but I can not import any > > library into python. The Python interpreter just complian no such library > > file exist. I check the path should be fine. > > > > I checked my dll library and the python library, I notice the python2.5 > > library is compiled with VS2003, since it linked to VS2003 runtime. Could > > that be the problem? Should I compile Python 2.5.2 from source with VS2005? > > Did you just change to Python 2.5? You said you're building a .dll > library? Try renaming that to .pyd. See the last item on this page: > http://docs.python.org/whatsnew/ports.html#SECTION0001510000000000000000 > > If Python finds the extension module but detects a version mismatch, you > usually get a different error. Thank you nat. This solves my problem. Grant

1 0

Py++ exposing default constructors twice?
by Hans Meine June 9, 2008

June 9, 2008

Hi, py++ generates code like this: bp::class_< Foo >( "Foo" ) .def( bp::init< >() ) ... AFAIK, the first like already exposes the default constructor (since no_init was not given), thus I would expect the second line to be superfluous?! Ciao, / / .o. /--/ ..o / / ANS ooo

2 1

Help with problem caused going from boost_1_33_1 to 1_35_0
by Tony Kirke June 9, 2008

June 9, 2008

Hi, My c++ code that worked fine for Boost_1_33_1 (building with v1 system) is now giving the following error with 1_35_0: Boost.Python.ArgumentError: Python argument types in spucb.butterworth_iir.butterworth_iir(iir_coeff, float) did not match C++ signature: butterworth_iir(iir_coeff {lvalue}, float) I done a lot of searching to find out what changed in the newer Boost/boost build system and could not figure out what to do. Below is all of the code for a simple testcase. Since I have lots of code that is broken in this way, I'm wondering if there is an easy change that can be made to the boost wrapping code (or source itself) to make this functional. Is there a simple example of how this problem is solved. Was there a fundamental reason this is no longer supported? Thanks Tony ------------------------------------------ class iir_coeff { public: long order; public: iir_coeff(long ord=1); ~iir_coeff(); }; ------------------------------------------ #include "iir_coeff.h" iir_coeff::iir_coeff(long ord) { order = ord; } iir_coeff::~iir_coeff() {} ------------------------------------------ // Boost Includes ============================================================== #include <boost/python.hpp> #include <boost/cstdint.hpp> // Includes ==================================================================== #include "iir_coeff.h" // Using ======================================================================= using namespace boost::python; // Module ====================================================================== BOOST_PYTHON_MODULE(iir_coeff) { class_< iir_coeff >("iir_coeff", init< const iir_coeff& >()) .def(init< optional< long int > >()) .def_readwrite("order", &iir_coeff::order) ; } ------------------------------------------ #include "iir_coeff.h" void butterworth_iir(iir_coeff& filt, float fcd); ------------------------------------------ #include "butterworth_iir.h" void butterworth_iir(iir_coeff& filt, float fcd) { long order = filt.order; filt.order = order+1; } ------------------------------------------ // Boost Includes ============================================================== #include <boost/python.hpp> #include <boost/cstdint.hpp> // Includes ==================================================================== #include "butterworth_iir.h" // Using ======================================================================= using namespace boost::python; // Module ====================================================================== BOOST_PYTHON_MODULE(butterworth_iir) { def("butterworth_iir", &butterworth_iir); } ------------------------------------------ use-project boost : ../../boost_1_35_0 ; project : requirements <library>/boost/python//boost_python/<link>static : usage-requirements <include>../../boost_1_35_0 <include>. ; lib spuc : butterworth_iir.cpp iir_coeff.cpp : <include>. <include>../../boost_1_35_0 ; alias staticspuc : spuc/<link>static ; import python ; python-extension butterworth_iir : py_butterworth_iir.cpp : <include>. <include>../../boost_1_35_0 : <library>staticspuc ; python-extension iir_coeff : py_iir_coeff.cpp : <include>. <include>../../boost_1_35_0 : <library>staticspuc ; install dist : __init__.py butterworth_iir iir_coeff : <location>/usr/lib/python2.4/site-packages/spucb ; ------------------------------------------ boost-build ../../boost_1_35_0/tools/build/v2 ; ------------------------------------------ from spucb.butterworth_iir import * from spucb.iir_coeff import * x=iir_coeff(8) butterworth_iir(x,0.24) print x.order ------------------------------------------ Traceback (most recent call last): File "tes.py", line 4, in ? butterworth_iir(x,0.24) Boost.Python.ArgumentError: Python argument types in spucb.butterworth_iir.butterworth_iir(iir_coeff, float) did not match C++ signature: butterworth_iir(iir_coeff {lvalue}, float)

1 0

Problem extending python (using external DLL)
by Aurélien MAIGNAN June 6, 2008

June 6, 2008

Hi I've got a problem that need an more exp person than me to deal with it : I've got a naive class for testing interfacing with python using boost.python. Since we use OSG 1.2 for our work, I also wanted to do basic stuff using this library (http://www.openscenegraph.org/projects/osg/wiki/Downloads/PreviousReleasess… 1.2 version of OSG) problem is that doesn't work anymore when using this lib. So i worked around this issue and after a while (up to now in fact) it result in this more simple problem (minimize the code to highlight the problem) : I have a code like this in C++ : .h #ifndef HELLOMONDE_H #define HELLOMONDE_H #include <string> #include <iostream> #include <GL/glaux.h> #include <osg/Node> #include <osg/Group> #include <osg/Geode> #include <osg/Geometry> #include <osg/Texture2D> #include <osg/MatrixTransform> #include <osgDB/FileUtils> #include <osgDB/FileNameUtils> #include <osgText/Text> #include <osgText/Font> #include <osgText/String> #include <osgProducer/Viewer> #include <osg/PositionAttitudeTransform> #include <boost/python.hpp> using namespace std; using namespace boost::python; class PyCpp { private : string _s; bool misFileNameNativeStyle(const std::string& fileName) { #ifdef WIN32 return fileName.find('/') == std::string::npos; // return true if no unix style slash exist #else return fileName.find('\\') == std::string::npos; // return true if no windows style slash exist #endif }; public : PyCpp(string s); void call_myfunc(); void set(string s); string get(); }; inline void PyCpp::set(string s){_s = s;} inline string PyCpp::get(){return _s;} #endif .c++ #include "PyCpp.h" using namespace std; PyCpp::PyCpp(string s):_s(s){} void PyCpp::call_myfunc() { std::string ap = "C:/WINDOWS/Fonts/impact.ttf"; misFileNameNativeStyle(ap); // * LINE 1 * osgDB::isFileNameNativeStyle(ap);// * LINE 2 * } wrapping file : .cpp // This file has been generated by Py++. #include "boost/python.hpp" #include "f:/testpythoncpp/pycpp/pycpp.h" namespace bp = boost::python; BOOST_PYTHON_MODULE(PyCpp_ext){ bp::class_< PyCpp >( "PyCpp", bp::init< std::string >(( bp::arg("s") )) ) .def( "get" , &::PyCpp::get ) .def( "set" , &::PyCpp::set , ( bp::arg("s") ) ) .def( "call_myfunc" , &::PyCpp::call_myfunc ); bp::implicitly_convertible< std::string, PyCpp >(); } .py (for the local test) import PyCpp_ext myPy = PyCpp_ext.PyCpp("bonjour monde") print myPy.get() myPy.call_myfunc() osgDB::FileNameUtils.cpp .... blablabla .... bool osgDB::isFileNameNativeStyle(const std::string& fileName) { #ifdef WIN32 return fileName.find('/') == std::string::npos; // return true if no unix style slash exist #else return fileName.find('\\') == std::string::npos; // return true if no windows style slash exist #endif } .... blablabla .... So as you can see i rewrote my own osgDB::isFileNameNativeStyle() function (called misFileNameNativeStyle()) and the inner code is the same and finally the jamroot file : # Copyright David Abrahams 2006. Distributed under the Boost # Software License, Version 1.0. (See accompanying # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) # Specify the path to the Boost project. If you move this project, # adjust this path to refer to the Boost root directory. use-project boost : "C:/Program Files/boost/boost_1_35_0" ; # Set up the project-wide requirements that everything uses the # boost_python library from the project whose global ID is # /boost/python. project : requirements <library>/boost/python//boost_python <library>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/lib/osg.lib <library>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/lib/osgProducer.lib <library>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/lib/osgText.lib <library>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/lib/osgGA.lib <library>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/lib/osgDB.lib <library>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/lib/Producer.lib : requirements <include>C:/libs/OSG_OP_OT-1.2/OpenSceneGraph/include ; # Declare the three extension modules. You can specify multiple # source files after the colon separated by spaces. python-extension PyCpp_ext : bindings.cpp PyCpp.h PyCpp.cpp ; # A little "rule" (function) to clean up the syntax of declaring tests # of these extension modules. local rule run-test ( test-name : sources + ) { import testing ; testing.make-test run-pyd : $(sources) : : $(test-name) ; } # Declare test targets run-test hello : PyCpp_ext PyCpp.py ; So what's happen when using the bjam tools ? : --> When * LINE 1 * is commented (/* */) or not the local test crash : you can see a beautiful "send me a report" Microsoft style from python .exe with this AppName: python.exe AppVer: 0.0.0.0 ModName: msvcr80.dll ModVer: 8.0.50727.1433 Offset: 000503e2 --> When * LINE 2 * is commented (/* */) it works ! Ok so i gone further in this and since I've access to the osg sources i decided to recompile and rebuild the osgDB.dll osgDB::FileNameUtils.cpp has been modified like this : bool osgDB::isFileNameNativeStyle(const std::string& fileName) { fileName.find('/'); // * LINE 3 * return true; } and the resulting new osdDB.dll generated used for the local test Again what's happen ? : --> When * LINE 3 * is commented (/* */) it works ! --> When * LINE 3 * isn't commented (/* */) it crash in the same way !!! My guess is it's about the std::string::find(char) function .... but if so, why does it work when called in my own function misFileNameNativeStyle() ???? If anyone could help me with this ;) thanks, Aurélien MAIGNAN

1 0

ctypes newbie question
by Gary Robinson June 5, 2008

June 5, 2008

On OS X 10.5.3, with Python 2.5.2, I have the following C function, called test2.c: ============== double testreturn(void) { return 105.0; } ============== I also have the following Python script: ============== from ctypes import * testreturnproto = CFUNCTYPE(c_double) testreturn = testreturnproto(CDLL('test2.dylib').testreturn) print 'prototype version returned: ', testreturn() testdll = CDLL('test2.dylib') testdll.testreturn.restype = c_double print 'non-prototype version returned:', testdll.testreturn() ============= Based on reading the ctypes docs, I would expect the output of the script to be: prototype version returned: 105.0 non-prototype version returned: 105.0 However, what I actually get is: prototype version returned: 872440.0 non-prototype version returned: 105.0 If I modify the python script by commenting out the assignment to restype, the new script and results are: ================ from ctypes import * testreturnproto = CFUNCTYPE(c_double) testreturn = testreturnproto(CDLL('test2.dylib').testreturn) print 'prototype version returned: ', testreturn() testdll = CDLL('test2.dylib') #testdll.testreturn.restype = c_double print 'non-prototype version returned:', testdll.testreturn() ================ prototype version returned: 872440.0 non-prototype version returned: 872440 I assume that this means that the double 105.0 is being interpreted as if it were an int, since the default result type as an int. What I don't understand is why the line testreturnproto = CFUNCTYPE(c_double) is apparently not causing the return type to be properly interpreted as a double. We know that it's ultimately causing a Python float to be created, since the printed output ends with .0. So it has received the information that the number is supposed to be a float. But it's still interpreting it as an int before instantiating it as a float. The ctypes reference describes CFUNCTYPE as follows: > CFUNCTYPE(restype, *argtypes) > The returned function prototype creates functions that use the > standard C calling convention. I am passing c_double as restype. So why is it apparently interpreting the result as an int? I guess I don't understand the purpose of instantiating a prototype with CFUNCTYPE if it doesn't take care of interpreting the result as the type you give it. Any insight/help would be appreciated. Thanks, Gary -- Gary Robinson CTO Emergent Music, LLC personal email: garyrob(a)mac.com work email: grobinson(a)emergentmusic.com Company: http://www.emergentmusic.com Blog: http://www.garyrobinson.net

2 1

inheritance and virtual callbacks
by Matthew Scouten June 5, 2008

June 5, 2008

So I have 2 classes, foo and bar. bar is a subclass of foo. Both bar and foo have virtual functions intended to be overridden form python. struct foo { foo(){} ; foo(int init_x, int init_y){x=init_x;y=init_y;}; int x; int y; virtual void FooCallback(){std::cout << "default foo called" << std::endl;}; }; struct bar : foo { bar(){} ; bar(int init_x, int init_y, int init_z):foo(init_x,init_y){z = init_z;}; virtual void BarCallback(){std::cout << "default bar called" << std::endl;}; int z; }; struct foo_wrapper : foo , wrapper<foo> { foo_wrapper(); foo_wrapper(const foo& f); foo_wrapper(int init_x, int init_y); virtual void FooCallback(); }; void foo_wrapper::FooCallback() { std::cout << "atemptting foo callback" << std::endl; if (override func = this->get_override("FooCallback")) { func(); return; } else std::cout << "foo callback function not found" << std::endl; } foo_wrapper::foo_wrapper(const foo& exch): foo(exch), wrapper<foo>(){} foo_wrapper::foo_wrapper(): foo(), wrapper<foo>(){} foo_wrapper::foo_wrapper(int init_x, int init_y) : foo(init_x,init_y), wrapper<foo>(){} struct bar_wrapper: bar, wrapper<bar> { bar_wrapper(); bar_wrapper(const bar& b); bar_wrapper(int init_x, int init_y, int init_z); virtual void BarCallback(); }; bar_wrapper::bar_wrapper(const bar& exch): bar(exch), wrapper<bar>(){} bar_wrapper::bar_wrapper(): bar(), wrapper<bar>(){} bar_wrapper::bar_wrapper(int init_x, int init_y, int init_z) : bar(init_x, init_y, init_z), wrapper<bar>(){} void bar_wrapper::BarCallback() { std::cout << "atemptting bar callback" << std::endl; if (override func = this->get_override("BarCallback")) { func(); return; } else std::cout << "bar callback function not found" << std::endl; } void backcaller(bar& b) { b.BarCallback(); b.FooCallback(); } BOOST_PYTHON_MODULE(busybox) { class_<foo_wrapper>("foo") .def(init<>()) .def(init<int, int>()) .ENABLE_COPY(foo) .def_readwrite("x", &foo::x ) .def_readonly ("y", &foo::y ) ; class_<bar_wrapper, bases<foo> >("bar") .def(init<>()) .def(init<int,int,int>()) .ENABLE_COPY(bar) .def_readwrite("z", &bar::z) ; def("backcaller", &backcaller); } in python: >>> import busybox >>> class myBar(busybox.bar): ... def FooCallback(self): ... print "this is a foo callback" ... def BarCallback(self): ... print "this is a bar callback" ... >>> b = myBar() >>> busybox.backcaller(b) atemptting bar callback this is a bar callback default foo called >>> So the question is: why is the default FooCallback in foo getting called rather then the FooCallback in myBar? What can I do about it?

2 6