Boost Python issue with converters

From: Dominik Cirmirakis (dcirmirakis_at_[hidden])
Date: 2020-06-23 19:50:15

Hi,

I have a question regarding the below code.

It's an example how to pass a custom class via shared_ptr to embedded 
python code and it works when boost is dynamically linked.

Unfortunately the same code with statically linked boost doesn't work 
with the following error message:

"No to_python (by-value) converter found for C++ type: class 
boost::shared_ptr<class Foo>".

I don't understand why a different linking can affect type recognition 
of a registered converter. What am I missing?

Can anybody help me out?

Thanks,

Dominik

https://stackoverflow.com/questions/8225934/exposing-a-c-class-instance-to-a-python-embedded-interpreter?noredirect=1&lq=1

|#include<boost/shared_ptr.hpp>#include<boost/make_shared.hpp>#include<boost/python.hpp>#include<string>#include<iostream>namespacebp 
=boost::python;structFoo{Foo(){}Foo(std::stringconst&s):m_string(s){}voiddoSomething(){std::cout 
<<"Foo:"<<m_string 
<<std::endl;}std::stringm_string;};typedefboost::shared_ptr<Foo>foo_ptr;BOOST_PYTHON_MODULE(hello){bp::class_<Foo,foo_ptr>("Foo").def("doSomething",&Foo::doSomething);};|

|#include<boost/shared_ptr.hpp>#include<boost/make_shared.hpp>#include<boost/python.hpp>#include<string>#include<iostream>namespacebp 
=boost::python;structFoo{Foo(){}Foo(std::stringconst&s):m_string(s){}voiddoSomething(){std::cout 
<<"Foo:"<<m_string 
<<std::endl;}std::stringm_string;};typedefboost::shared_ptr<Foo>foo_ptr;BOOST_PYTHON_MODULE(hello){bp::class_<Foo,foo_ptr>("Foo").def("doSomething",&Foo::doSomething);};intmain(intargc,char**argv){Py_Initialize();try{PyRun_SimpleString("a_foo 
= None\n""\n""def setup(a_foo_from_cxx):\n"" print 'setup called with', 
a_foo_from_cxx\n"" global a_foo\n"" a_foo = a_foo_from_cxx\n""\n""def 
run():\n"" a_foo.doSomething()\n""\n""print 'main module 
loaded'\n");foo_ptr a_cxx_foo 
=boost::make_shared<Foo>("c++");inithello();bp::objectmain 
=bp::object(bp::handle<>(bp::borrowed(PyImport_AddModule("__main__"))));// 
pass the reference to a_cxx_foo into python:bp::objectsetup_func 
=main.attr("setup");setup_func(a_cxx_foo);// now run the python 'main' 
functionbp::objectrun_func 
=main.attr("run");run_func();}catch(bp::error_already_set){PyErr_Print();}Py_Finalize();return0;}|