On 03/15/2012 09:22 AM, christophe jean-joseph wrote:

Hello

The situation is as follow. I have a C++ code that I haven't written and that I barely can modified. I am supposed to reflect this code in Python with boost. In the code, I have something looking like this:

Class A_Base { A_Base(){}; ~A_Base(){}; Whatever virtual and pure virtual functions; }

Class A_Derived{ A_Derived(Type1 arg1,...){whatever instructions;} ~A_Derived(){}; Whatever functions; }

Class B { B(A_Base& aBase, double& x){}; ~B(){}; Whatever functions; }

In the C++ main, at some point aDerived A_Derived is set, and then B(aDerived, x). I need to reflect that under python. Until now, I have been able, with a simple example, to reflect a function f, which is not a ctor, from a class B using A_Base& as argument type, but I can't figure out how to deal with it for a constructor. Based on:

http://wiki.python.org/moin/boost.python/ExportingClasses

I am declaring f under both its class B and A_Base as follow:

class_A_Base <A, boost::noncopyable>("A_Base", no_init) //this line can be modified .def("f", &B::f); class_B <B, boost::noncopyable>("B", init< >()) //this line can be modified .def("f", &B::f);

But when I try this for a constructor as f, it refuse to compile.

You don't wrap constructors the same way as functions (I don't think you can even take their address in C++). Instead, you use: .def(init<T1,T2,...>()) (where T1,T2,... are the argument types of the constructor), or do the same thing in the init argument to class_ itself (as I've done below). I think what you want is something like this (assuming A_Derived does actually inherit from A_Base, even though it doesn't in your example code): class_<A_Base,noncopyable>("A_Base", no_init); class_<A_Derived,bases<A_Base>,noncopyable>("A_Derived", no_init); class_<B,noncopyable>("B", init<A,double>()); Note that the float you pass in as "x" to B's constructor will not be modified in Python; that's unavoidable in this case. If that doesn't work, please post exactly what you're trying to compile; the example you posted has a few things that obviously won't compile, so it's hard to know exactly what the problem is. Good luck! Jim