[C++-sig] Limit On No. Of Constructors?

gideon may gideon at computer.org
Thu Nov 14 19:50:10 CET 2002

I am not Dave ;)
but I've come across the same problem.

--On Thursday, November 14, 2002 10:48 AM -0500 "Scott A. Smith" 
<ssmith at magnet.fsu.edu> wrote:

> Hi Dave,

> perhaps even OSX). But for now, I am hoping you can clarify your
> statements on how to deal with the vc6 problem.
> 1.) When I declare a class:
>   class_<MyClass>("MyClass", init<>())
>    ... class constructors and functions
>   ;
>    it would seem that all .def() calls for the class must reside before
>    the semi-colon used for the class end. Hence, I don't see how I can
> move any
>    of these into a separate file.  I have no problems moving entire
> classes    into individual files. I don't understand how I can use a
> class_<MyClass>&
>    parameter in a different file then continue putting in .def() calls
> that    are part of the class MyClass. Could you give me a brief example?

The def method of class_ returns a reference to the class object. This 
chaining of the method calls.
To split the def calls over multiple functions you can do something like :

void second_definition(class_<MyClass> & my_class)
        .def("method2", &MyClass::method2)


void first_definition()
    class_<MyClass> my_class("MyClass")
	.def("method1", &MyClass::method1)

> 2.) Is it possible to blend modules. That is, make a Python module that
> has     class A, one that has class B, then somehow blend the two into a
> single     module. Then only the summed moduled is imported into Python
> rather than     all of the individual ones?
> 3.) I keep all my BP functions in separate files, except those functions
> that
>     needed to be part of a class (e.g. for weak wrapping using V1). I have
>     always done this using header files, so the structure of my code is
> quite
>     different from all of the tutorial examples. I am wondering if, for
> whatever
>     reasons, I should be keeping my BP functions in (.cpp) files instead?
>     Currenty I have a single header file that contains, among other
> things,
>       {
>#     include <FileA.h>
>#     include <FileB.h>
> .
> .
>       }
>     Is there a better, or more standardized, way of organizing my code
> while     keeping what is related to BP largely away from what is my
> project's     usual C++ code?

Why not something like this :

FileA_impl.cpp ====================================

#include <FileA.h>

void ClassA_impl()
    class_<ClassA> class_a("ClassA")

FileB_impl.cpp =====================================

#include <FileB.h>

void ClassB_impl()
    class_<ClassB> class_b("ClassB")

FileWrapper.cpp ===============================

void ClassA_impl();
void ClassB_impl();



This way you have a nice separation between the
class wrapper implementations.



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