Re: [pygccxml-development] Template constructors

[Roman Y. <rom...@gm...>]

On Sun, Mar 16, 2008 at 11:08 PM, Matthias Baas <mat...@gm...> wrote:
> Hi,

Hello. Welcome back.

>  after being away from the "wrapping business" for quite a while I'm now
>  back and trying to wrap another library that is heavily template based.
>  As I'm starting from scratch, I'm now using the official module builder
>  instead of my own version.
>  So as a first general question, is there meanwhile some special support
>  for templates? Can I tell Py++ what template arguments to use and it
>  takes care of instantiating it?
>  I'm assuming that's not (yet) the case, so I was instantiating the stuff
>  myself.
>  But I ran into a problem with a template constructor inside a template
>  class. I could only wrap the non-template constructors whereas the other
>  ones don't seem to be reported by gccxml.
>  Here is an example:
>
>  ///////////////////// File: header.h
>  template<class T>
>  class Spam
>  {
>    T x;
>    T y;
>    public:
>
>    Spam() : x(0),y(0) {}
>    template<class V>
>    Spam(V a, V b) : x(a),y(b) {}
>  };
>
>  // Instantiate the template
>  inline void dummy()
>  {
>    Spam<double> c0(1, 2);
>  }
>
>  ####################### File: generate.py
>
>  from pyplusplus.module_builder import module_builder_t
>
>  mb = module_builder_t(files = ['header.h'])
>
>  spam = mb.class_("Spam<double>")
>  spam.include()
>
>  # Print all declarations that are available on the class
>  decls = spam.decls()
>  for decl in decls:
>      print decl
>
>  mb.build_code_creator(module_name="spammod")
>  mb.split_module(dir_name="bindings")
>
>
>  When I run the Python script, the declarations that get printed are the
>  following:
>
>  Spam<double>::Spam(Spam<double> const & arg0) [copy constructor]
>  Spam<double>::Spam() [constructor]
>  Spam<double>::x [variable]
>  Spam<double>::y [variable]
>
>  I would also have expected a constructor that takes two ints, but it
>  isn't there and so it isn't wrapped. Is there another way to instantiate
>  the class that would make the constructor visible?

Matthias unfortunately the problem is on the GCCXML side

I don't see any work around to the problem :-(. It seems that template
constructors of template class is a special case, that GCCXML
could\does not treat.

I think the best solution in this case is to add "constructor
declaration" to the classes.


-- 
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/