Py++ and inner template classes

Can Py++ expose inner classes that come from templates?
I have code which is basically equivalent to the following:

class Outer {
public:
   template <typename T>
   class Inner {
   public:
     Inner(T);
   };
   typedef Inner<int> Inner_int;
   Inner_int f();
};

If I use the Py++ module_builder to create bindings for
the code, the class Inner_int is not exposed, and I get
the warning

WARNING: Outer::Inner<int> [class declaration]
 > execution error W1040: The declaration is unexposed,
but there are 
other declarations, which refer to it. This
 > could cause "no to_python converter found"
run time error. 
Declarations:   Outer::Inner<int> Outer::f() [member
 > function]
-- 
Pertti
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On Mon, Apr 28, 2008 at 3:58 PM, Pertti Kellomäki
<pertti.kellomakitut.fi> wrote:
> Can Py++ expose inner classes that come from
templates?
>  I have code which is basically equivalent to the
following:
>
>  class Outer {
>  public:
>   template <typename T>
>   class Inner {
>   public:
>     Inner(T);
>   };
>   typedef Inner<int> Inner_int;
>   Inner_int f();
>  };
>
>  If I use the Py++ module_builder to create bindings
for
>  the code, the class Inner_int is not exposed, and I
get
>  the warning
>
>  WARNING: Outer::Inner<int> [class declaration]
>  > execution error W1040: The declaration is
unexposed, but there are other
> declarations, which refer to it. This
>  > could cause "no to_python converter
found" run time error. Declarations:
> Outer::Inner<int> Outer::f() [member
>  > function]

I just created new test case and everything works fine:
http://pygccxml.svn.sourceforge.ne
t/viewvc/pygccxml?view=rev&revision=1315

I attached the generated code.

I guess you somehow excluded the class.

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

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Roman Yakovenko wrote:
> I just created new test case and everything works
fine:
> http://pygccxml.svn.sourceforge.ne
t/viewvc/pygccxml?view=rev&revision=1315

If you remove the body of function f in the test case, i.e.
instead of

   Inner_int f() { return Inner_int(23); }

just have

   Inner_int f();

then the exposing code is not generated. Should a file a
bug
in Bugzilla for this? Is there some short term workaround
to
force the exposing code to be generated?

Thanks,
-- 
Pertti
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On Tue, Apr 29, 2008 at 10:56 AM, Pertti Kellomäki
<pertti.kellomakitut.fi> wrote:
> Roman Yakovenko wrote:
>
> > I just created new test case and everything works
fine:
> > http://pygccxml.svn.sourceforge.ne
t/viewvc/pygccxml?view=rev&revision=1315
> >
>
>  If you remove the body of function f in the test case,
i.e.
>  instead of
>
>   Inner_int f() { return Inner_int(23); }
>
>  just have
>
>   Inner_int f();
>
>  then the exposing code is not generated. Should a file
a bug
>  in Bugzilla for this?

No 

> Is there some short term workaround to  force the
exposing code to be generated?

This should help:
http://language-binding.net/pyplusplus
/documentation/how_to/templates.html

Basically you have to instantiate that class, sizeof
operator does this.

-- 
Roman Yakovenko
C++ Python language binding
http://www.language-
binding.net/
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On Tue, Apr 29, 2008 at 3:35 PM, Pertti Kellomäki
<pertti.kellomakitut.fi> wrote:
> Roman Yakovenko wrote:
>
> > This should help:
> > http://language-binding.net/pyplusplus
/documentation/how_to/templates.html
> >
> > Basically you have to instantiate that class,
sizeof operator does this.
> >
>
>  One more thing. Is it possible to do this
non-invasively?

Yes

>I tried
>  to play around, but the only way I was able to get the
inner template
>  class exposed was to put the sizeof() somewhere in the
same header file
>  as the original class. I can do it if necessary, but I
would prefer
>  not to clutter the original header file if possible.

You can create another header file and instantiate the class
in it.
Then you can pass it to Py++. Take a look on this page:
http://www.language-binding.n
et/pyplusplus/documentation/how_to/best_practices.html

The short version: create header file, that belongs to
"bindings
project" and include all other files from it.
Instantiate the
templates within the file. Then pass this file to Py++.

HTH

-- 
Roman Yakovenko
C++ Python language binding
http://www.language-
binding.net/
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2008/4/30 Pertti Kellomäki <pertti.kellomakitut.fi>:
>  Not directly related to the inner class issue, but
maybe I am
>  not understanding something on the page correctly. It
says:
>
>  "Create one header file, which will include all
project header files."
>
>  However, when I do this, I do not get bindings for the
project
>  headers. I've attached a sample of files to show how I
attempt
>  to do it.

This is a known ( to me  ) issue:
http://language-binding.
net/pyplusplus/documentation/how_to/absolute_relative_paths.
html

> Or do you mean that one should create one big header
>  file by copying the contents of the headers into one
file? That
>  certainly works. I'm just not sure which one is meant
by the page.

I've got it right: single header file, that include all
others.


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