[Pyrex] Wrapping "typedef struct _A A;", third pass

[Edward C. Jones]

The following works. But if it is the best way of doing things, Pyrex 
has a wart. The declaration

     cdef struct _A:
         double big_lie

below doesn't seem to be needed except to turn off an error message 
about incomplete types. Looking at "wrapper.c", I see essentially

     static struct _A __pyx_v_a;
     PyObject *__pyx_1 = 0;
     __pyx_v_a = make(7);
     __pyx_1 = PyInt_FromLong(get(__pyx_v_a));
     __Pyx_PrintItem(__pyx_1)

Can Pyrex know that it doesn't care how _A is defined as long as it is a 
struct? Perhaps:

     cdef struct _A:
         pass
     ctypedef _A A

because in C "typedef struct _A A;" is _syntactically_ similar to
"typedef struct _A {} A;".

----------------
mystery.h:

struct _A {
     int i;
};

----------------
tds.h:

#include "mystery.h"

typedef struct _A A;

A make(int i);
int get(A a);

----------------
tds.c:

#include "tds.h"

A make(int i)
{
     A a;
     a.i = 7;
     return a;
}

int get(A a)
{
     return a.i;
}

----------------
wrapped.pyx:

cdef extern from "tds.h":
     cdef struct _A:
         double big_lie
     ctypedef _A A

     A make(int i)
     int get(A a)

cdef A a
a = make(7)
print get(a)

----------------
test.py:

#! /usr/bin/env python

import wrapped

----------------
somake:

if pyrexc wrapped.pyx
then {
     if gcc -c -fPIC -I/usr/include/python2.2/ wrapped.c
     then {
         gcc -c -fPIC tds.c;
         gcc -shared tds.o wrapped.o -o wrapped.so;
     } fi;
} fi;