[Pyrex] declear opaque type

[Michael JasonSmith]

On Fri, 2003-05-02 at 13:21, King C. Shu wrote:

> Anyway, you might consider to mention 'opaque' type or something
> similar in the above part of the guide. Sometime an opaque type 
> might not be a struct but just a typedef which users don't want
> to dig out off nested header files. :)
Done, with an example:
    http://ldots.org/pyrex-guide/4-functions.html#incomplete_types
As a result, I had to give a little discussion about passing NULL
    http://ldots.org/pyrex-guide/5-python-wrapper.html#NULL
but it is not biggie.

-- 
Michael JasonSmith      http://www.cosc.canterbury.ac.nz/~mpj17/