cross-platform c questions

[Gabriel Genellina]

En Wed, 14 Nov 2007 05:36:04 -0300, Martin v. Löwis <martin at v.loewis.de>  
escribió:

>> When writing a python c extension for needs to be compiled for
>> Windows,   Linux, and the Mac,
>> what cross-platform differences need to be  accounted for?#
>
> Not functions, no, but macros and typedefs. For example, there is
> now a typedef Py_ssize_t that you should use if you measure the
> number of bytes (or, more generally, things in a collection).

Is there any rules/criteria to decide when to use Py_ssize_t, int, or  
long? I've seen them somewhat mixed and don't know when exactly to use  
Py_ssize_t.

-- 
Gabriel Genellina