[C++-sig] BPL and Py_Clear()

[David Abrahams]

"Niall Douglas" <s_sourceforge at nedprod.com> writes:

> On 14 Jun 2005 at 9:01, David Abrahams wrote:
>
>> >> >> > Why doesn't BPL's ptr() accept pointers to integral types?
>> >> >> 
>> >> >> Think about how you would implement such a thing.  What would a
>> >> >> an overriden virtual function written in Python see?
>> >> >
>> >> > A single item of whatever type eg; long * would mean the python
>> >> > code sees a python integer.
>> >> 
>> >> I'm confused now.  If you pass an int* without wrapping it in ptr()
>> >> that's exactly what happens, right?
>> >
>> > I don't know about int, but unsigned int * yields a runtime error of
>> > no to-python converter for unsigned int.
>> 
>> Oh, drat.  But then, why not just dereference the pointer and pass
>> that?
>
> Because I want to pass the pointer, not what it points to. 

I don't get it.  If you expect the Python code to just see a Python
int, what's the advantage in passing a pointer?  You are aware that
Python ints are immutable, I presume!

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com