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

[David Abrahams]

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

> On 15 Jun 2005 at 11:47, David Abrahams wrote:
>
>> >> >> 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!
>
> Because if my C++ is going through a BPL wrapped virtual function and 
> is passing it an array of unsigned int, if python doesn't overload it 
> then it goes C++=>Python=>C++ and no extra action is required.

Not if you use the new-style polymorphism support.

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