[C++-sig] to_python converter and make_getter

[Michael Wild]

[re-post with the correct from-address, the original got rejected]

On 01/23/2013 07:08 PM, Michael Wild wrote:
> On 01/23/2013 07:03 PM, Jim Bosch wrote:
>> On 01/23/2013 12:56 PM, Michael Wild wrote:
>>
>> <snip>
>>
>>>
>>> Yes, I thought of that too. While this "solves" this case (it certainly
>>> is not very discoverable for future maintainers), it does not help in
>>> the case of container support. Say I wanted to expose
>>> std::vector<QString> (or std::vector<ustom_string> from the Boost.Python
>>> FAQ, for that matter) using the boost::python::vector_indexing_suite. I
>>> am perfectly able to create such a list, I can append items, the only
>>> thing I can't do is *retrieving* them. It's like a black hole for data
>>> ;-)
>>>
>>
>> I'm afraid the vector_indexing_suite is some black magic I'm not
>> terribly familiar with.  But I do know that in some contexts it returns
>> proxy objects in order to allow setting and safer lifetime management,
>> and I suspect that's what is not playing nicely with your custom
>> converters.  Or have you investigated that further and determined that
>> it's calling make_getter, and that's why you're focused on that?
> 
> Not at all, I just stumbled across this problem a little later than the
> one with the make_getter. Somehow I suspect that if I can teach bp to
> properly return by value, both cases would be resolved automagically.
> After all, things work smoothly for std::string.
> 
> Michael
> 

About the indexing_suite: By setting the NoProxy template argument to
true, the custom string is being converted correctly, leaving me only
with make_getter to be dealt with. For now I think I'll go with
explicitly specializing make_getter. AFAIK this does no harm and
automagically fixes class_::add_property() and friends.

Thanks for all the input.

Michael