Re: [pygccxml-development] FT - open issues

[Matthias B. <ba...@ir...>]

Roman Yakovenko wrote:
>> > 3. transformers index argument from 1 and not from zero. I think we
>> > need to discuss
>> >     this one more time. I don't agree with this interface. This is
>> > tooooo confusing.
>>
>> Here's a piece of code from the Boost.Python tutorial:
>>
>> def("f", f,
>>      return_internal_reference<1,
>>          with_custodian_and_ward<1, 2> >());
>>
>> The numbers 1 and 2 refer to the first and second argument. So I would
>> find it confusing if Py++ would do it otherwise.
>>
>> Besides that, I've reserved the index 0 to represent the return value.
> 
> Because 0 represents self ( this ). 

Well, you say yourself that 0 does not represent the first value from
the argument list. So what's your point? (by the way, the above code
refers to a free function so there is no self/this)

If the function transformers would be 0-based it could happen that one
and the same argument has to be referred to by two different values,
depending on the context. If the user applies a function transformer he
would have to use the index 0 for the first argument whereas if he also
applies a call policy he would have to use the index 1 for the very same
argument. This is inconsistent.

>> > 4. Base class for all transformations should be introduced.
>>
>> There is one already: function_transformer_t
>> You may certainly derive from that class if you wish, it's just that you
>> don't have to (because this class just defines/documents the interface
>> and doesn't contain any actual code).
> 
> Where is the code that decides what method should be called and what not?

I'm not sure what "decision" you are referring to, but the methods are
called in the substitution_manager_t class.

- Matthias -