[Cython] Type inference and C++

[Vitja Makarov]

2012/7/24 Stefan Behnel <stefan_ml at behnel.de>:
> Vitja Makarov, 24.07.2012 14:48:
>> 2012/7/24 Stefan Behnel:
>>> Stefan Behnel, 24.07.2012 12:43:
>>>> Vitja Makarov, 23.07.2012 07:13:
>>>>> Here is part of original testcase:
>>>>>
>>>>> from cython.operator cimport dereference as d
>>>>> from cython.operator cimport preincrement as incr
>>>>> from libcpp.vector cimport vector
>>>>>
>>>>> def reverse_iteration_test(L):
>>>>>     v = new vector[int]()
>>>>>     for a in L:
>>>>>         v.push_back(a)
>>>>>     it = v.rbegin()
>>>>>     while it != v.rend():
>>>>>         a = d(it)
>>>>>         incr(it)
>>>>>         print(a)
>>>>>
>>>>> I think it's not correct to infer `a` as reverse_iterator because it's
>>>>> not an iterator it's vector's item.
>>>>
>>>> Right. DereferenceNode should implement infer_type().
>>>
>>> ... and not only DereferenceNode. Pretty much all C++ operators do not
>>> properly implement type inference. I'll take a look.
>>
>> Ok, thanks!
>
> Here's my fix.
>
> https://github.com/cython/cython/commit/43f3d87d9760d3c7e7fa6a127d0bdaf549880621
>
> It became a bit more involved than I had anticipated, including some
> cleanups and fixes for a couple of quirks that I ran into.
>
> It's really too bad that the Sage build is currently broken. The C++ code
> in there would be a good exercise for this change (even if it won't benefit
> from the type inference). At least, so far, it doesn't seem like it has
> broken more than what was broken before.
>

And sorry for stupid question: do we support multiple overloaded
operators of the same kind?


-- 
vitja.