[Cython] Automatic C++ conversions

[Robert Bradshaw]

On Mon, Jul 2, 2012 at 5:49 AM, Sturla Molden <sturla at molden.no> wrote:
> On 30.06.2012 01:06, Stefan Behnel wrote:
>
>>> std::string<=>  bytes
>>> std::map<=>  dict
>>> iterable =>  std::vector =>  list
>>> iterable =>  std::list =>  list
>>> iterable =>  std::set =>  set
>>> 2-iterable =>  std::pair =>  2-tuple
>>
>>
>> Very cool.
>
>
> I think (in C++11) std::unordered_set and std::unordered_map should be used
> instead. They are hash-based with O(1) lookup.
>
> std::set and std::map are binary search threes with average O(log n) lookup
> and worst-case O(n**2).
>
> Also beware that C++11 has a std:tuple type.

The object => C++ coercion is always explicit, there's no choice made
here. This is used to do, e.g.

    cdef map<int, vector<double>> my_cpp_map = o

or

    cdef extern from "mylibrary.h":
        cdef map<long, double> my_func(vector<long>)

    def f(o):
        return my_func(o)

It would make sense to support these unordered versions as well, and
fairly straightforward.

- Robert