building shared library from D code to import into cython

[Ellery Newcomer via Digitalmars-d-learn]

On Sunday, 12 October 2014 at 16:07:19 UTC, Laeeth Isharc wrote:
> Any thoughts on speed in 2014  of pyd vs using cython to talk 
> to D directly via C/C++ interface?  I saw this old coment here:
>

pyd is basically just a convenience layer on top of the C 
interface. The part that would most likely screw with performance 
would be conversion from D objects to python objects and vice 
versa since that normally does a value copy. At the time of that 
comment, pyd's strategy for arrays was just iterate and convert 
each element. Now pyd can take advantage of the buffer protocol 
if it is exposed (2.7+), so converting e.g. numpy arrays should 
be just a memcopy.

If you want by ref semantics instead of by value, use PydObject 
instead of a D type in your function signature. You can also turn 
off all conveniences and just use the C api with raw_only 
(https://bitbucket.org/ariovistus/pyd/wiki/CeleriD)