[Cython] IFDEF in cython ?

[Stefan Behnel]

Hi,

David Cournapeau wrote:
> I would like to know whether adding an IFDEF-like feature in cython
> would be feasible ? I would like to define some cython code depending
> on some defines in the header of the library I am wrapping.

You can use a separate .h file and do something like this

    #ifdef SOME_EXTERNAL_DEFINE
    #  define MYVAL 1
    #else
    #  define MYVAL 0
    #endif

then you can write this:

    cdef extern from "myheader.h":
         cdef int SOMETHING

    if SOMETHING:
        print "ON"
    else:
        print OFF

and the C compiler will do the right thing.

I wouldn't mind making this a general Cython feature, though. Maybe
something like

    if cython.defined(SOME_NAME):
         ...

would work.

Stefan