using stdint with swig and numpy.i

Question

I'm developing a module for using c inline in Python code based on swig. For that I would like to make numpy arrays accessible in C. Until now I used C types like unsigned short but I would like to use types like uint16_t from stdint.h to be save whatever compiler my module encounters.

Unfortunately the c++-functions do not get wrapped correctly when using stdint.htypes. The Error given is: _setc() takes exactly 2 arguments (1 given). That means, the function is not wrapped to accept numpy arrays. The error does not occur, when I use e.g. unsigned short.

Do you have any ideas, how I can make swig map numpy arrays into stdint-types?

interface.i NOT working:

/* interface.i */
extern int __g();
%}
%include "stdint.i"
%include "numpy.i"

%init %{
import_array();
%}
%apply (uint16_t* INPLACE_ARRAY3, int DIM1) {(uint16_t* seq, int n1)};
extern int __g();

c++ function NOT working:

#include "Python.h"
#include <stdio.h>
#include <stdint.h>
extern uint16_t* c;
extern int Dc;
extern int Nc[4];
void _setc(uint16_t *seq, int n1, int n2, int n3)
{
    c = seq;
    Nc[0] = n1;
    Nc[1] = n2;
    Nc[2] = n3;
}

interface.i working:

/* interface.i */
extern int __g();
%}
%include "stdint.i"
%include "numpy.i"

%init %{
import_array();
%}
%apply (unsigned short* INPLACE_ARRAY3, int DIM1) {(unsigned short* seq, int n1)};
extern int __g();

c++ function working:

#include "Python.h"
#include <stdio.h>
#include <stdint.h>
extern unsigned short* c;
extern int Dc;
extern int Nc[4];
void _setc(unsigned short *seq, int n1, int n2, int n3)
{
    c = seq;
    Nc[0] = n1;
    Nc[1] = n2;
    Nc[2] = n3;
}

jochen · Accepted Answer · 2015-12-16T16:44:14.483

Haha, I found some "solution" just a few minutes after I gave up and posted this question.

I edited the numpy.ito fit my cause: I substituted the old C types with stdint.h types in lines 3044 ff:

[..]
/* Concrete instances of the %numpy_typemaps() macro: Each invocation
 * below applies all of the typemaps above to the specified data type.
 */
%numpy_typemaps(int8_t       , NPY_BYTE     , int)
%numpy_typemaps(uint8_t     , NPY_UBYTE    , int)
%numpy_typemaps(int16_t             , NPY_SHORT    , int)
%numpy_typemaps(uint16_t    , NPY_USHORT   , int)
%numpy_typemaps(int32_t               , NPY_INT      , int)
%numpy_typemaps(uint32_t      , NPY_UINT     , int)
%numpy_typemaps(long              , NPY_LONG     , int)
%numpy_typemaps(unsigned long     , NPY_ULONG    , int)
%numpy_typemaps(int64_t         , NPY_LONGLONG , int)
%numpy_typemaps(uint64_t, NPY_ULONGLONG, int)
%numpy_typemaps(float             , NPY_FLOAT    , int)
%numpy_typemaps(double            , NPY_DOUBLE   , int)
[..]

I wonder if anyone has a better idea than editing the numpy.i

Cheers Jochen

Whoa +1. I think the correct solution is to file a bug report, but I don't know if it will fall on deft ears. I actually ended up using ``` %apply (unsigned char *IN_ARRAY1, int DIM1) {(uint8_t * buff_ptr, int buff_size)} ``` — hmaarrfk, Jan 12 '18 at 01:16

using stdint with swig and numpy.i

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