[Python] I cannot get swig to apply a basic typemap when mapping a python list to a pointer to...

I'm trying to create a python interface for a larger project but as I kept running into this issue I decided to rtfm and do a minimal example. Turns out that I run into the same issue both on windows and on linux so there's obviously something I don't understand here. These are the files:

// example.c

#include <math.h>
#include "example.h"

double rms(double* seq, int n) {
double sum = 0.0;
for (int i = 0; i < n; i++) {
sum += seq * seq;
}
return sqrt(sum / n);
}


// example.h


#ifndef EXAMPLE_H
#define EXAMPLE_H

double rms(double* seq, int n);

#endif


// example.i

%module example

%include "typemaps.i"

%{
#include "example.h"
%}

%apply (double *IN_ARRAY1, int DIM1) { (double *seq, int n) };


%include "example.h"


Running swig -python example.i consistently gives me

Warning 453: Can't apply (double *IN_ARRAY1,int DIM1). No typemaps are defined.


The examples that do work are simple examples from the SWIG website without typemaps:

int fact(int n);

int my_mod(int x, int y);

char *get_time();


Structs also work fine in my larger project.

I confirmed that typemaps.i is available to swig (by introducing a typo such as 'trmpaps.i') and observing that it complains.

I did some tests with numpy.i with similar results but don't want to introduce more confusion to this question.

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