CODEWITHSUNDEEP
pythonc++vectorswig
Christina
Christina

Reputation: 333

Using SWIG to wrap C++ for Python. 'vector' not declared

I'm trying to wrap a C++ which creates a 3D vector so I can call it from Python and visualise the data. I'm trying to wrap with SWIG but when I do I get the error message

'vector’ was not declared in this scope

and having included "vector" into every file I can think of I'm not sure what I have to do to include it. I've created a set of very basic test functions to try to see where the problem is, it's roughly similar to the real code I'm trying to run.

test.cpp

#include <vector>
#include <iostream>
using namespace std;

vector<int> testfunction(vector <int>& value){
  cout <<"Running\n";
  return value;
}

test.h

#ifndef TEST_H_    // To make sure you don't declare the function more than once by including the header multiple times.
#define TEST_H_
#include <vector>
#include <iostream>

vector<int> testfunction(vector <int>& value);

test.i

/*test.i*/
%module test
%{
#include "test.h"
#include <vector>
%}

vector<double> testfunction(vector<double> value);

To compile I'm using the following

    g++ -g -ggdb -c -std=c++0x -I /include/python2.7 -o run test.cpp
    swig -c++ -python test.i
    gcc -fpic -c test.cpp test_wrap.cxx -I /include/python2.7
    gcc -shared test.o test_wrap.o -i _test.so

Can anyone tell me where I'm going wrong?

Upvotes: 4

Views: 1487

Answers (1)

Christina
Christina

Reputation: 333

I've found the answer to this problem and I'll post the updated code here. The problem was two fold:

  1. The example.i file for SWIG was wrong and crucially needed to include "std_vector.i"
  2. The compiling commands needed some more flags.

The following should compile and run.

example.h

    #ifndef TEST_H_
    #define TEST_H_
    #include <vector>
    #include <iostream>

    std::vector<int> testfunction(std::vector <int>& value);

    #endif

example.cpp

    #include <vector>
    #include <iostream>

    std::vector<int> testfunction(std::vector <int>& value){
      std::cout <<"Running\n";
      return value;
    }

example.i

%module example
%{
#include "example.h"
%}

%include "std_vector.i"
// Instantiate templates used by example
namespace std {
   %template(IntVector) vector<int>;
   %template(DoubleVector) vector<double>;
}

// Include the header file with above prototypes
%include "example.h"

makefile

all:

    g++ -g -ggdb -std=c++0x -I include/python2.7 -o run example.cpp example_run.cpp
    swig -c++ -python example.i

    gcc -fpic -c example.cpp example_wrap.cxx -I include/python2.7
    gcc -Wl,--gc-sections -fPIC -shared -lstdc++ example.o example_wrap.o -o _example.so

Python call:

>>> import example as ex
>>> iv=ex.IntVector(1)
>>> ex.testfunction(iv)

Happy Vectoring!

Upvotes: 3

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