SWIG error for boost::posix_time::ptime conversion - swig

Question

I am warping a very simple C++ class by using SWIG.
The boost ptime is used in that C++ class.
When I try to execute command
swig -c++ -python example.i
There is an error:
example.h:7: Warning 315: Nothing known about 'boost::posix_time::ptime'.
example.h:7: Warning 315: Nothing known about 'boost::posix_time::ptime'.
How can I resolve this problem?
The example.i file is:
//File: example.i
%module example
%{
#define SWIG_FILE_WITH_INIT
#include <boost/date_time/posix_time/ptime.hpp>
#include "example.h"
%}
// for std:string
%include "std_string.i"
// for vector
%include "std_vector.i"
%include stl.i
%include "example.h"
The example.h file is:
#pragma once
#include <string>
#include <boost/date_time/posix_time/ptime.hpp>
using std::string;
using boost::posix_time::ptime;
class Example{
public:
Example(string name, ptime timestamp){
// doSomething...
}
};

Answer 1

Solved by friend Mike and me.
The correct interface file is as following (without mentioning boost header):
/* File: example.i */
%module example
%{
#define SWIG_FILE_WITH_INIT
#include "example.h"
%}
%include "example.h"
The swig execution command is (OSX):
swig -c++ -python example.i
g++ -O2 -fPIC -c example.h -std=c++11
g++ -O2 -fPIC -c example_wrap.cxx -I/Library/anaconda2/include/python2.7
g++ -bundle -flat_namespace -undefined suppress -o _example.so *.o
The swig execution command is (Ubuntu 14.04):
swig -c++ -python example.i
g++ -O2 -fPIC -c example.h -std=c++11
g++ -O2 -fPIC -c example_wrap.cxx -I/usr/include/python2.7
g++ -shared -o _example.so *.o
Only change the last line.