Boost documentation.

[Jacek Generowicz]

Jacek Generowicz <jmg at ecs.soton.ac.uk> writes:

> Are there any sources of documentation for the Boost Python Library
> besides the source examples, getting_started<1-5>.cpp ?
> 
> How would I write a C++ function which receives a python list and
> converts it into a std::vector<int> for its own use ?
> 
> Thanks,
> 
> Jacek

Well, I've managed to get an attempt past the compiler now, so I'll
post it here for a critique.

It provides one function called `hmm', which takes a tuple (of
integers), and should print out those integers. Unfortunately it
thinks all the integers are zero (though it does get the correct
number of them).

When I try to do something similar with lists rather than tuples, the
get() method appears to be unavailable.

BTW, I'm using gcc version 2.95.2 on linux.
--------------------------------------------------------------
#include <vector>
#include <iterator>
#include <algorithm>

#include <boost/python/class_builder.hpp>
namespace python = boost::python;

namespace {
  void hmm( std::vector<int> v ) {
    std::copy( v.begin(), v.end(), std::ostream_iterator<int>( std::cout, " " ) );
    std::cout << std::endl;
  }
}

BOOST_PYTHON_BEGIN_CONVERSION_NAMESPACE

std::vector<int> from_python( PyObject * p, python::type< std::vector<int> > ) {
  python::tuple tup
    = python::tuple(python::ref(p, python::ref::increment_count));
  std::vector<int> v( tup.size() );
  for ( int i; i<tup.size(); i++ ) {
    int j = from_python( tup[i].get(), python::type<int>() ); 
    std::cout << j << std::endl;
    v[i] = j;
  }
  return v;
}

BOOST_PYTHON_END_CONVERSION_NAMESPACE

BOOST_PYTHON_MODULE_INIT(converting)
{
  try
  {
    python::module_builder this_module("converting");
    this_module.def( hmm, "hmm" );
  }
  catch(...)
  {
    python::handle_exception();
  }
}