How to expose...

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static class data members

object x_class 
    = class_<X>("X") 
         .def( ... ) 
         ... 
         ; 
 
x_class.attr("fu") = X::fu; 
x_class.attr("bar") = X::bar; 
... 

Since version 1.30 you can use class_ method:

   .add_static_property("name", &fget [,&fset])

static class functions

It's likely to be in 1.30 release.

Meanwhile you should do something which mirrors pure Python:

class foo(object):
    def f(x,y):
        return x*y
    f = staticmethod(f)

So in C++, it would be something like:

    class_<foo>("foo")
        .def("f", &foo::f)
        .staticmethod("f")  // **
        ;

Where the marked line would be implemented something like this:

self& staticmethod(char const* name)
{
    dict d(handle<>(borrowed(downcast<PyTypeObject>(this->ptr())->tp_dict))); 
    object method = (object)(d[name]); 
    this->attr(name) = object(handle<>(
         PyStaticMethod_New( callable_check(method.ptr()) ) 
      ));
    return *this;
}

To create overloaded staticmethods in python, you overload first, then you make it static.

module level objects

at module creation time

First, create those objects like

object class_X = class_<X>("X");
object x = class_X();

Second, expose them:

scope().attr("x") = x; // injects x into current scope

By default current scope is module.

at run-time

Use a function:

template <class T>
void set(const std::string& name, const T& value) {
  interpreter()->mainmodule()[name] = value;
}

Note:: interpreter() is to be added about now. Date

mutable C++ object

Perhaps you'd like the resulting Python object to contain a raw pointer to the argument? In that case, the caveat is that if the lifetime of the C++ object ends before that of the Python object, that pointer will dangle and using the Python object may cause a crash.

There is a way to do that, but it's more convoluted than it should be:

  template <class T>
  T& identity(T& x)
  {
      return x;
  }

  template <class T>
  object get_object_reference(T& x)
  {
      // build a function object around identity
      object f
          = make_function(
                  &identity<T>, return_value_policy<reference_existing_object>());

      // and call
      return f(x);
  }

std::C++ container

You can always wrap the container with class_ directive. For example for std::map:

template<class Key, class Val>
struct map_item
{
    typedef std::map<Key,Val> Map;

    static Val& get(Map const& self, const Key idx) {
      if( self.find(idx) != self.end() ) return self[idx];
      PyErr_SetString(PyExc_KeyError,"Map key not found");
      throw_error_already_set();
    }

    static void set(Map& self, const Key idx, const Val val) { self[idx]=val; }

    static void del(Map& self, const Key n) { self.erase(n); }

    static bool in(Map const& self, const Key n) { return self.find(n) != self.end(); }

    static list keys(Map const& self)
    {
        list t;
        for(Map::const_iterator it=self.begin(); it!=self.end(); ++it)
            t.append(it->first);
        return t;
    }
    static list values(Map const& self)
    {
        list t;
        for(Map::const_iterator it=self.begin(); it!=self.end(); ++it)
            t.append(it->second);
        return t;
    }
    static list items(Map const& self)
    {
        list t;
        for(Map::const_iterator it=self.begin(); it!=self.end(); ++it)
            t.append( make_tuple(it->first, it->second) );
        return t;
    }
}

using namespace boost::python;
typedef std::map<Key,Val> Map;
class_<Map>("Map")
  .def("__len__", &Map::size)
  .def("__getitem__", &map_item<Key,Val>().get, return_value_policy<copy_non_const_reference>() )
  .def("__setitem__", &map_item<Key,Val>().set)
  .def("__delitem__", &map_item<Key,Val>().del)
  .def("clear", &Map::clear)
  .def("__contains__", &map_item<Key,Val>().in)
  .def("has_key", &map_item<Key,Val>().in)
  .def("keys", &map_item<Key,Val>().keys)
  .def("values", &map_item<Key,Val>().values)
  .def("items", &map_item<Key,Val>().items)
  ;

"Raw" function

I want to write in python:

•     def function( *args ):
          # Mess arount with elements of args.

You can make one with the library's implementation details. Be warned that these interfaces may change, but hopefully we'll have an "official" interface for what you want to do by then.

python::objects::function_object(
    f                       // must be py_function compatible
    , 0, std::numeric_limits<unsigned>::max()  // arity range
    , python::detail::keyword_range());        // no keywords

will create a Python callable object.

f is any function pointer, function reference, or function object which can be invoked with two PyObject* arguments and returns something convertible to a PyObject*.

You can add this to your module namespace with:

scope().attr("name") = function_object(f, ... );

Now you can also

class_<foo>("foo")
    .def("bar",function_object(f, ... ) );

aswell, but not

function_object bar(f, ... );
...
class_<foo>("foo")
    .def("bar",bar);

because function_object is a function, not a class.

getter and setter methods as a property

Suppose you have class "C" with methods "getA" and "setA" and you want to expose them as a property "a". It's not a problem with  .add_property("a", &C::getA, &C::setA) unless you need to assign ../CallPolicy to them. In that case use "make_function": {{{ .add_property("a",

• make_function(&C::getA, return_value_policy<...>()), make_function(&C::setA, with_custodian_and_ward<...>())}}}