[section boost/python/long.hpp]
[section Introduction]
Exposes a [link concepts.objectwrapper.typewrapper_concept_requirements TypeWrapper] for the Python [@http://www.python.org/doc/current/lib/typesnumeric.html long] integer type.
[endsect]
[section Class `long_`]
Exposes the [@http://www.python.org/doc/current/lib/typesnumeric.html numeric type protocol] of Python's built-in `long` type. The semantics of the constructors and member functions defined below can be fully understood by reading the [link concepts.objectwrapper.typewrapper_concept_requirements TypeWrapper] concept definition. Since `long_` is publicly derived from [link object_wrappers.boost_python_object_hpp.class_object `object`], the public `object` interface applies to `long_` instances as well.
``
namespace boost { namespace python
{
  class long_ : public object
  {
   public:
      long_(); // new long_

      template <class T>
      explicit long_(T const& rhs);

      template <class T, class U>
      long_(T const& rhs, U const& base);
  };
}}
``
[endsect]
[section Example]
``
namespace python = boost::python;

// compute a factorial without overflowing
python::long_ fact(long n)
{
   if (n == 0)
      return python::long_(1);
   else
      return n * fact(n - 1);
}
``
[endsect]
[endsect]