Boost C++ Libraries

libs/python/test/properties.cpp

// Copyright David Abrahams 2004. Distributed under the Boost
// Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#include <boost/python.hpp>

using namespace boost::python;

namespace test {

// Hmm.  return_internal_reference<>() wants to wrap a real class.
class ret_type
{
 public:
    ret_type() : i(42.5) {}
    double i;
};

class crash_me
{
    private:
        ret_type i;
    public:
        ret_type& get_i() { return i; }
};

}

struct X
{
    X( int value ) : m_value( value )
    { ++s_count; }
    
    X( const X &other ) : m_value( other.m_value )
    { ++s_count; }
    
    ~X() 
    { --s_count; }
        
    int get_value() const
    { return m_value; }
    
    void set_value(int new_value)
    { m_value = new_value; }
    
    static int get_instance_count()
    { return s_count; }
        
    int m_value;

    static int s_count;
};

int X::s_count = 0;

int get_X_instance_count()
{ return X::get_instance_count(); }



BOOST_PYTHON_MODULE(properties_ext)
{
    typedef return_value_policy<return_by_value> return_by_value_t;
    typedef return_internal_reference<> return_by_internal_reference_t;
    class_<X>("X", init<int>() )
        //defining read only property
        .add_property( "value_r", &X::get_value )
        //defining read \ write property 
        .add_property( "value_rw", &X::get_value, &X::set_value )
        //defining read \ write property using make_getter and make_setter
        .add_property( "value_direct", 
                        make_getter( &X::m_value, return_by_value_t() ),
                        make_setter( &X::m_value, return_by_internal_reference_t() ) )
        //defining read only property for static member
        .add_static_property( "instance_count", &X::get_instance_count )
        //defining read \ write property for static member using make_getter and make_setter
        .add_static_property( "instance_count_direct", 
                              make_getter( &X::s_count, return_by_value_t() ), 
                              make_setter( &X::s_count, return_by_internal_reference_t() ) )
        //defining class property using a global function
        .add_static_property( "instance_count_injected", &get_X_instance_count );

    
    class_< test::ret_type>( "ret_type")
        .add_property( "i", &test::ret_type::i, &test::ret_type::i)
        ;
    
    class_< test::crash_me> crash_me_wrapper( "crash_me");
    
    crash_me_wrapper
        .def( "get_i", &test::crash_me::get_i , return_internal_reference<>())
        ;
    
    crash_me_wrapper.add_property( "i", crash_me_wrapper.attr("get_i"));

}

#include "module_tail.cpp"