Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Boost.Python - <boost/python/copy_const_reference.hpp>

Boost.Python

Header

Contents

Classes
Class copy_const_reference
Class copy_const_reference synopsis
Class copy_const_reference metafunctions
Example

Classes

Class copy_const_reference

copy_const_reference is a model of ResultConverterGenerator which can be used to wrap C++ functions returning a reference-to-const type such that the referenced value is copied into a new Python object.

Class copy_const_reference synopsis

namespace boost { namespace python
{
    struct copy_const_reference
    {
        template  struct apply;
    };
}}

Class copy_const_reference metafunctions

template  struct apply
Requires: T is U const& for some U.
Returns: typedef to_python_value type;

Example

C++ Module Definition

#include 
#include 
#include 
#include 

// classes to wrap
struct Bar { int x; }

struct Foo {
   Foo(int x) : { b.x = x; }
   Bar const& get_bar() const { return b; }
 private:
   Bar b;
};

// Wrapper code
using namespace boost::python;
BOOST_PYTHON_MODULE(my_module)
{
    class_("Bar");

     class_("Foo", init())
        .def("get_bar", &Foo::get_bar
            , return_value_policy())
       ;
}

Python Code

>>> from my_module import *
>>> f = Foo(3)         # create a Foo object
>>> b = f.get_bar()    # make a copy of the internal Bar object

Revised 13 November, 2002

© Copyright Dave Abrahams 2002.