bump version to 12.2.2-pve1

[ceph.git] / ceph / src / boost / libs / python / doc / reference / manage_new_object.qbk

[section boost/python/manage_new_object.hpp]
[section Class `manage_new_object`]
`manage_new_object` is a model of [link concepts.resultconverter.resultconvertergenerator_concept ResultConverterGenerator] which can be used to wrap C++ functions which return a pointer to an object allocated with a new-expression, and expect the caller to take responsibility for deleting that object.
``
namespace boost { namespace python
{
    struct manage_new_object
    {
        template <class T> struct apply;
    };
}}
``
[endsect]
[section Class `manage_new_object` metafunctions]
``template <class T> struct apply``
[variablelist
[[Requires][`T` is `U*` for some `U`.]]
[[Returns][`typedef to_python_indirect<T> type;`]]
]
[endsect]
[section Example]
In C++:
``
#include <boost/python/module.hpp>
#include <boost/python/class.hpp>
#include <boost/python/manage_new_object.hpp>
#include <boost/python/return_value_policy.hpp>


struct Foo {
   Foo(int x) : x(x){}
   int get_x() { return x; }
   int x;
};

Foo* make_foo(int x) { return new Foo(x); }

// Wrapper code
using namespace boost::python;
BOOST_PYTHON_MODULE(my_module)
{
    def("make_foo", make_foo, return_value_policy<manage_new_object>())
    class_<Foo>("Foo")
        .def("get_x", &Foo::get_x)
        ;
}
``
Python code:
``
>>> from my_module import *
>>> f = make_foo(3)     # create a Foo object
>>> f.get_x()
3
``
[endsect]
[endsect]