added 'construct_custodian_for' and test

include/boost/python/init.hpp

@@ -266,6 +266,15 @@ class init : public init_base<init<BOOST_PYTHON_OVERLOAD_ARGS> >
             policies, this->doc_string(), this->keywords());
     }
 
+    template <std::size_t ward>
+    init_with_call_policies<with_custodian_and_ward_postcall<1, ward+1>, self_t>
+    operator[](construct_custodian_for<ward> const&) const
+    {
+        typedef with_custodian_and_ward_postcall<1, ward+1> init_policy;
+        return init_with_call_policies<init_policy, self_t>(
+                   init_policy(), this->doc_string(), this->keywords());
+    }
+
     typedef detail::type_list<BOOST_PYTHON_OVERLOAD_ARGS> signature_;
 
     typedef detail::is_optional<

include/boost/python/with_custodian_and_ward.hpp

@@ -119,6 +119,49 @@ struct with_custodian_and_ward_postcall : BasePolicy_
     }
 };
 
+template <std::size_t ward>
+struct construct_custodian_for : default_call_policies
+{
+    BOOST_STATIC_ASSERT(ward > 0);
+
+    template <class ArgumentPackage>
+    static PyObject* postcall(ArgumentPackage const& args_, PyObject* result)
+    {
+        std::size_t arity_ = detail::arity(args_);
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+        if (ward > arity_ )
+#else
+        // check if ward exceeds the arity
+        // (this weird formulation avoids "always false" warnings
+        // for arity_ = 0)
+        if ( (std::max<std::size_t>)(0, ward) > arity_ )
+#endif
+        {
+            PyErr_SetString(
+                PyExc_IndexError
+              , "boost::python::construct_custodian_for: argument index out of range"
+            );
+            return 0;
+        }
+
+        PyObject* patient = detail::get_prev<ward>::execute(args_, result);
+        PyObject* nurse = detail::get_prev<1>::execute(args_.base);
+
+        if (nurse == 0) return 0;
+
+        result = default_call_policies::postcall(args_, result);
+        if (result == 0)
+            return 0;
+
+        if (python::objects::make_nurse_and_patient(nurse, patient) == 0)
+        {
+            Py_XDECREF(result);
+            return 0;
+        }
+        return result;
+    }
+};
+
 
 }} // namespace boost::python
 

test/test_pointer_adoption.cpp

@@ -8,6 +8,7 @@
 #include <boost/python/manage_new_object.hpp>
 #include <boost/python/return_internal_reference.hpp>
 #include <boost/python/class.hpp>
+#include <boost/python/make_constructor.hpp>
 
 using namespace boost::python;
 
@@ -86,6 +87,11 @@ A* as_A(Base* b)
     return dynamic_cast<A*>(b);
 }
 
+B* create_B(A* a)
+{
+    return new B(a);
+}
+
 BOOST_PYTHON_MODULE(test_pointer_adoption_ext)
 {
     def("num_a_instances", num_a_instances);
@@ -102,6 +108,8 @@ BOOST_PYTHON_MODULE(test_pointer_adoption_ext)
     class_<A, bases<Base> >("A", no_init)
         .def("content", &A::content)
         .def("get_inner", &A::get_inner, return_internal_reference<>())
+        .def("create_B", &create_B, with_custodian_and_ward_postcall<0,1,
+                                    return_value_policy<manage_new_object> >())
         ;
 
     class_<inner>("inner", no_init)
@@ -120,6 +128,16 @@ BOOST_PYTHON_MODULE(test_pointer_adoption_ext)
 
          .def("a_content", &B::a_content)
         ;
+
+    class_<B>("B1")
+        .def(init<A*>()[construct_custodian_for<1>()])
+        .def("a_content", &B::a_content)
+        ;
+
+    class_<B>("B2")
+        .def("__init__", make_constructor(&create_B, construct_custodian_for<1>()))
+        .def("a_content", &B::a_content)
+        ;
 }
 
 #include "module_tail.cpp"

test/test_pointer_adoption.py

@@ -3,14 +3,16 @@
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 """
 >>> from test_pointer_adoption_ext import *
+>>> import sys
 
 >>> num_a_instances()
 0
 
 >>> a = create('dynamically allocated')
 >>> num_a_instances()
 1
-
+>>> sys.getrefcount(a)
+2
 >>> a.content()
 'dynamically allocated'
 
@@ -55,13 +57,71 @@
 Test call policies for constructors here
 
 >>> a = create('second a')
+>>> a.content()
+'second a'
+>>> num_a_instances()
+1
+>>> b = a.create_B()
+>>> num_a_instances()
+1
+>>> sys.getrefcount(a)
+3
+>>> b.a_content()
+'second a'
+>>> b = None
 >>> num_a_instances()
 1
+>>> sys.getrefcount(a)
+2
+
 >>> b = B(a)
 >>> num_a_instances()
 1
+>>> sys.getrefcount(a)
+3
+>>> a.content()
+'second a'
+>>> b.a_content()
+'second a'
+>>> b = None
+>>> num_a_instances()
+1
+>>> sys.getrefcount(a)
+2
+
+>>> b = B1(a)
+>>> num_a_instances()
+1
+>>> sys.getrefcount(a)
+3
+>>> a.content()
+'second a'
+>>> b.a_content()
+'second a'
+>>> b = None
+>>> num_a_instances()
+1
+>>> sys.getrefcount(a)
+2
+
+>>> b = B2(a)
+>>> num_a_instances()
+1
+>>> sys.getrefcount(a)
+3
 >>> a.content()
 'second a'
+>>> b.a_content()
+'second a'
+>>> b = None
+>>> num_a_instances()
+1
+>>> sys.getrefcount(a)
+2
+
+>>> b = B(a)
+>>> num_a_instances()
+1
 
 >>> del a
 >>> num_a_instances()