CallPolicy allows boost.python to deal with raw references and pointers. Different policies specifies different strategies of managing object ownership.

TableOfContents

with_custodian_and_ward

ties lifetimes of the arguments

with_custodian_and_ward_postcall

ties lifetimes of the arguments and results

return_internal_reference

ties lifetime of one argument to that of result keep the owning object alive as long as the owned objects are also alive.

return_value_policy<T>

with T one of:

reference_existing_object

naïve (dangerous) approach

copy_non_const_reference

copy_const_reference

Boost.Python v1 approach

manage_new_object

Adopt a pointer and hold the instance

Use case:

T* factory() { return new T(); }

class_<T>("T");

def("Tfactory", factory, return_value_policy<manage_new_object> );