No problem!
On 12/22/2012 5:08 PM, simon zhang wrote:
You are right.Thank you.
2012/12/23 Jaedyn K. Draper <jaedyn.cpp...@jaedyn.co
<mailto:jaedyn.cpp...@jaedyn.co>>
If you pass it to a function like that, it passes it by value even
if it's a pointer. So it's calling the copy constructor (which you
haven't defined so it isn't printing "A start"), rather than the
regular constructor, and then destructing it.
To pass an actual pointer rather than sending it by value, you
need to do it like this:
|
B(){aa=newA;}~B(){deleteaa;}voidrun(object ct){_obj=ct();//creat a
python object
_obj.attr("fun1")(ptr(aa)); //call a function named "fun1" with
a pointer arg
_obj.attr("fun2")(ptr(aa)); //call a function named "fun2" with
a pointer arg
}
A*aa;
object _obj;|
Note that both "aa" objects are wrapped by a call to "ptr()"
Just be careful with the python when doing this, as it can cause a
crash if python tries to access that object after its C++ lifetime
has ended. So always make sure the python object's lifetime ends
before the C++ object's does.
On 12/22/2012 4:45 PM, simon zhang wrote:
when I call python's function with pointer as an argument in
boost.python, there are some troubles in destructor. The
following is a sample code
|#include <boost/python.hpp>
#include <boost/python/module.hpp>
#include <boost/python/def.hpp>
#include <string>
#include <iostream>
using namespace boost::python;
class A{
public:
A() {
std::cout<< "A start"<<std::endl;
}
~A() {std::cout<< "A end" <<std::endl;}
}
class B{
public:
B() { aa=new A
; }
~B() { delete
aa; }
void run(object ct) {
_obj=ct(); //creat a python object
_obj.attr("fun1")(aa); //call a function named "fun1" with a
pointer arg
_obj.attr("fun2")(aa); //call a function named "fun2" with a
pointer arg
}
A*aa;
object _obj;
}
BOOST_PYTHON_MODULE(ctopy)
{
class_<A> ("A",init<>())
;
class_<b> ("B",init<>())
.def("run",&B::run)
;
}|
python:
|import ctopy
class tc:
def fun1(self,tt):
print"fun1"
def fun2(self,tt):
print"fun2"
bb=ctopy.D()
bb.run(tc)|
this result:
|A start
fun1
A end
fun2
A end
A end|
note:
The "A end" has been printed three.I try it in "valgrind",there
are some errors.I just want to run the destructor once.How to do?
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