boost dynamic_pointer_cast, shared_ptr not working as expected

Member

Posts: 45
Joined: 2006.11

Post: #1

Apr 25, 2007 — 03:49 PM

I am trying to use inheritance and shared_ptr from the boost library. But I'm unable to properly downcast shared_ptr of base classes into shared_ptr of subclasses.

Here is the simplest example I could write:

Code:

#include <iostream>

#include <boost/shared_ptr.hpp>

#include <cassert>

using namespace std;

class base {

public:

  virtual ~base() {}

};

class sub : public base

{

  public:

  virtual ~sub() {}

};

#define BASE_CAST(x) boost::dynamic_pointer_cast<sub, base>(x)

int main()

{

  boost::shared_ptr<base> b(new base());

  assert(b.get());

  boost::shared_ptr<sub> s(BASE_CAST(b));

  assert(s.get());

  return 0;

}

And here is the output when run:

Code:

jeremybell@jeremybell-desktop:~$ ./a.out

a.out: test.cpp:25: int main(): Assertion `s.get()' failed.

Aborted (core dumped)

Am I doing something wrong?

Regards,
JeroMiya

JeroMiya

Member

Posts: 45
Joined: 2006.11

Post: #2

Apr 25, 2007 — 04:00 PM

nevermind, I see what the problem is:

it should be:

shared_ptr<base> b(new sub());

masumbuet

Apprentice

Posts: 6
Joined: 2008.11

Post: #3

Nov 24, 2008 — 01:29 AM

This post means you could use "boost" for iPhone. But I could not do that so far

. Would you please describe the way/ procedure to use boost library for iPhone application development? Thanks in advance.

Possibly Related Threads...

Thread:		Author	Replies:	Views:	Last Post
	SDL shared_ptr problems	Bearcosta	6	6,048	Mar 31, 2011 04:25 AM Last Post: TomorrowPlusX