Re: [Boost-users] dynamic_pointer_cast doesn't work as expected

From: Marshall Clow (marshall_at_[hidden])
Date: 2007-09-28 17:10:42

At 11:37 PM +0300 9/28/07, Peter Dimov wrote:
>Diego Bernini:
>
>  > Hi,
>>  see these lines:
>>
>>  boost::shared_ptr<Executor> executor(&(createExecutor(subclass,name)));
>>  if(!executor) {
>>               throw LoadingClassException("createExecutor function
>>  of\""+subclass+"\" return null.");
>>  }
>>  //executor points to an object of class ExecDebugger that IS A Executor
>>  //(it's a plugin loaded at run time via Qt)
>>
>>  boost::shared_ptr<Nameable> a=executor;
>>  boost::shared_ptr<Executor> sp;
>>
>>  sp=boost::dynamic_pointer_cast<Executor>(a);
>
>It's possible that dynamic_cast doesn't work across dynamic libraries on
>your platform.

See 
<http://lists.apple.com/archives/xcode-users/2006/Jul/msg00301.html> 
(start there)
and 
<http://lists.apple.com/archives/xcode-users/2006/Jul/msg00386.html> 
and <http://developer.apple.com/technotes/tn2007/tn2185.html> for a 
description of this problem (on Mac OS X, but really a gcc problem) - 
especially the part around "Comparing types is important for catching 
exceptions, dynamic_cast, and comparing type_info's obtained by a 
typeid expression."
-- 
-- Marshall
Marshall Clow     Idio Software   <mailto:marshall_at_[hidden]>
It is by caffeine alone I set my mind in motion.
It is by the beans of Java that thoughts acquire speed,
the hands acquire shaking, the shaking becomes a warning.
It is by caffeine alone I set my mind in motion.