thank you :-)

Injecting the example pointed to by Alexander to my code, e.g.

void myUnexpected () {

std::cerr << "unexpected called\n";

throw 0;

}

...

std::set_unexpected (myUnexpected);

try {

throw runtime_error("OOOPS...");

}

catch (int) { std::cerr << "caught int\n"; }

catch (...) { std::cerr << "caught some other exception type\n"; }

still is the problem that the STDERR message of myUnexpected doesn't appear – is there anywhere code applying what you told about?

Cheers, Nick

2014-02-13 15:44 GMT+01:00 Brandon Allbery <allbery.b@gmail.com>:

On Thu, Feb 13, 2014 at 6:43 AM, Nick Rudnick <nick.rudnick@gmail.com> wrote:

3) To my surprise, every time the output stays the same:

terminate called after throwing an instance of 'std::runtime_error'

what(): OOOPS.

It's calling terminate which calls exit(), in the C++ runtime. You can't catch it at that level.

set_unexpected() may or may not help you since it's not clear that you can make it pop back to the FFI call and no further. Maybe you can use setjmp()/longjmp() or setcontext() and friends, but I'm betting its interaction with C++ is undefined (and in particular C++ finalizers/destructors don't get called).

Your best bet is to catch the exception in C++, in whatever code you are invoking from the (C context) FFI call.

Upshot: there is no global concept of exceptions that applies across all languages unless you're using something like JVM or CLR.

--

brandon s allbery kf8nh sine nomine associates

allbery.b@gmail.com ballbery@sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net