exception handeling

Xapian reports errors by throwing exceptions. For failures in things like memory allocation, you will see exceptions derived from std::exception, but exceptions related to Xapian-specific issues will be derived from Xapian::Error.

Uncaught exceptions will cause your program to terminate, so it’s wise to at least have a top-level exception handler which can catch any exceptions and report what they were. You can call the get_description() method on a Xapian::Error object to get a human readable string including all the information the object contains.

Because Xapian::Error is an abstract base class you need to catch it by reference:

try {
    do_something_with_xapian();
} catch (const Xapian::Error & e) {
    cout << "Exception: " << e.get_description() << endl;
} catch (const std::exception & e) {
    cout << "Exception: " << e.what() << endl;
}