What happens when you deallocate a pointer twice or more in C++?

Question

int main() {
    Employee *e = new Employee();

    delete e;
    delete e;
    ...
    delete e;
    return 0;
}

Answer 1

Aside from the old saw about "undefined behavior" meaning anything could happen from nothing to a gateway to the seventh circle of the inferno opening up in main memory, in practice what will usually happen in most implementations is that the program will continue to run past the deletes, and then mysteriously crash sometime later in some unrelated memory allocation.