operator new with empty exception-specification calling constructor when allocation returns 0
void * operator new (size_t s, PersistentMemory * m) throw()
   {return m->allocatePersistentMemory(s);}

void *myalloc (size_t) { return 0; }
void * operator new (size_t s) throw() { return myalloc(s); }
struct Foo {
    std::string s;
    Foo () { std::cout << this << std::endl; }
};
int main () {
    Foo *f = new Foo;
    if (f == 0) std::cout << "f is NULL" << std::endl;
}

void *myalloc (size_t) { return 0; }
void * operator new (size_t s) throw() { return myalloc(s); }
struct Foo {
    std::string s;
    Foo () { std::cout << this << std::endl; }
    void * operator new (size_t s) { return myalloc(s); }
};
int main () {
    Foo *f = new Foo;
    if (f == 0) std::cout << "f is NULL" << std::endl;
}