C++ vs Java constructors

Question

According to John C. Mitchell - Concepts in programming languages,

[...] Java guarantees that a constructor is called whenever an object is created.

Answer 1

Giving an interpretation, I have a suggestion about why the author says that for Java, without looking for any corner cases which I think don't address really the problem: you could think for example that PODs are not objects.

The fact that C++ has unsafe type casts is much more well known. For example, using a simple mixture of C and C++, you could do this:

class A {
   int x;
public:
   A() : X(0) {}
   virtual void f() { x=x+1; }
   virtual int getX() { return x; }
};

int main() {
   A *a = (A *)malloc(sizeof(A));
   cout << a->getX();
   free(a);
}

This is a perfectly acceptable program in C++ and uses the unchecked form of type cast to avoid constructor invocation. In this case x is not initialized, so we might expect an unpredictable behaviour.

However, there might be other cases in which also Java fails to apply this rule, the mention of serialized object is perfectly reasonable and correct, even though you know for sure that the object has already been constructed in some way (unless you do some hacking on the serialized encoding of course).