#include <iostream>
#include <iomanip>
#include <cstdlib>
using namespace std;

class grandparent {
	int i;
public:
	grandparent(int initial_i): i(initial_i) {}
	int f() const {return i;}
};

class mother: public virtual grandparent {
	int j;
public:
	mother(int initial_i, int initial_j)
		: grandparent(initial_i), j(initial_j) {}

	struct table {
		ptrdiff_t diff;   //offset from end of mother to its grandparent
	};

	struct layout {
		const table *p;
		int j;
	};
};

struct father: public virtual grandparent {
	int k;
	father(int initial_i, int initial_k)
		: grandparent(initial_i), k(initial_k) {}
};

struct stepfather: public virtual grandparent {
	int k2;
	stepfather(int initial_i, int initial_k2)
		: grandparent(initial_i), k2(initial_k2) {}
};

struct grandchild: public mother, public father {
	int l;
	grandchild(int initial_i, int initial_j, int initial_k, int initial_l)
		: grandparent(initial_i),
		mother(initial_i, initial_j),
		father(initial_i, initial_k),
		l(initial_l) {}
};

struct stepgrandchild: public mother, public father, public stepfather {
	int l;
	stepgrandchild(int initial_i, int initial_j, int initial_k,
		int initial_k2, int initial_l)
		: grandparent(initial_i),
		mother(initial_i, initial_j),
		father(initial_i, initial_k),
		stepfather(initial_i, initial_k2),
		l(initial_l) {}
};

void print(const mother *m);

int main()
{
	cout << "sizeof mother, not counting its grandparent, is "
		<< sizeof (mother) - sizeof(grandparent) << ".\n\n";

	grandchild g(10, 20, 30, 40);
	cout << "mother in grandchild:\n";
	print(&g);

	stepgrandchild sg(50, 60, 70, 80, 90);
	cout << "mother in stepgrandchild:\n";
	print(&sg);

	return EXIT_SUCCESS;
}

void print(const mother *p)
{
	const mother::layout& lay =
		reinterpret_cast<const mother::layout &>(*p);
	const ptrdiff_t diff = lay.p->diff;
	const char *const cp = reinterpret_cast<const char *>(p)
		+ sizeof (mother) - sizeof (grandparent);
	const grandparent *const gp =
		reinterpret_cast<const grandparent *>(cp + diff);

	cout
		<< p << " == address of mother\n"
		<< static_cast<const void *>(cp)
			<< " == address of first byte after mother"
			" (not counting its grandparent)\n"
		<< hex << setw(10) << diff << dec
			<< " == offset to mother's grandparent (in hex)\n"
		<< gp << " == address of mother's grandparent\n"
		<< static_cast<const grandparent *>(p)
			<< " == static_cast<const grandparent *>(p)\n"
		<< "grandparent's f returns " << gp->f() << ".\n\n";
}