#include <iostream>
using namespace std;
 
namespace mylib {
	struct Person {
		static int counter; 
		int id; 
		Person() : id(++counter) {}
		void whoami() { cout << "I'm "<<id<<endl; }
	};  //A
	struct Friend: Person {}; //B -> A
	int Person::counter=0; 
}
struct Employee : virtual mylib::Person {}; // C->A
struct Colleague : Employee, mylib::Friend {};  // D->(B,c)
 
int main() {
	mylib::Friend p1;   // ok !  
	p1.whoami(); 
 
	Employee p2; 
	p2.whoami(); 
 
	Colleague p3;   // No diamond ! 
	//p3.whoami();  // ouch !! not allowed: no diamond so the function has to be called for which base object ? 
	p3.Employee::whoami();   // first occurence of A
	p3.mylib::Friend::whoami(); // second second occurence of A
 
	return 0;
}

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