#include <vector>

#ifndef UN1_A_H
#define UN1_A_H

#include "B.h"

class A {
public:
    std::vector<B&> get();
};


#endif //UN1_A_H

#include "A.h"
#include "B.h"

std::vector<B &> A::get() {
    std::vector<B&> bs;

    bs.push_back(*(new B()));
    bs.push_back(*(new B()));

    return bs;
}

#include "A.h"
#include "B.h"

int main() {
    A& a = *(new A());
    B& b = a.get()[0];
}