gistfile1.cpp

#include <iostream>


struct S
{
  S(int i) : i_(i) {}
  S(S const &) = delete;
  S(S &&) = delete;
  void double_() { i_ *= 2; }
  int get() const { return i_; }
  int i_;
};

S f()
{
  return { 42 };
}

S g()
{
  return { f().get() };
}

S h()
{
  S &&r = g();
  r.double_();
  return { r.get() };
}

int main()
{
  S const &r = h();
  std::cout << r.get() << std::endl;
}