Return From Value, Reference, And Pointer

//Need to explain more with Compiler Optimization with RETURN BY VALUE~
//p.732, p358, C++ Primer

class LargeObject {
};

LargeObject return_by_value()
{
 LargeObject lb;
 return lb; // make a copy of large object, then return it,  might be slow
}

LargeObject& return_same_reference_from_parameter(LargeObject& lb)
{
 //do something with lb,
  return lb; //ok

}

LargeObject& return_by_local_reference_is_bad()
{
 LargeObject lb;
 return lb; //oops, run time error, lb is destroyed after return
            //compiler will warn!

}

LargeObject& return_from_heap_but_someone_has_to_free_it()
{
 LargeObject *lb = new LargeObject();

 return *lb; // ok, BUT who is responsible to free the memory?
}

LargeObject* return_from_heap_but_someone_has_to_free_too()
{

 LargeObject *lb = new LargeObject();
 return lb;
}