C++ const& binding to temporary object

Question

Consider the following code:

 class Abc
 {
 public:
     Abc() { std::cout << " ABC::ABC\n"; }
     Abc& doIT() { std::cout << " Abc::doIT\n"; return *this; }
     ~Abc() { std::cout << " ABC::~ABC\n"; }
 };

Usage:

const Abc& ap = Abc().doIT(); //After this line ap references garbage

My question is why temp Abc destroyed and not binded to ap ?

Answer 1

Lifetime extension only happens when you bind a reference to a prvalue directly .
In your case, the type of the expression Abc().doIT() is Abc& (an lvalue reference), not Abc .
This is not a prvalue, so lifetime extension does not apply.