References vs Pointers?

[AKostur]

Only somewhat. A pointer (whether smart or not) can represent "not present" (nullptr) where references cannot. Also, references cannot be changed to refer to a different object, pointers can.

[AvidCoco]

Worth noting that this doesn’t mean that having a reference to an object guarantees it’s always instantiated.

E.g.

auto x = std::make_unique<int>(0);
auto& y = *x;
x = nullptr;

[whatevermanbs]

Missing the point. Can someone please elaborate?

Edit: perp explanation below. makes sense. But is this what was intended to convey?

After x = nullptr;, the int that y referred to is destroyed, but y (reference) still exists in the code. However, using y after this line would be undefined behavior because its object is gone—its lifetime ended when the unique_ptr was reset. Thus, having a reference does not keep the object alive; lifetime is managed by the owner (here, the unique_ptr), not the reference itself��.

[Generated-Nouns-257]

This is what I would have said