Most of them. They have to, because declaring an uninitialized variable that is later initialized by passing a reference or pointer to it to some initialization function is a rather common pattern in low-level C++.

In a sane language that would be distinguishable by having the direction explicit (i.e. things like in/out/ref in C#), and then compiler could complain for in/ref but not for out. But this is C++, so...