unique_ptr disposes of the object its holding when it goes out of scope unless passed to another unique_ptr or ownership is explicitly released. Presumably klipt would std::move the unique_ptr, hence the universal reference (which seems unnecessary, just pass it by value).
Am I missing something? Does it not work with std::move?
Sorry, I edited right after hitting reply to clarify that I'm assuming the intention was to std::move the unique_ptr in, since it was T&& and not T&. Would that still not work?
This is not correct; moves must leave the value in a valid state, because its destructor will still run. The correct version is actually the same as Rust's:
You're correct, sorry (I did have that at one point...). But the equivalent of Rust's pass-by-moving is to pass an r-value reference. Passing a const reference to drop is certainly an error and should be disallowed.