Rust has ManuallyDrop, which is exactly the functionality you’re describing. It works just fine for those types of programs. The speed of the two is going to be

Rust has ManuallyDrop, which is exactly the functionality you’re describing. It works just fine for those types of programs. The speed of the two is going to be largely dependent on the amount of effort that has gone into optimizing either one, not on some theoretical performance bound. They’re both basically the same there. There are tons of examples of this in the wild at this point.