So, this is, I think, a borrowchecker terminology question.

The following get_ref method (which, to be clear, compiles just fine) turns an exclusive borrow of self into a shared borrow of self.0:

struct MyStruct(i32);
impl MyStruct {
    fn get_ref(&mut self) -> &i32 {
        &self.0
    }
}

Intuitively, I have no problems with this, it's exactly what I would expect (i.e., the borrow checker won't let you use &mut self again until &i32 reference has been dropped).

My question is: what feature permits me to "downgrade" from an &mut to an & like this? Is it "reborrowing"? "Projection"? Or maybe something involving the Deref/DerefMut traits?

2 posts - 2 participants

Read full topic