// move_semantics2.rs // Make me compile without changing line 9! Scroll down for hints :) pub fn main() { let vec0 = Vec::new(); let mut vec1 = fill_vec(vec0); // Do not change the following line! println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0); vec1.push(88); println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1); } fn fill_vec(vec: Vec) -> Vec { let mut vec = vec; vec.push(22); vec.push(44); vec.push(66); vec } // So `vec0` is being *moved* into the function `fill_vec` when we call it on // line 6, which means it gets dropped at the end of `fill_vec`, which means we // can't use `vec0` again on line 9 (or anywhere else in `main` after the // `fill_vec` call for that matter). We could fix this in a few ways, try them // all! // 1. Make another, separate version of the data that's in `vec0` and pass that // to `fill_vec` instead. // 2. Make `fill_vec` borrow its argument instead of taking ownership of it, // and then copy the data within the function in order to return an owned // `Vec` // 3. Make `fill_vec` *mutably* borrow its argument (which will need to be // mutable), modify it directly, then not return anything. Then you can get rid // of `vec1` entirely -- note that this will change what gets printed by the // first `println!`