+++ /dev/null
-// Rust-101, Part 11: Trait Objects, Box, Lifetime bounds
-// ======================================================
-
-
-// For now, we just decide that the callbacks have an argument of type `i32`.
-struct CallbacksV1<F: FnMut(i32)> {
- callbacks: Vec<F>,
-}
-
-/* struct CallbacksV2 {
- callbacks: Vec<FnMut(i32)>,
-} */
-
-pub struct Callbacks {
- callbacks: Vec<Box<FnMut(i32)>>,
-}
-
-impl Callbacks {
- // Now we can provide some functions. The constructor should be straight-forward.
- pub fn new() -> Self {
- unimplemented!()
- }
-
- // Registration simply stores the callback.
- pub fn register(&mut self, callback: Box<FnMut(i32)>) {
- self.callbacks.push(callback);
- }
-
- // We can also write a generic version of `register`, such that it will be instantiated with some concrete closure type `F`
- // and do the creation of the `Box` and the conversion from `F` to `FnMut(i32)` itself.
-
- pub fn register_generic<F: FnMut(i32)+'static>(&mut self, callback: F) {
- unimplemented!()
- }
-
- // And here we call all the stored callbacks.
- pub fn call(&mut self, val: i32) {
- // Since they are of type `FnMut`, we need to mutably iterate.
- for callback in self.callbacks.iter_mut() {
- unimplemented!()
- }
- }
-}
-
-// Now we are ready for the demo. Remember to edit `main.rs` to run it.
-pub fn main() {
- let mut c = Callbacks::new();
- c.register(Box::new(|val| println!("Callback 1: {}", val)));
- c.call(0);
-
- {
- let mut count: usize = 0;
- c.register_generic(move |val| {
- count = count+1;
- println!("Callback 2: {} ({}. time)", val, count);
- } );
- }
- c.call(1); c.call(2);
-}
-
-
-// **Exercise 11.1**: We made the arbitrary choice of using `i32` for the arguments. Generalize the data-structures above
-// to work with an arbitrary type `T` that's passed to the callbacks. Since you need to call multiple callbacks with the
-// same `t: T`, you will either have to restrict `T` to `Copy` types, or pass a borrow.
-