How do I use the raw_window_handle() method from winit rust crate?

I'm trying to create my first Vulkan application using Rust following adrien ben's vulkan-tutorial.

As I progressed to commit 1.2.1 I noticed he is creating the winit-window for Windows.

Because I'm developing the application on my Linux-system I decided to leave the pre-scripted path, and try to implement the windowing-part on my own.

So I stumbled across the ash-window-crate which gives me a create-surface() method that needs a window-handle as a parameter.

My problem is as follows:

I'm not able to call the raw-window-handle function from my winit-window although the docs of winit suggest the Window-Struct implements the HasRawWindowHandle-Trait, which to my understanding would expose the aforementioned function.

I'm trying to create the KHRSurface like this:

let window = WindowBuilder::new().build(&events_loop).unwrap();;
let surface_khr = unsafe { create_surface(&entry, &instance, &window.raw_window_handle(), None).unwrap(); };

and the rust-compiler complains:

error[E0277]: the trait bound `RawWindowHandle: HasRawWindowHandle` is not satisfied
  --> src/main.rs:46:70
   |
46 |         let surface_khr = unsafe { create_surface(&entry, &instance, &window.raw_window_handle(), None).unwrap(); };
   |                                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HasRawWindowHandle` is not implemented for `RawWindowHandle`
   |
   = note: required for the cast to the object type `dyn HasRawWindowHandle`

As I'm quite new to the Rust programming language I'm not very familiar with the concept of traits and therefore any help would be very appreciated.

Solution

welcome to StackOverflow.

The window does indeed implement the HasRawWindowHandle trait, and the create_surface function wants to be passed a window object that implements this trait.

That tells us that, somewhere inside of create_surface, it will call raw_window_handle on that object.

But in your code, you are already grabbing the window's raw_window_handle and passing that into the function.

So now create_surface would want to get the raw_window_handle of your raw_window_handle.

Long story short, just try passing in &window instead of &window.raw_window_handle().