vulkano | Safe and rich Rust wrapper around the Vulkan API

Make a constant with static lifetime:

So the reason for the error message is that instance is a local variable in your instantiate function. Because you aren't moving its ownership to the return value, it will be dropped at the end of the function.

But then if it gets dropped, any reference to it would be invalid. That's why Rust doesn't let you return something holding a reference to the local variable.

First, your struct is redundant, because PhysicalDevice already holds a reference for the instance. Even without the local variable problem, I think you'd run into an ownership problem.

Second, let's say you rewrite and get rid of your InstanceInfo struct and instead you want to just return a PhysicalDevice<'static>. Well if that's what you promise to the compiler, then you have to make sure that the instance you create will live for as long as the program lives.

You can do that either by having instance be a static variable of your module, or by creating it at the very beginning of the program and then simply pass a reference ot it around.

For example

From vulkano-rs/vulkano#1527:

AutoCommandBufferBuilder::new renamed to AutoCommandBufferBuilder::primary/secondary. For primary form there is a new additional 3rd parameter. Use CommandBufferUsage::MultipleSubmit for this parameter to fulfill the same behavior you previously had with old new constructor.

You are looking for the Vulkan-Loader/LoaderAndLayerInterface.md documentation.

The app interfaces with The Loader (sometimes called Vulkan RT, or Vulkan Runtime). That is the vulkan-1.dll (or so).

The Loader also has vulkan-1.lib, which is classic dll shim. It is where the loading of core version and WSI commands happens, but you can skip the lib and do it all manually directly from the dll using vkGetInstanceProcAddr.

Then you have ICDs (Installable Client Drivers). Those are something like nvoglv64.dll, and you can have more of them on your PC (e.g. Intel iGPU + NV). The name is arbitrary and vendor specific. The Loader finds them via config files.

Now when you call something to a command obtained with vkGetInstanceProcAddress (which is everything if you use the *.lib only), you get onto a loader trampoline, which calls a chain of layers, after which the relevant ICD (or all of them) are called. Then the callstack is unwound, so it goes the other direction until the returned to the app. The loader mutexes and merges the the input and output to the ICD.

Commands obtained with vkGetDeviceProcAddress are little bit more streamlined, as they do not require to be mutexed or merged and are meant to be passed to the ICD without much intervention from the Loader.

The code is also at the same repo: trampoline.c, and loader.c. It's pretty straightforward; every layer just calls the layer below it. Starts at the trampoline, and ends with the terminator layer which in turn will call the ICD layer.

[Is it] a reference to the unit type?

That's exactly what it is. Its just passing a reference & to the value ().

Similar syntax:

• &1: a reference to a literal 1.
• &[]: a reference to an empty slice.

I have checked the library and the version of vulkano_win and it seems to properly extend WindowBuilder I will post the dependencies in my Cargo.toml below.

In short, you are correct. The issue is that the VkSurfaceBuild trait, is implemented for winit 0.22's WindowBuilder and not winit 0.23's WindowBuilder.

So to fix your issue, you need to update your Cargo.toml to use winit 0.22 instead of 0.23.

Example:

So I found myself very naive towards Rust's complex trait system. The only change I had to do was to add a 'static lifetime on to the associate type Vertex which fixes the problem which is really confusing the fact that the error shows as a circular reference.