Can't move because lifetime enhanced type

help
1

Can not return/move because owned by the current function. Seems the lifetime is the problem, normally this should work.

The device_physical got a life time on it, like this: PhysicalDevice<'a> inside Vulkan struct. Aside of <'a> infesting all the way up to the top struct with its need to be defined. It also makes Arc<Instance> living shorter. I don't seem to find a way to add any 'a to Arch<Instance> to solve this problem. Nor can I remove the 'a for device_physical.

pub struct Vulkan<'a>
{
    instance: Arc<Instance>,
    device_physical: PhysicalDevice<'a>,
}

     pub fn new() -> Vulkan<'a>
            {
                let required_extensions = vulkano_win::required_extensions();
                let instance = Instance::new(None, &required_extensions, None).unwrap();
                let device_physical = PhysicalDevice::enumerate(&instance).next().unwrap();
            }

     Vulkan
            {
                instance,
                device_physical,
            }
        }
2

Isn't device_physical holding the borrow of instance? If so, you're creating a self-referential struct, which is impossible in safe Rust.

3

Ah, I didn't think of that, I was convinced my Rust was wrong. According to the source, yes, it does have a field named instance: &'a Arc<Instance> in it to begin with. This tells me that I'm using Vulkano the wrong way. I actually don't need to store Arc inside Vulkan struct.

It still won't build like this, but, I also noticed that device holds physical_device. Seems I need to write it out more.

Ash wasn't like this. I figure that's a result of Vulkano trying to make unsafe code safe, or something, anyways, thanks for the hint. This opens doors now.

4

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