Arc on an array element

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#1

There are two functions:

impl PipelineLayout {
    pub fn descriptor_set_layouts(&self) -> &[Arc<DescriptorSetLayout>]
}

and

impl PersistentDescriptorSet {
    pub fn start(layout: Arc<DescriptorSetLayout>) -> PersistentDescriptorSetBuilder
}

I want to pass the first element of the array returned by the first function as the parameter to the second function, however I can't create an Arc on it because of the reference:

let layout: Arc<DescriptorSetLayout> = foo().descriptor_set_layouts().get(0)
        .expect("Couldn't find layout descriptor 0.");

// error[E0308]: mismatched types
//   --> src/main.rs:72:44
//    |
// 72 |       let layout: Arc<DescriptorSetLayout> = foo().descriptor_set_layouts().get(0)
//    |  _________________------------------------___^
//    | |                 |
//    | |                 expected due to this
// 73 | |         .expect("Couldn't find layout descriptor 0.");
//    | |_____________________________________________________^ expected struct `Arc`, found reference
//    |
//    = note: expected struct `Arc<DescriptorSetLayout>`
//            found reference `&Arc<DescriptorSetLayout>`

How can I get an Arc on an element of that array (or any other way to pass an element of that array to the second function)?

#2

You will have to clone it. For an Arc this will only increase the reference count and not clone the inner data.

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