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// run-pass
#![allow(unused_assignments)]
// Test that duplicate auto trait bounds in trait objects don't create new types.
#[allow(unused_assignments)]
use std::marker::Send as SendAlias;
// A dummy trait for the non-auto trait.
trait Trait {}
// A dummy struct to implement `Trait` and `Send`.
struct Struct;
impl Trait for Struct {}
// These three functions should be equivalent.
fn takes_dyn_trait_send(_: Box<dyn Trait + Send>) {}
fn takes_dyn_trait_send_send(_: Box<dyn Trait + Send + Send>) {}
fn takes_dyn_trait_send_sendalias(_: Box<dyn Trait + Send + SendAlias>) {}
impl dyn Trait + Send + Send {
fn do_nothing(&self) {}
}
fn main() {
// 1. Moving into a variable with more `Send`s and back.
let mut dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
let dyn_trait_send_send: Box<dyn Trait + Send + Send> = dyn_trait_send;
dyn_trait_send = dyn_trait_send_send;
// 2. Calling methods with different number of `Send`s.
let dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
takes_dyn_trait_send_send(dyn_trait_send);
let dyn_trait_send_send = Box::new(Struct) as Box<dyn Trait + Send + Send>;
takes_dyn_trait_send(dyn_trait_send_send);
// 3. Aliases to the trait are transparent.
let dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
takes_dyn_trait_send_sendalias(dyn_trait_send);
// 4. Calling an impl that duplicates an auto trait.
let dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
dyn_trait_send.do_nothing();
}
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