mirror of https://github.com/rust-lang/rust
25 lines
621 B
Rust
25 lines
621 B
Rust
use std::any::Any;
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#[derive(Debug, Clone)]
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struct S<T: 'static>(T);
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// S<&'a T> is in the return type, so we get an implied bound
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// &'a T: 'static
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fn foo<'a, T>(x: &'a T) -> (S<&'a T>, Box<dyn Any + 'static>) {
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let y = S(x);
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let z = Box::new(y.clone()) as Box<dyn Any + 'static>;
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(y, z)
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}
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fn main() {
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let x = 5;
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// Check that we require that the argument is of type `&'static String`,
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// so that the return type is well-formed.
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let (_, z) = foo(&"hello".to_string());
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//~^ ERROR temporary value dropped while borrowed
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println!("{:?}", z.downcast_ref::<S<&'static String>>());
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}
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