30 lines
460 B
Rust
30 lines
460 B
Rust
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//@ run-pass
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//
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// issue: <https://github.com/rust-lang/rust/issues/131813>
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#![feature(trait_upcasting)]
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trait Pollable {
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#[allow(unused)]
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fn poll(&self) {}
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}
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trait FileIo: Pollable + Send + Sync {
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fn read(&self) {}
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}
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trait Terminal: Send + Sync + FileIo {}
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struct A;
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impl Pollable for A {}
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impl FileIo for A {}
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impl Terminal for A {}
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fn main() {
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let a = A;
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let b = &a as &dyn Terminal;
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let c = b as &dyn FileIo;
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c.read();
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}
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