37 lines
894 B
Rust
37 lines
894 B
Rust
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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::convert::Into;
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trait Trait {
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fn to_u8(&self) -> u8;
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}
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trait WithAssoc {
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type Item;
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fn to_item(&self) -> Self::Item;
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}
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impl<T, U> Trait for T where T: WithAssoc<Item=U>, U: Into<u8> {
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fn to_u8(&self) -> u8 {
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self.to_item().into()
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}
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}
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impl WithAssoc for u8 {
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type Item = u8;
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fn to_item(&self) -> u8 { *self }
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}
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impl Trait for u8 {}
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fn main() {
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assert!(3u8.to_u8() == 3u8);
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}
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