40 lines
1.1 KiB
Rust
40 lines
1.1 KiB
Rust
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// Copyright 2013 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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// Test that we are able to compile calls to associated fns like
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// `decode()` where the bound on the `Self` parameter references a
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// lifetime parameter of the trait. This example indicates why trait
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// lifetime parameters must be early bound in the type of the
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// associated item.
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pub enum Value<'v> {
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A(&'v str),
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B,
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}
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pub trait Decoder<'v> {
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fn read(&mut self) -> Value<'v>;
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}
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pub trait Decodable<'v, D: Decoder<'v>> {
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fn decode(d: &mut D) -> Self;
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}
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impl<'v, D: Decoder<'v>> Decodable<'v, D> for () {
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fn decode(d: &mut D) -> () {
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match d.read() {
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A(..) => (),
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B => Decodable::decode(d),
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}
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}
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}
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fn main() { }
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