44 lines
1.1 KiB
Rust
44 lines
1.1 KiB
Rust
// Copyright 2012 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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enum ast<'a> {
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num(uint),
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add(&'a ast<'a>, &'a ast<'a>)
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}
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fn build() {
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let x = num(3u);
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let y = num(4u);
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let z = add(&x, &y);
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compute(&z);
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}
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fn compute(x: &ast) -> uint {
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match *x {
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num(x) => { x }
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add(x, y) => { compute(x) + compute(y) }
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}
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}
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fn map_nums(x: &ast, f: |uint| -> uint) -> &ast {
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match *x {
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num(x) => {
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return &num(f(x)); //~ ERROR borrowed value does not live long enough
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}
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add(x, y) => {
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let m_x = map_nums(x, |z| f(z));
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let m_y = map_nums(y, |z| f(z));
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return &add(m_x, m_y); //~ ERROR borrowed value does not live long enough
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}
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}
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}
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fn main() {}
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