35 lines
928 B
Rust
35 lines
928 B
Rust
// 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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use std::iter::Unfold;
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// Unfold had a bug with 'a that mean it didn't work
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// cross-crate
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pub fn main() {
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fn count(st: &mut uint) -> Option<uint> {
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if *st < 10 {
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let ret = Some(*st);
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*st += 1;
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ret
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} else {
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None
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}
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}
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let mut it = Unfold::new(0, count);
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let mut i = 0;
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for counted in it {
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assert_eq!(counted, i);
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i += 1;
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}
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assert_eq!(i, 10);
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}
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