41 lines
1018 B
Rust
41 lines
1018 B
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
// no-pretty-expanded FIXME #15189
|
|
|
|
// pretty-expanded FIXME #23616
|
|
|
|
#![feature(core)]
|
|
|
|
use std::iter::Unfold;
|
|
|
|
// Unfold had a bug with 'a that mean it didn't work
|
|
// cross-crate
|
|
|
|
pub fn main() {
|
|
fn count(st: &mut usize) -> Option<usize> {
|
|
if *st < 10 {
|
|
let ret = Some(*st);
|
|
*st += 1;
|
|
ret
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
let mut it = Unfold::new(0, count);
|
|
let mut i = 0;
|
|
for counted in it {
|
|
assert_eq!(counted, i);
|
|
i += 1;
|
|
}
|
|
assert_eq!(i, 10);
|
|
}
|