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// Copyright 2016 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.
// Test that .zip() specialization preserves side effects
// in sideeffectful iterator adaptors.
use std::cell::Cell;
#[derive(Debug)]
struct CountClone(Cell<i32>);
fn count_clone() -> CountClone { CountClone(Cell::new(0)) }
impl PartialEq<i32> for CountClone {
fn eq(&self, rhs: &i32) -> bool {
self.0.get() == *rhs
}
}
impl Clone for CountClone {
fn clone(&self) -> Self {
let ret = CountClone(self.0.clone());
let n = self.0.get();
self.0.set(n + 1);
ret
}
}
fn test_zip_cloned_sideffectful() {
let xs = [count_clone(), count_clone(), count_clone(), count_clone()];
let ys = [count_clone(), count_clone()];
for _ in xs.iter().cloned().zip(ys.iter().cloned()) { }
assert_eq!(&xs, &[1, 1, 1, 0][..]);
assert_eq!(&ys, &[1, 1][..]);
let xs = [count_clone(), count_clone()];
let ys = [count_clone(), count_clone(), count_clone(), count_clone()];
for _ in xs.iter().cloned().zip(ys.iter().cloned()) { }
assert_eq!(&xs, &[1, 1][..]);
assert_eq!(&ys, &[1, 1, 0, 0][..]);
}
fn test_zip_map_sideffectful() {
let mut xs = [0; 6];
let mut ys = [0; 4];
for _ in xs.iter_mut().map(|x| *x += 1).zip(ys.iter_mut().map(|y| *y += 1)) { }
assert_eq!(&xs, &[1, 1, 1, 1, 1, 0]);
assert_eq!(&ys, &[1, 1, 1, 1]);
let mut xs = [0; 4];
let mut ys = [0; 6];
for _ in xs.iter_mut().map(|x| *x += 1).zip(ys.iter_mut().map(|y| *y += 1)) { }
assert_eq!(&xs, &[1, 1, 1, 1]);
assert_eq!(&ys, &[1, 1, 1, 1, 0, 0]);
}
fn test_zip_map_rev_sideffectful() {
let mut xs = [0; 6];
let mut ys = [0; 4];
{
let mut it = xs.iter_mut().map(|x| *x += 1).zip(ys.iter_mut().map(|y| *y += 1));
it.next_back();
}
assert_eq!(&xs, &[0, 0, 0, 1, 1, 1]);
assert_eq!(&ys, &[0, 0, 0, 1]);
let mut xs = [0; 6];
let mut ys = [0; 4];
{
let mut it = xs.iter_mut().map(|x| *x += 1).zip(ys.iter_mut().map(|y| *y += 1));
(&mut it).take(5).count();
it.next_back();
}
assert_eq!(&xs, &[1, 1, 1, 1, 1, 1]);
assert_eq!(&ys, &[1, 1, 1, 1]);
}
fn test_zip_nested_sideffectful() {
let mut xs = [0; 6];
let ys = [0; 4];
{
// test that it has the side effect nested inside enumerate
let it = xs.iter_mut().map(|x| *x = 1).enumerate().zip(&ys);
it.count();
}
assert_eq!(&xs, &[1, 1, 1, 1, 1, 0]);
}
fn main() {
test_zip_cloned_sideffectful();
test_zip_map_sideffectful();
test_zip_map_rev_sideffectful();
test_zip_nested_sideffectful();
}
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