rust/clippy_tests/examples/for_loop.rs

365 lines
8.0 KiB
Rust

#![feature(plugin, step_by, inclusive_range_syntax)]
#![plugin(clippy)]
use std::collections::*;
use std::rc::Rc;
static STATIC: [usize; 4] = [ 0, 1, 8, 16 ];
const CONST: [usize; 4] = [ 0, 1, 8, 16 ];
#[warn(clippy)]
fn for_loop_over_option_and_result() {
let option = Some(1);
let result = option.ok_or("x not found");
let v = vec![0,1,2];
// check FOR_LOOP_OVER_OPTION lint
for x in option {
println!("{}", x);
}
// check FOR_LOOP_OVER_RESULT lint
for x in result {
println!("{}", x);
}
for x in option.ok_or("x not found") {
println!("{}", x);
}
// make sure LOOP_OVER_NEXT lint takes precedence when next() is the last call in the chain
for x in v.iter().next() {
println!("{}", x);
}
// make sure we lint when next() is not the last call in the chain
for x in v.iter().next().and(Some(0)) {
println!("{}", x);
}
for x in v.iter().next().ok_or("x not found") {
println!("{}", x);
}
// check for false positives
// for loop false positive
for x in v {
println!("{}", x);
}
// while let false positive for Option
while let Some(x) = option {
println!("{}", x);
break;
}
// while let false positive for Result
while let Ok(x) = result {
println!("{}", x);
break;
}
}
struct Unrelated(Vec<u8>);
impl Unrelated {
fn next(&self) -> std::slice::Iter<u8> {
self.0.iter()
}
fn iter(&self) -> std::slice::Iter<u8> {
self.0.iter()
}
}
#[warn(needless_range_loop, explicit_iter_loop, explicit_into_iter_loop, iter_next_loop, reverse_range_loop, explicit_counter_loop, for_kv_map)]
#[warn(unused_collect)]
#[allow(linkedlist, shadow_unrelated, unnecessary_mut_passed, cyclomatic_complexity, similar_names)]
#[allow(many_single_char_names)]
fn main() {
const MAX_LEN: usize = 42;
let mut vec = vec![1, 2, 3, 4];
let vec2 = vec![1, 2, 3, 4];
for i in 0..vec.len() {
println!("{}", vec[i]);
}
for i in 0..vec.len() {
let i = 42; // make a different `i`
println!("{}", vec[i]); // ok, not the `i` of the for-loop
}
for i in 0..vec.len() { let _ = vec[i]; }
// ICE #746
for j in 0..4 {
println!("{:?}", STATIC[j]);
}
for j in 0..4 {
println!("{:?}", CONST[j]);
}
for i in 0..vec.len() {
println!("{} {}", vec[i], i);
}
for i in 0..vec.len() { // not an error, indexing more than one variable
println!("{} {}", vec[i], vec2[i]);
}
for i in 0..vec.len() {
println!("{}", vec2[i]);
}
for i in 5..vec.len() {
println!("{}", vec[i]);
}
for i in 0..MAX_LEN {
println!("{}", vec[i]);
}
for i in 0...MAX_LEN {
println!("{}", vec[i]);
}
for i in 5..10 {
println!("{}", vec[i]);
}
for i in 5...10 {
println!("{}", vec[i]);
}
for i in 5..vec.len() {
println!("{} {}", vec[i], i);
}
for i in 5..10 {
println!("{} {}", vec[i], i);
}
for i in 10..0 {
println!("{}", i);
}
for i in 10...0 {
println!("{}", i);
}
for i in MAX_LEN..0 {
println!("{}", i);
}
for i in 5..5 {
println!("{}", i);
}
for i in 5...5 { // not an error, this is the range with only one element “5”
println!("{}", i);
}
for i in 0..10 { // not an error, the start index is less than the end index
println!("{}", i);
}
for i in -10..0 { // not an error
println!("{}", i);
}
for i in (10..0).map(|x| x * 2) { // not an error, it can't be known what arbitrary methods do to a range
println!("{}", i);
}
// testing that the empty range lint folds constants
for i in 10..5+4 {
println!("{}", i);
}
for i in (5+2)..(3-1) {
println!("{}", i);
}
for i in (5+2)..(8-1) {
println!("{}", i);
}
for i in (2*2)..(2*3) { // no error, 4..6 is fine
println!("{}", i);
}
for i in (10..8).step_by(-1) {
println!("{}", i);
}
let x = 42;
for i in x..10 { // no error, not constant-foldable
println!("{}", i);
}
// See #601
for i in 0..10 { // no error, id_col does not exist outside the loop
let mut id_col = vec![0f64; 10];
id_col[i] = 1f64;
}
for _v in vec.iter() { }
for _v in vec.iter_mut() { }
let out_vec = vec![1,2,3];
for _v in out_vec.into_iter() { }
let array = [1, 2, 3];
for _v in array.into_iter() {}
for _v in &vec { } // these are fine
for _v in &mut vec { } // these are fine
for _v in [1, 2, 3].iter() { }
for _v in (&mut [1, 2, 3]).iter() { } // no error
for _v in [0; 32].iter() {}
for _v in [0; 33].iter() {} // no error
let ll: LinkedList<()> = LinkedList::new();
for _v in ll.iter() { }
let vd: VecDeque<()> = VecDeque::new();
for _v in vd.iter() { }
let bh: BinaryHeap<()> = BinaryHeap::new();
for _v in bh.iter() { }
let hm: HashMap<(), ()> = HashMap::new();
for _v in hm.iter() { }
let bt: BTreeMap<(), ()> = BTreeMap::new();
for _v in bt.iter() { }
let hs: HashSet<()> = HashSet::new();
for _v in hs.iter() { }
let bs: BTreeSet<()> = BTreeSet::new();
for _v in bs.iter() { }
for _v in vec.iter().next() { }
let u = Unrelated(vec![]);
for _v in u.next() { } // no error
for _v in u.iter() { } // no error
let mut out = vec![];
vec.iter().map(|x| out.push(x)).collect::<Vec<_>>();
let _y = vec.iter().map(|x| out.push(x)).collect::<Vec<_>>(); // this is fine
// Loop with explicit counter variable
let mut _index = 0;
for _v in &vec { _index += 1 }
let mut _index = 1;
_index = 0;
for _v in &vec { _index += 1 }
// Potential false positives
let mut _index = 0;
_index = 1;
for _v in &vec { _index += 1 }
let mut _index = 0;
_index += 1;
for _v in &vec { _index += 1 }
let mut _index = 0;
if true { _index = 1 }
for _v in &vec { _index += 1 }
let mut _index = 0;
let mut _index = 1;
for _v in &vec { _index += 1 }
let mut _index = 0;
for _v in &vec { _index += 1; _index += 1 }
let mut _index = 0;
for _v in &vec { _index *= 2; _index += 1 }
let mut _index = 0;
for _v in &vec { _index = 1; _index += 1 }
let mut _index = 0;
for _v in &vec { let mut _index = 0; _index += 1 }
let mut _index = 0;
for _v in &vec { _index += 1; _index = 0; }
let mut _index = 0;
for _v in &vec { for _x in 0..1 { _index += 1; }; _index += 1 }
let mut _index = 0;
for x in &vec { if *x == 1 { _index += 1 } }
let mut _index = 0;
if true { _index = 1 };
for _v in &vec { _index += 1 }
let mut _index = 1;
if false { _index = 0 };
for _v in &vec { _index += 1 }
let mut index = 0;
{ let mut _x = &mut index; }
for _v in &vec { _index += 1 }
let mut index = 0;
for _v in &vec { index += 1 }
println!("index: {}", index);
for_loop_over_option_and_result();
let m : HashMap<u64, u64> = HashMap::new();
for (_, v) in &m {
let _v = v;
}
let m : Rc<HashMap<u64, u64>> = Rc::new(HashMap::new());
for (_, v) in &*m {
let _v = v;
// Here the `*` is not actually necesarry, but the test tests that we don't suggest
// `in *m.values()` as we used to
}
let mut m : HashMap<u64, u64> = HashMap::new();
for (_, v) in &mut m {
let _v = v;
}
let m: &mut HashMap<u64, u64> = &mut HashMap::new();
for (_, v) in &mut *m {
let _v = v;
}
let m : HashMap<u64, u64> = HashMap::new();
let rm = &m;
for (k, _value) in rm {
let _k = k;
}
test_for_kv_map();
}
#[allow(used_underscore_binding)]
fn test_for_kv_map() {
let m : HashMap<u64, u64> = HashMap::new();
// No error, _value is actually used
for (k, _value) in &m {
let _ = _value;
let _k = k;
}
}