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#![warn(clippy::needless_for_each)]
#![allow(unused)]
#![allow(
clippy::let_unit_value,
clippy::match_single_binding,
clippy::needless_return,
clippy::uninlined_format_args
)]
use std::collections::HashMap;
fn should_lint() {
let v: Vec<i32> = Vec::new();
let mut acc = 0;
for elem in v.iter() {
//~^ needless_for_each
acc += elem;
}
for elem in v.into_iter() {
//~^ needless_for_each
acc += elem;
}
for elem in [1, 2, 3].iter() {
//~^ needless_for_each
acc += elem;
}
let mut hash_map: HashMap<i32, i32> = HashMap::new();
for (k, v) in hash_map.iter() {
//~^ needless_for_each
acc += k + v;
}
for (k, v) in hash_map.iter_mut() {
//~^ needless_for_each
acc += *k + *v;
}
for k in hash_map.keys() {
//~^ needless_for_each
acc += k;
}
for v in hash_map.values() {
//~^ needless_for_each
acc += v;
}
fn my_vec() -> Vec<i32> {
Vec::new()
}
for elem in my_vec().iter() {
//~^ needless_for_each
acc += elem;
}
}
fn should_not_lint() {
let v: Vec<i32> = Vec::new();
let mut acc = 0;
// `for_each` argument is not closure.
fn print(x: &i32) {
println!("{}", x);
}
v.iter().for_each(print);
// User defined type.
struct MyStruct {
v: Vec<i32>,
}
impl MyStruct {
fn iter(&self) -> impl Iterator<Item = &i32> {
self.v.iter()
}
}
let s = MyStruct { v: Vec::new() };
s.iter().for_each(|elem| {
acc += elem;
});
// `for_each` follows long iterator chain.
v.iter().chain(v.iter()).for_each(|v| {
acc += v;
});
v.as_slice().iter().for_each(|v| {
acc += v;
});
s.v.iter().for_each(|v| {
acc += v;
});
// `return` is used in `Loop` of the closure.
v.iter().for_each(|v| {
for i in 0..*v {
if i == 10 {
return;
} else {
println!("{}", v);
}
}
if *v == 20 {
return;
} else {
println!("{}", v);
}
});
// Previously transformed iterator variable.
let it = v.iter();
it.chain(v.iter()).for_each(|elem| {
acc += elem;
});
// `for_each` is not directly in a statement.
match 1 {
_ => v.iter().for_each(|elem| {
acc += elem;
}),
}
// `for_each` is in a let binding.
let _ = v.iter().for_each(|elem| {
acc += elem;
});
// `for_each` has a closure with an unsafe block.
v.iter().for_each(|elem| unsafe {
acc += elem;
});
}
fn main() {}
mod issue14734 {
fn let_desugar(rows: &[u8]) {
let mut v = vec![];
for x in rows.iter() { _ = v.push(x) }
//~^ needless_for_each
}
fn do_something(_: &u8, _: u8) {}
fn single_expr(rows: &[u8]) {
for x in rows.iter() { do_something(x, 1u8); }
//~^ needless_for_each
}
}
fn issue15256() {
let vec: Vec<i32> = Vec::new();
for v in vec.iter() { println!("{v}"); }
//~^ needless_for_each
}
|
