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#![warn(clippy::manual_flatten)]
#![allow(clippy::useless_vec, clippy::uninlined_format_args)]
fn main() {
// Test for loop over implicitly adjusted `Iterator` with `if let` expression
let x = vec![Some(1), Some(2), Some(3)];
for y in x.into_iter().flatten() {
println!("{}", y);
}
// Test for loop over implicitly adjusted `Iterator` with `if let` statement
let y: Vec<Result<i32, i32>> = vec![];
for n in y.clone().into_iter().flatten() {
println!("{}", n);
}
// Test for loop over by reference
for n in y.iter().flatten() {
println!("{}", n);
}
// Test for loop over an implicit reference
let z = &y;
for n in z.iter().flatten() {
println!("{}", n);
}
// Test for loop over `Iterator` with `if let` expression
let z = vec![Some(1), Some(2), Some(3)];
let z = z.iter();
for m in z.flatten() {
println!("{}", m);
}
// Using the `None` variant should not trigger the lint
// Note: for an autofixable suggestion, the binding in the for loop has to take the
// name of the binding in the `if let`
let z = vec![Some(1), Some(2), Some(3)];
for n in z {
if n.is_none() {
println!("Nada.");
}
}
// Using the `Err` variant should not trigger the lint
for n in y.clone() {
if let Err(e) = n {
println!("Oops: {}!", e);
}
}
// Having an else clause should not trigger the lint
for n in y.clone() {
if let Ok(n) = n {
println!("{}", n);
} else {
println!("Oops!");
}
}
let vec_of_ref = vec![&Some(1)];
for n in vec_of_ref.iter().copied().flatten() {
println!("{:?}", n);
}
let vec_of_ref = &vec_of_ref;
for n in vec_of_ref.iter().copied().flatten() {
println!("{:?}", n);
}
let slice_of_ref = &[&Some(1)];
for n in slice_of_ref.iter().copied().flatten() {
println!("{:?}", n);
}
struct Test {
a: usize,
}
let mut vec_of_struct = [Some(Test { a: 1 }), None];
// Usage of `if let` expression should not trigger lint
for n in vec_of_struct.iter_mut() {
if let Some(z) = n {
*n = None;
}
}
// Using manual flatten should not trigger the lint
for n in vec![Some(1), Some(2), Some(3)].iter().flatten() {
println!("{}", n);
}
// Using nested `Some` pattern should not trigger the lint
for n in vec![Some((1, Some(2)))] {
if let Some((_, Some(n))) = n {
println!("{}", n);
}
}
macro_rules! inner {
($id:ident / $new:pat => $action:expr) => {
if let Some($new) = $id {
$action;
}
};
}
// Usage of `if let` expression with macro should not trigger lint
for ab in [Some((1, 2)), Some((3, 4))] {
inner!(ab / (c, d) => println!("{c}-{d}"));
}
macro_rules! args {
($($arg:expr),*) => {
vec![$(Some($arg)),*]
};
}
// Usage of `if let` expression with macro should not trigger lint
for n in args!(1, 2, 3) {
if let Some(n) = n {
println!("{:?}", n);
}
}
// This should trigger the lint, but the applicability is `MaybeIncorrect`
let z = vec![Some(1), Some(2), Some(3)];
for n in z.into_iter().flatten() {
println!("{:?}", n);
}
run_unformatted_tests();
}
#[rustfmt::skip]
fn run_unformatted_tests() {
// Skip rustfmt here on purpose so the suggestion does not fit in one line
for n in vec![
//~^ manual_flatten
Some(1),
Some(2),
Some(3)
].iter().flatten() {
println!("{:?}", n);
}
}
|
