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#![warn(clippy::map_identity)]
#![allow(clippy::needless_return)]
fn main() {
let x: [u16; 3] = [1, 2, 3];
// should lint
let _: Vec<_> = x.iter().map(not_identity).collect();
let _: Vec<_> = x.iter().collect();
let _: Option<u8> = Some(3);
let _: Result<i8, f32> = Ok(-3);
// should not lint
let _: Vec<_> = x.iter().map(|x| 2 * x).collect();
let _: Vec<_> = x.iter().map(not_identity).map(|x| return x - 4).collect();
let _: Option<u8> = None.map(|x: u8| x - 1);
let _: Result<i8, f32> = Err(2.3).map(|x: i8| {
return x + 3;
});
let _: Result<u32, u32> = Ok(1);
let _: Result<u32, u32> = Ok(1).map_err(|a: u32| a * 42);
// : u32 guides type inference
let _ = Ok(1).map_err(|a: u32| a);
let _ = Ok(1).map_err(std::convert::identity::<u32>);
}
fn issue7189() {
// should lint
let x = [(1, 2), (3, 4)].iter().copied();
let _ = x.clone();
let _ = x.clone();
let _ = x.clone();
let y = [(1, 2, (3, (4,))), (5, 6, (7, (8,)))].iter().copied();
let _ = y.clone();
// should not lint
let _ = x.clone().map(|(x, y)| (x, y, y));
let _ = x.clone().map(|(x, _y)| (x,));
let _ = x.clone().map(|(x, _)| (x,));
let _ = x.clone().map(|(x, ..)| (x,));
let _ = y.clone().map(|(x, y, (z, _))| (x, y, (z, z)));
let _ = y
.clone()
.map(|(x, y, (z, _)): (i32, i32, (i32, (i32,)))| (x, y, (z, z)));
let _ = y
.clone()
.map(|(x, y, (z, (w,))): (i32, i32, (i32, (i32,)))| (x, y, (z, (w,))));
}
fn not_identity(x: &u16) -> u16 {
*x
}
fn issue11764() {
let x = [(1, 2), (3, 4)];
// don't lint: this is an `Iterator<Item = &(i32, i32)>`
// match ergonomics makes the binding patterns into references
// so that its type changes to `Iterator<Item = (&i32, &i32)>`
let _ = x.iter().map(|(x, y)| (x, y));
let _ = x.iter().map(|x| (x.0,)).map(|(x,)| x);
// no match ergonomics for `(i32, i32)`
let _ = x.iter().copied();
}
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