diff --git a/clippy_lints/src/methods/iter_overeager_cloned.rs b/clippy_lints/src/methods/iter_overeager_cloned.rs index b93f1399eae..54c9ca435a4 100644 --- a/clippy_lints/src/methods/iter_overeager_cloned.rs +++ b/clippy_lints/src/methods/iter_overeager_cloned.rs @@ -1,11 +1,12 @@ use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::source::snippet; -use clippy_utils::ty::{get_iterator_item_ty, is_copy}; +use clippy_utils::ty::{get_iterator_item_ty, implements_trait, is_copy}; use itertools::Itertools; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_lint::LateContext; use rustc_middle::ty; +use rustc_span::sym; use std::ops::Not; use super::ITER_OVEREAGER_CLONED; @@ -20,9 +21,16 @@ pub(super) fn check<'tcx>( map_arg: &[hir::Expr<'_>], ) { // Check if it's iterator and get type associated with `Item`. - let inner_ty = match get_iterator_item_ty(cx, cx.typeck_results().expr_ty_adjusted(recv)) { - Some(ty) => ty, - _ => return, + let inner_ty = if_chain! { + if let Some(iterator_trait_id) = cx.tcx.get_diagnostic_item(sym::Iterator); + let recv_ty = cx.typeck_results().expr_ty(recv); + if implements_trait(cx, recv_ty, iterator_trait_id, &[]); + if let Some(inner_ty) = get_iterator_item_ty(cx, cx.typeck_results().expr_ty_adjusted(recv)); + then { + inner_ty + } else { + return; + } }; match inner_ty.kind() { diff --git a/tests/ui/iter_overeager_cloned.fixed b/tests/ui/iter_overeager_cloned.fixed index a9041671101..56761ebbcb8 100644 --- a/tests/ui/iter_overeager_cloned.fixed +++ b/tests/ui/iter_overeager_cloned.fixed @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::iter_overeager_cloned, clippy::redundant_clone, clippy::filter_next)] +#![allow(dead_code)] fn main() { let vec = vec!["1".to_string(), "2".to_string(), "3".to_string()]; @@ -43,3 +44,8 @@ fn main() { // Should probably stay as it is. let _ = [0, 1, 2, 3, 4].iter().cloned().take(10); } + +// #8527 +fn cloned_flatten(x: Option<&Option>) -> Option { + x.cloned().flatten() +} diff --git a/tests/ui/iter_overeager_cloned.rs b/tests/ui/iter_overeager_cloned.rs index dd04e33a4b3..98321d889b5 100644 --- a/tests/ui/iter_overeager_cloned.rs +++ b/tests/ui/iter_overeager_cloned.rs @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::iter_overeager_cloned, clippy::redundant_clone, clippy::filter_next)] +#![allow(dead_code)] fn main() { let vec = vec!["1".to_string(), "2".to_string(), "3".to_string()]; @@ -45,3 +46,8 @@ fn main() { // Should probably stay as it is. let _ = [0, 1, 2, 3, 4].iter().cloned().take(10); } + +// #8527 +fn cloned_flatten(x: Option<&Option>) -> Option { + x.cloned().flatten() +} diff --git a/tests/ui/iter_overeager_cloned.stderr b/tests/ui/iter_overeager_cloned.stderr index e36b0e36fbd..0582700fd16 100644 --- a/tests/ui/iter_overeager_cloned.stderr +++ b/tests/ui/iter_overeager_cloned.stderr @@ -1,5 +1,5 @@ error: called `cloned().last()` on an `Iterator`. It may be more efficient to call `last().cloned()` instead - --> $DIR/iter_overeager_cloned.rs:7:29 + --> $DIR/iter_overeager_cloned.rs:8:29 | LL | let _: Option = vec.iter().cloned().last(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().last().cloned()` @@ -7,13 +7,13 @@ LL | let _: Option = vec.iter().cloned().last(); = note: `-D clippy::iter-overeager-cloned` implied by `-D warnings` error: called `cloned().next()` on an `Iterator`. It may be more efficient to call `next().cloned()` instead - --> $DIR/iter_overeager_cloned.rs:9:29 + --> $DIR/iter_overeager_cloned.rs:10:29 | LL | let _: Option = vec.iter().chain(vec.iter()).cloned().next(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().chain(vec.iter()).next().cloned()` error: called `cloned().count()` on an `Iterator`. It may be more efficient to call `count()` instead - --> $DIR/iter_overeager_cloned.rs:11:20 + --> $DIR/iter_overeager_cloned.rs:12:20 | LL | let _: usize = vec.iter().filter(|x| x == &"2").cloned().count(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().filter(|x| x == &"2").count()` @@ -21,25 +21,25 @@ LL | let _: usize = vec.iter().filter(|x| x == &"2").cloned().count(); = note: `-D clippy::redundant-clone` implied by `-D warnings` error: called `cloned().take(...)` on an `Iterator`. It may be more efficient to call `take(...).cloned()` instead - --> $DIR/iter_overeager_cloned.rs:13:21 + --> $DIR/iter_overeager_cloned.rs:14:21 | LL | let _: Vec<_> = vec.iter().cloned().take(2).collect(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().take(2).cloned()` error: called `cloned().skip(...)` on an `Iterator`. It may be more efficient to call `skip(...).cloned()` instead - --> $DIR/iter_overeager_cloned.rs:15:21 + --> $DIR/iter_overeager_cloned.rs:16:21 | LL | let _: Vec<_> = vec.iter().cloned().skip(2).collect(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().skip(2).cloned()` error: called `cloned().nth(...)` on an `Iterator`. It may be more efficient to call `nth(...).cloned()` instead - --> $DIR/iter_overeager_cloned.rs:17:13 + --> $DIR/iter_overeager_cloned.rs:18:13 | LL | let _ = vec.iter().filter(|x| x == &"2").cloned().nth(2); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().filter(|x| x == &"2").nth(2).cloned()` error: called `cloned().flatten()` on an `Iterator`. It may be more efficient to call `flatten().cloned()` instead - --> $DIR/iter_overeager_cloned.rs:19:13 + --> $DIR/iter_overeager_cloned.rs:20:13 | LL | let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))] | _____________^