-use crate::utils::{is_copy, match_path, paths, span_note_and_lint};
-use rustc_hir::{Item, ItemKind};
+use clippy_utils::diagnostics::span_lint_and_note;
+use clippy_utils::ty::is_copy;
+use rustc_hir::{Impl, Item, ItemKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+use if_chain::if_chain;
declare_clippy_lint! {
- /// **What it does:** Checks for types that implement `Copy` as well as
+ /// ### What it does
+ /// Checks for types that implement `Copy` as well as
/// `Iterator`.
///
- /// **Why is this bad?** Implicit copies can be confusing when working with
+ /// ### Why is this bad?
+ /// Implicit copies can be confusing when working with
/// iterator combinators.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust,ignore
/// #[derive(Copy, Clone)]
/// struct Countdown(u8);
declare_lint_pass!(CopyIterator => [COPY_ITERATOR]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CopyIterator {
- fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
- if let ItemKind::Impl {
- of_trait: Some(ref trait_ref),
- ..
- } = item.kind
- {
- let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
-
- if is_copy(cx, ty) && match_path(&trait_ref.path, &paths::ITERATOR) {
- span_note_and_lint(
+impl<'tcx> LateLintPass<'tcx> for CopyIterator {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if_chain! {
+ if let ItemKind::Impl(Impl {
+ of_trait: Some(ref trait_ref),
+ ..
+ }) = item.kind;
+ let ty = cx.tcx.type_of(item.def_id);
+ if is_copy(cx, ty);
+ if let Some(trait_id) = trait_ref.trait_def_id();
+ if cx.tcx.is_diagnostic_item(sym::Iterator, trait_id);
+ then {
+ span_lint_and_note(
cx,
COPY_ITERATOR,
item.span,
"you are implementing `Iterator` on a `Copy` type",
- item.span,
+ None,
"consider implementing `IntoIterator` instead",
);
}