diff --git a/clippy_lints/src/booleans.rs b/clippy_lints/src/booleans.rs
index 455f0df7cd0..a08113bf9e6 100644
--- a/clippy_lints/src/booleans.rs
+++ b/clippy_lints/src/booleans.rs
@@ -441,7 +441,7 @@ impl<'a, 'tcx> NonminimalBoolVisitor<'a, 'tcx> {
                             diag.span_suggestions(
                                 e.span,
                                 "try",
-                                suggestions.into_iter(),
+                                suggestions,
                                 // nonminimal_bool can produce minimal but
                                 // not human readable expressions (#3141)
                                 Applicability::Unspecified,
diff --git a/clippy_lints/src/explicit_into_iter_fn_arg.rs b/clippy_lints/src/explicit_into_iter_fn_arg.rs
index 007a3f43449..a56d72f0dea 100644
--- a/clippy_lints/src/explicit_into_iter_fn_arg.rs
+++ b/clippy_lints/src/explicit_into_iter_fn_arg.rs
@@ -3,7 +3,7 @@ use clippy_utils::source::snippet;
 use clippy_utils::{get_parent_expr, is_trait_method};
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
-use rustc_hir::*;
+use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
diff --git a/clippy_lints/src/loops/manual_memcpy.rs b/clippy_lints/src/loops/manual_memcpy.rs
index d4c3f76b864..7d1f8ef29c8 100644
--- a/clippy_lints/src/loops/manual_memcpy.rs
+++ b/clippy_lints/src/loops/manual_memcpy.rs
@@ -51,7 +51,7 @@ pub(super) fn check<'tcx>(
                 iter_b = Some(get_assignment(body));
             }
 
-            let assignments = iter_a.into_iter().flatten().chain(iter_b.into_iter());
+            let assignments = iter_a.into_iter().flatten().chain(iter_b);
 
             let big_sugg = assignments
                 // The only statements in the for loops can be indexed assignments from
@@ -402,7 +402,7 @@ fn get_assignments<'a, 'tcx>(
             StmtKind::Local(..) | StmtKind::Item(..) => None,
             StmtKind::Expr(e) | StmtKind::Semi(e) => Some(e),
         })
-        .chain((*expr).into_iter())
+        .chain(*expr)
         .filter(move |e| {
             if let ExprKind::AssignOp(_, place, _) = e.kind {
                 path_to_local(place).map_or(false, |id| {