1 files changed, 18 insertions, 10 deletions
diff --git a/clippy_lints/src/methods/implicit_clone.rs b/clippy_lints/src/methods/implicit_clone.rs
index 1211e2f2bf7..81c42de145f 100644
--- a/clippy_lints/src/methods/implicit_clone.rs
+++ b/clippy_lints/src/methods/implicit_clone.rs
@@ -1,28 +1,36 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::{is_diag_item_method, is_diag_trait_item};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
-use rustc_hir::ExprKind;
 use rustc_lint::LateContext;
 use rustc_middle::ty::TyS;
-use rustc_span::symbol::Symbol;
+use rustc_span::{sym, Span};
 
 use super::IMPLICIT_CLONE;
-use clippy_utils::is_diagnostic_assoc_item;
 
-pub fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, trait_diagnostic: Symbol) {
+pub fn check(cx: &LateContext<'_>, method_name: &str, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, span: Span) {
     if_chain! {
-        if let ExprKind::MethodCall(method_path, _, [arg], _) = &expr.kind;
+        if let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
+        if match method_name {
+            "to_os_string" => is_diag_item_method(cx, method_def_id, sym::OsStr),
+            "to_owned" => is_diag_trait_item(cx, method_def_id, sym::ToOwned),
+            "to_path_buf" => is_diag_item_method(cx, method_def_id, sym::Path),
+            "to_vec" => cx.tcx.impl_of_method(method_def_id)
+                .map(|impl_did| Some(impl_did) == cx.tcx.lang_items().slice_alloc_impl())
+                == Some(true),
+            _ => false,
+        };
         let return_type = cx.typeck_results().expr_ty(expr);
-        let input_type = cx.typeck_results().expr_ty(arg).peel_refs();
-        if let Some(expr_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
+        let input_type = cx.typeck_results().expr_ty(recv).peel_refs();
         if let Some(ty_name) = input_type.ty_adt_def().map(|adt_def| cx.tcx.item_name(adt_def.did));
         if TyS::same_type(return_type, input_type);
-        if is_diagnostic_assoc_item(cx, expr_def_id, trait_diagnostic);
         then {
             span_lint_and_sugg(
-                cx,IMPLICIT_CLONE,method_path.ident.span,
-                &format!("implicitly cloning a `{}` by calling `{}` on its dereferenced type", ty_name, method_path.ident.name),
+                cx,
+                IMPLICIT_CLONE,
+                span,
+                &format!("implicitly cloning a `{}` by calling `{}` on its dereferenced type", ty_name, method_name),
                 "consider using",
                 "clone".to_string(),
                 Applicability::MachineApplicable