remove unnecessary to_string and String::new

clippy_lints/src/almost_complete_letter_range.rs

@@ -90,7 +90,7 @@ fn check_range(cx: &EarlyContext<'_>, span: Span, start: &Expr, end: &Expr, sugg
                     diag.span_suggestion(
                         span,
                         "use an inclusive range",
-                        sugg.to_owned(),
+                        sugg,
                         Applicability::MaybeIncorrect,
                     );
                 }

clippy_lints/src/as_underscore.rs

@@ -63,7 +63,7 @@ impl<'tcx> LateLintPass<'tcx> for AsUnderscore {
                     diag.span_suggestion(
                         ty.span,
                         "consider giving the type explicitly",
-                        format!("{}", ty_resolved),
+                        ty_resolved,
                         Applicability::MachineApplicable,
                     );
             }

clippy_lints/src/empty_structs_with_brackets.rs

@@ -44,7 +44,7 @@ impl EarlyLintPass for EmptyStructsWithBrackets {
                     diagnostic.span_suggestion_hidden(
                         span_after_ident,
                         "remove the brackets",
-                        ";".to_string(),
+                        ";",
                         Applicability::MachineApplicable);
                     },
             );

clippy_lints/src/large_const_arrays.rs

@@ -75,7 +75,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeConstArrays {
                         diag.span_suggestion(
                             sugg_span,
                             "make this a static item",
-                            "static".to_string(),
+                            "static",
                             Applicability::MachineApplicable,
                         );
                     }

clippy_lints/src/manual_async_fn.rs

@@ -86,7 +86,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualAsyncFn {
                                 diag.span_suggestion(
                                     block.span,
                                     "move the body of the async block to the enclosing function",
-                                    body_snip.to_string(),
+                                    body_snip,
                                     Applicability::MachineApplicable
                                 );
                             }

clippy_lints/src/matches/match_same_arms.rs

@@ -113,7 +113,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
                     diag.span_suggestion(
                         arm1.span,
                         "try removing the arm",
-                        String::new(),
+                        "",
                         Applicability::MaybeIncorrect,
                     )
                     .help("or try changing either arm body")

clippy_lints/src/methods/str_splitn.rs

@@ -176,13 +176,13 @@ fn check_manual_split_once_indirect(
             diag.span_suggestion(
                 first.span,
                 &remove_msg,
-                String::new(),
+                "",
                 app,
             );
             diag.span_suggestion(
                 second.span,
                 &remove_msg,
-                String::new(),
+                "",
                 app,
             );
         });

clippy_lints/src/methods/unnecessary_iter_cloned.rs

@@ -85,7 +85,7 @@ pub fn check_for_loop_iter(
                         match addr_of_expr.kind {
                             ExprKind::AddrOf(_, _, referent) => {
                                 let span = addr_of_expr.span.with_hi(referent.span.lo());
-                                diag.span_suggestion(span, "remove this `&`", String::new(), applicability);
+                                diag.span_suggestion(span, "remove this `&`", "", applicability);
                             }
                             _ => unreachable!(),
                         }

clippy_lints/src/needless_late_init.rs

@@ -318,7 +318,7 @@ fn check<'tcx>(
                         diag.span_suggestion(
                             usage.stmt.span.shrink_to_hi(),
                             "add a semicolon after the `if` expression",
-                            ";".to_string(),
+                            ";",
                             applicability,
                         );
                     }
@@ -353,7 +353,7 @@ fn check<'tcx>(
                         diag.span_suggestion(
                             usage.stmt.span.shrink_to_hi(),
                             "add a semicolon after the `match` expression",
-                            ";".to_string(),
+                            ";",
                             applicability,
                         );
                     }

clippy_lints/src/needless_pass_by_value.rs

@@ -258,7 +258,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
                                 diag.span_suggestion(
                                     input.span,
                                     "consider changing the type to",
-                                    "&str".to_string(),
+                                    "&str",
                                     Applicability::Unspecified,
                                 );
 

clippy_lints/src/redundant_clone.rs

@@ -255,7 +255,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClone {
                         diag.span_suggestion(
                             sugg_span,
                             "remove this",
-                            String::new(),
+                            "",
                             app,
                         );
                         if clone_usage.cloned_used {

clippy_lints/src/transmute/transmute_float_to_int.rs

@@ -55,7 +55,7 @@ pub(super) fn check<'tcx>(
                         sugg
                     };
 
-                    diag.span_suggestion(e.span, "consider using", sugg.to_string(), Applicability::Unspecified);
+                    diag.span_suggestion(e.span, "consider using", sugg, Applicability::Unspecified);
                 },
             );
             true

clippy_lints/src/transmute/transmute_ptr_to_ptr.rs

@@ -25,7 +25,7 @@ pub(super) fn check<'tcx>(
                 |diag| {
                     if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
                         let sugg = arg.as_ty(cx.tcx.mk_ptr(*to_ty));
-                        diag.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified);
+                        diag.span_suggestion(e.span, "try", sugg, Applicability::Unspecified);
                     }
                 },
             );

clippy_lints/src/transmute/transmute_ref_to_ref.rs

@@ -73,7 +73,7 @@ pub(super) fn check<'tcx>(
                             diag.span_suggestion(
                                 e.span,
                                 "try",
-                                sugg.to_string(),
+                                sugg,
                                 Applicability::Unspecified,
                             );
                         },

clippy_lints/src/transmute/useless_transmute.rs

@@ -46,7 +46,7 @@ pub(super) fn check<'tcx>(
                                 arg.as_ty(cx.tcx.mk_ptr(rty_and_mut)).as_ty(to_ty)
                             };
 
-                            diag.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified);
+                            diag.span_suggestion(e.span, "try", sugg, Applicability::Unspecified);
                         }
                     },
                 );
@@ -64,7 +64,7 @@ pub(super) fn check<'tcx>(
                         diag.span_suggestion(
                             e.span,
                             "try",
-                            arg.as_ty(&to_ty.to_string()).to_string(),
+                            arg.as_ty(&to_ty.to_string()),
                             Applicability::Unspecified,
                         );
                     }

clippy_utils/src/attrs.rs

@@ -92,7 +92,7 @@ pub fn get_attr<'a>(
                                 diag.span_suggestion(
                                     attr_segments[1].ident.span,
                                     "consider using",
-                                    new_name.to_string(),
+                                    new_name,
                                     Applicability::MachineApplicable,
                                 );
                                 diag.emit();