Use more efficient &&str to String conversion (clippy::inefficient_to_string)

Author: matthiaskrgr

src/librustc_builtin_macros/format.rs

@@ -284,7 +284,7 @@ impl<'a, 'b> Context<'a, 'b> {
                                 err.tool_only_span_suggestion(
                                     sp,
                                     &format!("use the `{}` trait", name),
-                                    fmt.to_string(),
+                                    (*fmt).to_string(),
                                     Applicability::MaybeIncorrect,
                                 );
                             }

src/librustc_codegen_llvm/asm.rs

@@ -60,7 +60,7 @@ impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
             .chain(ia.inputs.iter().map(|s| s.to_string()))
             .chain(ext_constraints)
             .chain(clobbers)
-            .chain(arch_clobbers.iter().map(|s| s.to_string()))
+            .chain(arch_clobbers.iter().map(|s| (*s).to_string()))
             .collect::<Vec<String>>()
             .join(",");
 

src/librustc_incremental/persist/dirty_clean.rs

@@ -343,7 +343,8 @@ impl DirtyCleanVisitor<'tcx> {
                 &format!("clean/dirty auto-assertions not yet defined for {:?}", node),
             ),
         };
-        let labels = Labels::from_iter(labels.iter().flat_map(|s| s.iter().map(|l| l.to_string())));
+        let labels =
+            Labels::from_iter(labels.iter().flat_map(|s| s.iter().map(|l| (*l).to_string())));
         (name, labels)
     }
 

src/librustc_lint/context.rs

@@ -369,7 +369,7 @@ impl LintStore {
                         return if *silent {
                             CheckLintNameResult::Ok(&lint_ids)
                         } else {
-                            CheckLintNameResult::Tool(Err((Some(&lint_ids), name.to_string())))
+                            CheckLintNameResult::Tool(Err((Some(&lint_ids), (*name).to_string())))
                         };
                     }
                     CheckLintNameResult::Ok(&lint_ids)
@@ -404,7 +404,7 @@ impl LintStore {
                         return if *silent {
                             CheckLintNameResult::Tool(Err((Some(&lint_ids), complete_name)))
                         } else {
-                            CheckLintNameResult::Tool(Err((Some(&lint_ids), name.to_string())))
+                            CheckLintNameResult::Tool(Err((Some(&lint_ids), (*name).to_string())))
                         };
                     }
                     CheckLintNameResult::Tool(Err((Some(&lint_ids), complete_name)))

src/librustc_typeck/collect.rs

@@ -151,7 +151,7 @@ crate fn placeholder_type_error(
         .unwrap_or(&"ParamName");
 
     let mut sugg: Vec<_> =
-        placeholder_types.iter().map(|sp| (*sp, type_name.to_string())).collect();
+        placeholder_types.iter().map(|sp| (*sp, (*type_name).to_string())).collect();
     if generics.is_empty() {
         sugg.push((span, format!("<{}>", type_name)));
     } else if let Some(arg) = generics.iter().find(|arg| match arg.name {
@@ -160,7 +160,7 @@ crate fn placeholder_type_error(
     }) {
         // Account for `_` already present in cases like `struct S<_>(_);` and suggest
         // `struct S<T>(T);` instead of `struct S<_, T>(T);`.
-        sugg.push((arg.span, type_name.to_string()));
+        sugg.push((arg.span, (*type_name).to_string()));
     } else {
         sugg.push((
             generics.iter().last().unwrap().span.shrink_to_hi(),