remove redundant clones

Author: matthiaskrgr

Diff for: compiler/rustc_parse/src/parser/diagnostics.rs

@@ -570,15 +570,13 @@ impl<'a> Parser<'a> {
         let expect = tokens_to_string(&expected);
         let actual = super::token_descr(&self.token);
         let (msg_exp, (label_sp, label_exp)) = if expected.len() > 1 {
+            let fmt = format!("expected one of {expect}, found {actual}");
             let short_expect = if expected.len() > 6 {
                 format!("{} possible tokens", expected.len())
             } else {
-                expect.clone()
+                expect
             };
-            (
-                format!("expected one of {expect}, found {actual}"),
-                (self.prev_token.span.shrink_to_hi(), format!("expected one of {short_expect}")),
-            )
+            (fmt, (self.prev_token.span.shrink_to_hi(), format!("expected one of {short_expect}")))
         } else if expected.is_empty() {
             (
                 format!("unexpected token: {actual}"),

Diff for: compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -2944,22 +2944,25 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             rustc_transmute::Answer::No(reason) => {
                 let dst = trait_ref.skip_binder().substs.type_at(0);
                 let src = trait_ref.skip_binder().substs.type_at(1);
-                let custom_err_msg = format!("`{src}` cannot be safely transmuted into `{dst}` in the defining scope of `{scope}`").to_string();
+                let custom_err_msg = format!(
+                    "`{src}` cannot be safely transmuted into `{dst}` in the defining scope of `{scope}`"
+                );
                 let reason_msg = match reason {
                     rustc_transmute::Reason::SrcIsUnspecified => {
-                        format!("`{src}` does not have a well-specified layout").to_string()
+                        format!("`{src}` does not have a well-specified layout")
                     }
+
                     rustc_transmute::Reason::DstIsUnspecified => {
-                        format!("`{dst}` does not have a well-specified layout").to_string()
+                        format!("`{dst}` does not have a well-specified layout")
                     }
+
                     rustc_transmute::Reason::DstIsBitIncompatible => {
                         format!("At least one value of `{src}` isn't a bit-valid value of `{dst}`")
-                            .to_string()
                     }
+
                     rustc_transmute::Reason::DstIsPrivate => format!(
                         "`{dst}` is or contains a type or field that is not visible in that scope"
-                    )
-                    .to_string(),
+                    ),
                     // FIXME(bryangarza): Include the number of bytes of src and dst
                     rustc_transmute::Reason::DstIsTooBig => {
                         format!("The size of `{src}` is smaller than the size of `{dst}`")