Use implicit captured format args

Author: Jon Gjengset

src/cargo/util/config/mod.rs

@@ -1182,7 +1182,7 @@ impl Config {
                 // parse the value as a toml_edit::Document, and check that the (single)
                 // inner-most table is set via dotted keys.
                 let doc: toml_edit::Document = arg.parse().with_context(|| {
-                    format!("failed to parse value from --config argument `{}` as a dotted key expression", arg)
+                    format!("failed to parse value from --config argument `{arg}` as a dotted key expression")
                 })?;
                 fn non_empty_decor(d: &toml_edit::Decor) -> bool {
                     d.prefix().map_or(false, |p| !p.trim().is_empty())
@@ -1204,67 +1204,62 @@ impl Config {
                                     || non_empty_decor(nt.decor())
                                 {
                                     bail!(
-                                        "--config argument `{}` \
-                                            includes non-whitespace decoration",
-                                        arg
+                                        "--config argument `{arg}` \
+                                            includes non-whitespace decoration"
                                     )
                                 }
                                 table = nt;
                             }
                             Item::Value(v) if v.is_inline_table() => {
                                 bail!(
-                                    "--config argument `{}` \
-                                    sets a value to an inline table, which is not accepted",
-                                    arg,
+                                    "--config argument `{arg}` \
+                                    sets a value to an inline table, which is not accepted"
                                 );
                             }
                             Item::Value(v) => {
                                 if non_empty_decor(v.decor()) {
                                     bail!(
-                                        "--config argument `{}` \
-                                            includes non-whitespace decoration",
-                                        arg
+                                        "--config argument `{arg}` \
+                                            includes non-whitespace decoration"
                                     )
                                 }
                                 got_to_value = true;
                                 break;
                             }
                             Item::ArrayOfTables(_) => {
                                 bail!(
-                                    "--config argument `{}` \
-                                    sets a value to an array of tables, which is not accepted",
-                                    arg,
+                                    "--config argument `{arg}` \
+                                    sets a value to an array of tables, which is not accepted"
                                 );
                             }
 
                             Item::None => {
-                                bail!("--config argument `{}` doesn't provide a value", arg)
+                                bail!("--config argument `{arg}` doesn't provide a value")
                             }
                         }
                     }
                     got_to_value
                 };
                 if !ok {
                     bail!(
-                        "--config argument `{}` was not a TOML dotted key expression (such as `build.jobs = 2`)",
-                        arg
+                        "--config argument `{arg}` was not a TOML dotted key expression (such as `build.jobs = 2`)"
                     );
                 }
 
                 let toml_v = toml::from_document(doc).with_context(|| {
-                    format!("failed to parse value from --config argument `{}`", arg)
+                    format!("failed to parse value from --config argument `{arg}`")
                 })?;
 
                 CV::from_toml(Definition::Cli, toml_v)
-                    .with_context(|| format!("failed to convert --config argument `{}`", arg))?
+                    .with_context(|| format!("failed to convert --config argument `{arg}`"))?
             };
             let mut seen = HashSet::new();
             let tmp_table = self
                 .load_includes(tmp_table, &mut seen)
                 .with_context(|| "failed to load --config include".to_string())?;
             loaded_args
                 .merge(tmp_table, true)
-                .with_context(|| format!("failed to merge --config argument `{}`", arg))?;
+                .with_context(|| format!("failed to merge --config argument `{arg}`"))?;
         }
         Ok(loaded_args)
     }