Apply uninlined_format-args to clippy_lints

This change is needed for the uninlined_format-args lint to be merged.
See https://github.com/rust-lang/rust-clippy/pull/9233

clippy_lints/src/approx_const.rs

@@ -92,7 +92,7 @@ impl ApproxConstant {
                         cx,
                         APPROX_CONSTANT,
                         e.span,
-                        &format!("approximate value of `{}::consts::{}` found", module, &name),
+                        &format!("approximate value of `{module}::consts::{}` found", &name),
                         None,
                         "consider using the constant directly",
                     );
@@ -126,7 +126,7 @@ fn is_approx_const(constant: f64, value: &str, min_digits: usize) -> bool {
         // The value is a truncated constant
         true
     } else {
-        let round_const = format!("{:.*}", value.len() - 2, constant);
+        let round_const = format!("{constant:.*}", value.len() - 2);
         value == round_const
     }
 }

clippy_lints/src/asm_syntax.rs

@@ -44,7 +44,7 @@ fn check_expr_asm_syntax(lint: &'static Lint, cx: &EarlyContext<'_>, expr: &Expr
                 cx,
                 lint,
                 expr.span,
-                &format!("{} x86 assembly syntax used", style),
+                &format!("{style} x86 assembly syntax used"),
                 None,
                 &format!("use {} x86 assembly syntax", !style),
             );

clippy_lints/src/assertions_on_constants.rs

@@ -60,9 +60,9 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
                 cx,
                 ASSERTIONS_ON_CONSTANTS,
                 macro_call.span,
-                &format!("`assert!(false{})` should probably be replaced", assert_arg),
+                &format!("`assert!(false{assert_arg})` should probably be replaced"),
                 None,
-                &format!("use `panic!({})` or `unreachable!({0})`", panic_arg),
+                &format!("use `panic!({panic_arg})` or `unreachable!({panic_arg})`"),
             );
         }
     }

clippy_lints/src/assertions_on_result_states.rs

@@ -69,9 +69,8 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
                         "called `assert!` with `Result::is_ok`",
                         "replace with",
                         format!(
-                            "{}.unwrap(){}",
-                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0,
-                            semicolon
+                            "{}.unwrap(){semicolon}",
+                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0
                         ),
                         app,
                     );
@@ -84,9 +83,8 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
                         "called `assert!` with `Result::is_err`",
                         "replace with",
                         format!(
-                            "{}.unwrap_err(){}",
-                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0,
-                            semicolon
+                            "{}.unwrap_err(){semicolon}",
+                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0
                         ),
                         app,
                     );

clippy_lints/src/attrs.rs

@@ -541,10 +541,7 @@ fn check_attrs(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribut
                     cx,
                     INLINE_ALWAYS,
                     attr.span,
-                    &format!(
-                        "you have declared `#[inline(always)]` on `{}`. This is usually a bad idea",
-                        name
-                    ),
+                    &format!("you have declared `#[inline(always)]` on `{name}`. This is usually a bad idea"),
                 );
             }
         }
@@ -720,7 +717,7 @@ fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) {
                 let mut unix_suggested = false;
 
                 for (os, span) in mismatched {
-                    let sugg = format!("target_os = \"{}\"", os);
+                    let sugg = format!("target_os = \"{os}\"");
                     diag.span_suggestion(span, "try", sugg, Applicability::MaybeIncorrect);
 
                     if !unix_suggested && is_unix(os) {

clippy_lints/src/bool_assert_comparison.rs

@@ -98,9 +98,9 @@ impl<'tcx> LateLintPass<'tcx> for BoolAssertComparison {
             cx,
             BOOL_ASSERT_COMPARISON,
             macro_call.span,
-            &format!("used `{}!` with a literal bool", macro_name),
+            &format!("used `{macro_name}!` with a literal bool"),
             "replace it with",
-            format!("{}!(..)", non_eq_mac),
+            format!("{non_eq_mac}!(..)"),
             Applicability::MaybeIncorrect,
         );
     }

clippy_lints/src/booleans.rs

@@ -263,9 +263,8 @@ fn simplify_not(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> {
             }
             .and_then(|op| {
                 Some(format!(
-                    "{}{}{}",
+                    "{}{op}{}",
                     snippet_opt(cx, lhs.span)?,
-                    op,
                     snippet_opt(cx, rhs.span)?
                 ))
             })
@@ -285,7 +284,7 @@ fn simplify_not(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> {
                     let path: &str = path.ident.name.as_str();
                     a == path
                 })
-                .and_then(|(_, neg_method)| Some(format!("{}.{}()", snippet_opt(cx, receiver.span)?, neg_method)))
+                .and_then(|(_, neg_method)| Some(format!("{}.{neg_method}()", snippet_opt(cx, receiver.span)?)))
         },
         _ => None,
     }

clippy_lints/src/cargo/common_metadata.rs

@@ -40,7 +40,7 @@ pub(super) fn check(cx: &LateContext<'_>, metadata: &Metadata, ignore_publish: b
 }
 
 fn missing_warning(cx: &LateContext<'_>, package: &cargo_metadata::Package, field: &str) {
-    let message = format!("package `{}` is missing `{}` metadata", package.name, field);
+    let message = format!("package `{}` is missing `{field}` metadata", package.name);
     span_lint(cx, CARGO_COMMON_METADATA, DUMMY_SP, &message);
 }
 

clippy_lints/src/cargo/feature_name.rs

@@ -57,10 +57,8 @@ fn lint(cx: &LateContext<'_>, feature: &str, substring: &str, is_prefix: bool) {
         },
         DUMMY_SP,
         &format!(
-            "the \"{}\" {} in the feature name \"{}\" is {}",
-            substring,
+            "the \"{substring}\" {} in the feature name \"{feature}\" is {}",
             if is_prefix { "prefix" } else { "suffix" },
-            feature,
             if is_negative { "negative" } else { "redundant" }
         ),
         None,

clippy_lints/src/cargo/mod.rs

@@ -196,7 +196,7 @@ impl LateLintPass<'_> for Cargo {
                 },
                 Err(e) => {
                     for lint in NO_DEPS_LINTS {
-                        span_lint(cx, lint, DUMMY_SP, &format!("could not read cargo metadata: {}", e));
+                        span_lint(cx, lint, DUMMY_SP, &format!("could not read cargo metadata: {e}"));
                     }
                 },
             }
@@ -212,7 +212,7 @@ impl LateLintPass<'_> for Cargo {
                 },
                 Err(e) => {
                     for lint in WITH_DEPS_LINTS {
-                        span_lint(cx, lint, DUMMY_SP, &format!("could not read cargo metadata: {}", e));
+                        span_lint(cx, lint, DUMMY_SP, &format!("could not read cargo metadata: {e}"));
                     }
                 },
             }

clippy_lints/src/cargo/multiple_crate_versions.rs

@@ -37,7 +37,7 @@ pub(super) fn check(cx: &LateContext<'_>, metadata: &Metadata) {
                         cx,
                         MULTIPLE_CRATE_VERSIONS,
                         DUMMY_SP,
-                        &format!("multiple versions for dependency `{}`: {}", name, versions),
+                        &format!("multiple versions for dependency `{name}`: {versions}"),
                     );
                 }
             }

clippy_lints/src/casts/borrow_as_ptr.rs

@@ -30,7 +30,7 @@ pub(super) fn check<'tcx>(
             expr.span,
             "borrow as raw pointer",
             "try",
-            format!("{}::ptr::{}!({})", core_or_std, macro_name, snip),
+            format!("{core_or_std}::ptr::{macro_name}!({snip})"),
             Applicability::MachineApplicable,
         );
     }

clippy_lints/src/casts/cast_lossless.rs

@@ -41,15 +41,9 @@ pub(super) fn check(
     );
 
     let message = if cast_from.is_bool() {
-        format!(
-            "casting `{0:}` to `{1:}` is more cleanly stated with `{1:}::from(_)`",
-            cast_from, cast_to
-        )
+        format!("casting `{cast_from:}` to `{cast_to:}` is more cleanly stated with `{cast_to:}::from(_)`")
     } else {
-        format!(
-            "casting `{}` to `{}` may become silently lossy if you later change the type",
-            cast_from, cast_to
-        )
+        format!("casting `{cast_from}` to `{cast_to}` may become silently lossy if you later change the type")
     };
 
     span_lint_and_sugg(
@@ -58,7 +52,7 @@ pub(super) fn check(
         expr.span,
         &message,
         "try",
-        format!("{}::from({})", cast_to, sugg),
+        format!("{cast_to}::from({sugg})"),
         applicability,
     );
 }

clippy_lints/src/casts/cast_possible_truncation.rs

@@ -103,10 +103,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                 return;
             }
 
-            format!(
-                "casting `{}` to `{}` may truncate the value{}",
-                cast_from, cast_to, suffix,
-            )
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value{suffix}",)
         },
 
         (ty::Adt(def, _), true) if def.is_enum() => {
@@ -142,20 +139,17 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                     CAST_ENUM_TRUNCATION,
                     expr.span,
                     &format!(
-                        "casting `{}::{}` to `{}` will truncate the value{}",
-                        cast_from, variant.name, cast_to, suffix,
+                        "casting `{cast_from}::{}` to `{cast_to}` will truncate the value{suffix}",
+                        variant.name,
                     ),
                 );
                 return;
             }
-            format!(
-                "casting `{}` to `{}` may truncate the value{}",
-                cast_from, cast_to, suffix,
-            )
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value{suffix}",)
         },
 
         (ty::Float(_), true) => {
-            format!("casting `{}` to `{}` may truncate the value", cast_from, cast_to)
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value")
         },
 
         (ty::Float(FloatTy::F64), false) if matches!(cast_to.kind(), &ty::Float(FloatTy::F32)) => {

clippy_lints/src/casts/cast_possible_wrap.rs

@@ -35,10 +35,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_from: Ty<'_>, ca
             cx,
             CAST_POSSIBLE_WRAP,
             expr.span,
-            &format!(
-                "casting `{}` to `{}` may wrap around the value{}",
-                cast_from, cast_to, suffix,
-            ),
+            &format!("casting `{cast_from}` to `{cast_to}` may wrap around the value{suffix}",),
         );
     }
 }

clippy_lints/src/casts/cast_ptr_alignment.rs

@@ -49,9 +49,7 @@ fn lint_cast_ptr_alignment<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, cast_f
             CAST_PTR_ALIGNMENT,
             expr.span,
             &format!(
-                "casting from `{}` to a more-strictly-aligned pointer (`{}`) ({} < {} bytes)",
-                cast_from,
-                cast_to,
+                "casting from `{cast_from}` to a more-strictly-aligned pointer (`{cast_to}`) ({} < {} bytes)",
                 from_layout.align.abi.bytes(),
                 to_layout.align.abi.bytes(),
             ),

clippy_lints/src/casts/cast_sign_loss.rs

@@ -14,10 +14,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_op: &Expr<'_>, c
             cx,
             CAST_SIGN_LOSS,
             expr.span,
-            &format!(
-                "casting `{}` to `{}` may lose the sign of the value",
-                cast_from, cast_to
-            ),
+            &format!("casting `{cast_from}` to `{cast_to}` may lose the sign of the value"),
         );
     }
 }

clippy_lints/src/casts/cast_slice_different_sizes.rs

@@ -35,8 +35,8 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, msrv: Optio
                     CAST_SLICE_DIFFERENT_SIZES,
                     expr.span,
                     &format!(
-                        "casting between raw pointers to `[{}]` (element size {}) and `[{}]` (element size {}) does not adjust the count",
-                        start_ty.ty, from_size, end_ty.ty, to_size,
+                        "casting between raw pointers to `[{}]` (element size {from_size}) and `[{}]` (element size {to_size}) does not adjust the count",
+                        start_ty.ty, end_ty.ty,
                     ),
                     |diag| {
                         let ptr_snippet = source::snippet(cx, left_cast.span, "..");

clippy_lints/src/casts/char_lit_as_u8.rs

@@ -31,7 +31,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
                         diag.span_suggestion(
                             expr.span,
                             "use a byte literal instead",
-                            format!("b{}", snippet),
+                            format!("b{snippet}"),
                             applicability,
                         );
                     }

clippy_lints/src/casts/fn_to_numeric_cast.rs

@@ -25,9 +25,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                     cx,
                     FN_TO_NUMERIC_CAST,
                     expr.span,
-                    &format!("casting function pointer `{}` to `{}`", from_snippet, cast_to),
+                    &format!("casting function pointer `{from_snippet}` to `{cast_to}`"),
                     "try",
-                    format!("{} as usize", from_snippet),
+                    format!("{from_snippet} as usize"),
                     applicability,
                 );
             }

clippy_lints/src/casts/fn_to_numeric_cast_any.rs

@@ -23,9 +23,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                 cx,
                 FN_TO_NUMERIC_CAST_ANY,
                 expr.span,
-                &format!("casting function pointer `{}` to `{}`", from_snippet, cast_to),
+                &format!("casting function pointer `{from_snippet}` to `{cast_to}`"),
                 "did you mean to invoke the function?",
-                format!("{}() as {}", from_snippet, cast_to),
+                format!("{from_snippet}() as {cast_to}"),
                 applicability,
             );
         },

clippy_lints/src/casts/fn_to_numeric_cast_with_truncation.rs

@@ -24,12 +24,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                     cx,
                     FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
                     expr.span,
-                    &format!(
-                        "casting function pointer `{}` to `{}`, which truncates the value",
-                        from_snippet, cast_to
-                    ),
+                    &format!("casting function pointer `{from_snippet}` to `{cast_to}`, which truncates the value"),
                     "try",
-                    format!("{} as usize", from_snippet),
+                    format!("{from_snippet} as usize"),
                     applicability,
                 );
             }

clippy_lints/src/casts/ptr_as_ptr.rs

@@ -33,7 +33,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Option<RustcVer
             let turbofish = match &cast_to_hir_ty.kind {
                     TyKind::Infer => Cow::Borrowed(""),
                     TyKind::Ptr(mut_ty) if matches!(mut_ty.ty.kind, TyKind::Infer) => Cow::Borrowed(""),
-                    _ => Cow::Owned(format!("::<{}>", to_pointee_ty)),
+                    _ => Cow::Owned(format!("::<{to_pointee_ty}>")),
                 };
             span_lint_and_sugg(
                 cx,
@@ -41,7 +41,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Option<RustcVer
                 expr.span,
                 "`as` casting between raw pointers without changing its mutability",
                 "try `pointer::cast`, a safer alternative",
-                format!("{}.cast{}()", cast_expr_sugg.maybe_par(), turbofish),
+                format!("{}.cast{turbofish}()", cast_expr_sugg.maybe_par()),
                 applicability,
             );
         }

clippy_lints/src/casts/unnecessary_cast.rs

@@ -71,10 +71,7 @@ pub(super) fn check<'tcx>(
                         cx,
                         UNNECESSARY_CAST,
                         expr.span,
-                        &format!(
-                            "casting to the same type is unnecessary (`{}` -> `{}`)",
-                            cast_from, cast_to
-                        ),
+                        &format!("casting to the same type is unnecessary (`{cast_from}` -> `{cast_to}`)"),
                         "try",
                         literal_str,
                         Applicability::MachineApplicable,
@@ -101,9 +98,9 @@ fn lint_unnecessary_cast(cx: &LateContext<'_>, expr: &Expr<'_>, literal_str: &st
         cx,
         UNNECESSARY_CAST,
         expr.span,
-        &format!("casting {} literal to `{}` is unnecessary", literal_kind_name, cast_to),
+        &format!("casting {literal_kind_name} literal to `{cast_to}` is unnecessary"),
         "try",
-        format!("{}_{}", matchless.trim_end_matches('.'), cast_to),
+        format!("{}_{cast_to}", matchless.trim_end_matches('.')),
         Applicability::MachineApplicable,
     );
 }

clippy_lints/src/checked_conversions.rs

@@ -82,7 +82,7 @@ impl<'tcx> LateLintPass<'tcx> for CheckedConversions {
                     item.span,
                     "checked cast can be simplified",
                     "try",
-                    format!("{}::try_from({}).is_ok()", to_type, snippet),
+                    format!("{to_type}::try_from({snippet}).is_ok()"),
                     applicability,
                 );
             }

clippy_lints/src/cognitive_complexity.rs

@@ -107,8 +107,7 @@ impl CognitiveComplexity {
                 COGNITIVE_COMPLEXITY,
                 fn_span,
                 &format!(
-                    "the function has a cognitive complexity of ({}/{})",
-                    rust_cc,
+                    "the function has a cognitive complexity of ({rust_cc}/{})",
                     self.limit.limit()
                 ),
                 None,

clippy_lints/src/default.rs

@@ -105,7 +105,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
                     cx,
                     DEFAULT_TRAIT_ACCESS,
                     expr.span,
-                    &format!("calling `{}` is more clear than this expression", replacement),
+                    &format!("calling `{replacement}` is more clear than this expression"),
                     "try",
                     replacement,
                     Applicability::Unspecified, // First resolve the TODO above
@@ -210,7 +210,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
                     .map(|(field, rhs)| {
                         // extract and store the assigned value for help message
                         let value_snippet = snippet_with_macro_callsite(cx, rhs.span, "..");
-                        format!("{}: {}", field, value_snippet)
+                        format!("{field}: {value_snippet}")
                     })
                     .collect::<Vec<String>>()
                     .join(", ");
@@ -227,7 +227,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
                             .map(ToString::to_string)
                             .collect::<Vec<_>>()
                             .join(", ");
-                        format!("{}::<{}>", adt_def_ty_name, &tys_str)
+                        format!("{adt_def_ty_name}::<{}>", &tys_str)
                     } else {
                         binding_type.to_string()
                     }
@@ -235,12 +235,12 @@ impl<'tcx> LateLintPass<'tcx> for Default {
 
                 let sugg = if ext_with_default {
                     if field_list.is_empty() {
-                        format!("{}::default()", binding_type)
+                        format!("{binding_type}::default()")
                     } else {
-                        format!("{} {{ {}, ..Default::default() }}", binding_type, field_list)
+                        format!("{binding_type} {{ {field_list}, ..Default::default() }}")
                     }
                 } else {
-                    format!("{} {{ {} }}", binding_type, field_list)
+                    format!("{binding_type} {{ {field_list} }}")
                 };
 
                 // span lint once per statement that binds default
@@ -250,10 +250,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
                     first_assign.unwrap().span,
                     "field assignment outside of initializer for an instance created with Default::default()",
                     Some(local.span),
-                    &format!(
-                        "consider initializing the variable with `{}` and removing relevant reassignments",
-                        sugg
-                    ),
+                    &format!("consider initializing the variable with `{sugg}` and removing relevant reassignments"),
                 );
                 self.reassigned_linted.insert(span);
             }

clippy_lints/src/default_numeric_fallback.rs

@@ -95,8 +95,8 @@ impl<'a, 'tcx> NumericFallbackVisitor<'a, 'tcx> {
                         src
                     } else {
                         match lit.node {
-                            LitKind::Int(src, _) => format!("{}", src),
-                            LitKind::Float(src, _) => format!("{}", src),
+                            LitKind::Int(src, _) => format!("{src}"),
+                            LitKind::Float(src, _) => format!("{src}"),
                             _ => return,
                         }
                     };

clippy_lints/src/dereference.rs

@@ -1308,7 +1308,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data
             };
 
             let expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence().order() < PREC_PREFIX {
-                format!("({})", expr_str)
+                format!("({expr_str})")
             } else {
                 expr_str.into_owned()
             };
@@ -1322,7 +1322,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data
                     Mutability::Mut => "explicit `deref_mut` method call",
                 },
                 "try this",
-                format!("{}{}{}", addr_of_str, deref_str, expr_str),
+                format!("{addr_of_str}{deref_str}{expr_str}"),
                 app,
             );
         },
@@ -1336,7 +1336,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data
                     && !has_enclosing_paren(&snip)
                     && (expr.precedence().order() < data.position.precedence() || calls_field)
                 {
-                    format!("({})", snip)
+                    format!("({snip})")
                 } else {
                     snip.into()
                 };
@@ -1379,9 +1379,9 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data
                     let (snip, snip_is_macro) = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app);
                     let sugg =
                         if !snip_is_macro && expr.precedence().order() < precedence && !has_enclosing_paren(&snip) {
-                            format!("{}({})", prefix, snip)
+                            format!("{prefix}({snip})")
                         } else {
-                            format!("{}{}", prefix, snip)
+                            format!("{prefix}{snip}")
                         };
                     diag.span_suggestion(data.span, "try this", sugg, app);
                 },
@@ -1460,14 +1460,14 @@ impl Dereferencing {
                             } else {
                                 pat.always_deref = false;
                                 let snip = snippet_with_context(cx, e.span, parent.span.ctxt(), "..", &mut pat.app).0;
-                                pat.replacements.push((e.span, format!("&{}", snip)));
+                                pat.replacements.push((e.span, format!("&{snip}")));
                             }
                         },
                         _ if !e.span.from_expansion() => {
                             // Double reference might be needed at this point.
                             pat.always_deref = false;
                             let snip = snippet_with_applicability(cx, e.span, "..", &mut pat.app);
-                            pat.replacements.push((e.span, format!("&{}", snip)));
+                            pat.replacements.push((e.span, format!("&{snip}")));
                         },
                         // Edge case for macros. The span of the identifier will usually match the context of the
                         // binding, but not if the identifier was created in a macro. e.g. `concat_idents` and proc

clippy_lints/src/disallowed_methods.rs

@@ -106,7 +106,7 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedMethods {
                 reason: Some(reason), ..
             } = conf
             {
-                diag.note(&format!("{} (from clippy.toml)", reason));
+                diag.note(&format!("{reason} (from clippy.toml)"));
             }
         });
     }

clippy_lints/src/disallowed_script_idents.rs

@@ -99,8 +99,7 @@ impl EarlyLintPass for DisallowedScriptIdents {
                         DISALLOWED_SCRIPT_IDENTS,
                         span,
                         &format!(
-                            "identifier `{}` has a Unicode script that is not allowed by configuration: {}",
-                            symbol_str,
+                            "identifier `{symbol_str}` has a Unicode script that is not allowed by configuration: {}",
                             script.full_name()
                         ),
                     );

clippy_lints/src/disallowed_types.rs

@@ -92,7 +92,7 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedTypes {
                 conf::DisallowedType::Simple(path) => (path, None),
                 conf::DisallowedType::WithReason { path, reason } => (
                     path,
-                    reason.as_ref().map(|reason| format!("{} (from clippy.toml)", reason)),
+                    reason.as_ref().map(|reason| format!("{reason} (from clippy.toml)")),
                 ),
             };
             let segs: Vec<_> = path.split("::").collect();
@@ -130,7 +130,7 @@ fn emit(cx: &LateContext<'_>, name: &str, span: Span, reason: Option<&str>) {
         cx,
         DISALLOWED_TYPES,
         span,
-        &format!("`{}` is not allowed according to config", name),
+        &format!("`{name}` is not allowed according to config"),
         |diag| {
             if let Some(reason) = reason {
                 diag.note(reason);

clippy_lints/src/doc.rs

@@ -790,7 +790,7 @@ fn check_word(cx: &LateContext<'_>, word: &str, span: Span) {
                 diag.span_suggestion_with_style(
                     span,
                     "try",
-                    format!("`{}`", snippet),
+                    format!("`{snippet}`"),
                     applicability,
                     // always show the suggestion in a separate line, since the
                     // inline presentation adds another pair of backticks

clippy_lints/src/drop_forget_ref.rs

@@ -236,7 +236,7 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetRef {
                 expr.span,
                 msg,
                 Some(arg.span),
-                &format!("argument has type `{}`", arg_ty),
+                &format!("argument has type `{arg_ty}`"),
             );
         }
     }

clippy_lints/src/entry.rs

@@ -113,13 +113,8 @@ impl<'tcx> LateLintPass<'tcx> for HashMapPass {
                     ),
                 };
                 format!(
-                    "if let {}::{} = {}.entry({}) {} else {}",
+                    "if let {}::{entry_kind} = {map_str}.entry({key_str}) {then_str} else {else_str}",
                     map_ty.entry_path(),
-                    entry_kind,
-                    map_str,
-                    key_str,
-                    then_str,
-                    else_str,
                 )
             } else {
                 // if .. { insert } else { insert }
@@ -137,16 +132,11 @@ impl<'tcx> LateLintPass<'tcx> for HashMapPass {
                 let indent_str = snippet_indent(cx, expr.span);
                 let indent_str = indent_str.as_deref().unwrap_or("");
                 format!(
-                    "match {}.entry({}) {{\n{indent}    {entry}::{} => {}\n\
-                        {indent}    {entry}::{} => {}\n{indent}}}",
-                    map_str,
-                    key_str,
-                    then_entry,
+                    "match {map_str}.entry({key_str}) {{\n{indent_str}    {entry}::{then_entry} => {}\n\
+                        {indent_str}    {entry}::{else_entry} => {}\n{indent_str}}}",
                     reindent_multiline(then_str.into(), true, Some(4 + indent_str.len())),
-                    else_entry,
                     reindent_multiline(else_str.into(), true, Some(4 + indent_str.len())),
                     entry = map_ty.entry_path(),
-                    indent = indent_str,
                 )
             }
         } else {
@@ -163,20 +153,16 @@ impl<'tcx> LateLintPass<'tcx> for HashMapPass {
                     then_search.snippet_occupied(cx, then_expr.span, &mut app)
                 };
                 format!(
-                    "if let {}::{} = {}.entry({}) {}",
+                    "if let {}::{entry_kind} = {map_str}.entry({key_str}) {body_str}",
                     map_ty.entry_path(),
-                    entry_kind,
-                    map_str,
-                    key_str,
-                    body_str,
                 )
             } else if let Some(insertion) = then_search.as_single_insertion() {
                 let value_str = snippet_with_context(cx, insertion.value.span, then_expr.span.ctxt(), "..", &mut app).0;
                 if contains_expr.negated {
                     if insertion.value.can_have_side_effects() {
-                        format!("{}.entry({}).or_insert_with(|| {});", map_str, key_str, value_str)
+                        format!("{map_str}.entry({key_str}).or_insert_with(|| {value_str});")
                     } else {
-                        format!("{}.entry({}).or_insert({});", map_str, key_str, value_str)
+                        format!("{map_str}.entry({key_str}).or_insert({value_str});")
                     }
                 } else {
                     // TODO: suggest using `if let Some(v) = map.get_mut(k) { .. }` here.
@@ -186,7 +172,7 @@ impl<'tcx> LateLintPass<'tcx> for HashMapPass {
             } else {
                 let block_str = then_search.snippet_closure(cx, then_expr.span, &mut app);
                 if contains_expr.negated {
-                    format!("{}.entry({}).or_insert_with(|| {});", map_str, key_str, block_str)
+                    format!("{map_str}.entry({key_str}).or_insert_with(|| {block_str});")
                 } else {
                     // TODO: suggest using `if let Some(v) = map.get_mut(k) { .. }` here.
                     // This would need to be a different lint.

clippy_lints/src/enum_variants.rs

@@ -202,12 +202,11 @@ fn check_variant(cx: &LateContext<'_>, threshold: u64, def: &EnumDef<'_>, item_n
         cx,
         ENUM_VARIANT_NAMES,
         span,
-        &format!("all variants have the same {}fix: `{}`", what, value),
+        &format!("all variants have the same {what}fix: `{value}`"),
         None,
         &format!(
-            "remove the {}fixes and use full paths to \
-             the variants instead of glob imports",
-            what
+            "remove the {what}fixes and use full paths to \
+             the variants instead of glob imports"
         ),
     );
 }

clippy_lints/src/equatable_if_let.rs

@@ -91,9 +91,8 @@ impl<'tcx> LateLintPass<'tcx> for PatternEquality {
                     "this pattern matching can be expressed using equality",
                     "try",
                     format!(
-                        "{} == {}",
+                        "{} == {pat_str}",
                         snippet_with_context(cx, let_expr.init.span, expr.span.ctxt(), "..", &mut applicability).0,
-                        pat_str,
                     ),
                     applicability,
                 );

clippy_lints/src/eta_reduction.rs

@@ -130,7 +130,7 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
 
                             then {
                                 // Mutable closure is used after current expr; we cannot consume it.
-                                snippet = format!("&mut {}", snippet);
+                                snippet = format!("&mut {snippet}");
                             }
                         }
                         diag.span_suggestion(
@@ -158,7 +158,7 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
                     diag.span_suggestion(
                         expr.span,
                         "replace the closure with the method itself",
-                        format!("{}::{}", name, path.ident.name),
+                        format!("{name}::{}", path.ident.name),
                         Applicability::MachineApplicable,
                     );
                 })

clippy_lints/src/exhaustive_items.rs

@@ -97,7 +97,7 @@ impl LateLintPass<'_> for ExhaustiveItems {
                     item.span,
                     msg,
                     |diag| {
-                        let sugg = format!("#[non_exhaustive]\n{}", indent);
+                        let sugg = format!("#[non_exhaustive]\n{indent}");
                         diag.span_suggestion(suggestion_span,
                                              "try adding #[non_exhaustive]",
                                              sugg,

clippy_lints/src/explicit_write.rs

@@ -80,12 +80,12 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitWrite {
                 // used.
                 let (used, sugg_mac) = if let Some(macro_name) = calling_macro {
                     (
-                        format!("{}!({}(), ...)", macro_name, dest_name),
+                        format!("{macro_name}!({dest_name}(), ...)"),
                         macro_name.replace("write", "print"),
                     )
                 } else {
                     (
-                        format!("{}().write_fmt(...)", dest_name),
+                        format!("{dest_name}().write_fmt(...)"),
                         "print".into(),
                     )
                 };
@@ -100,9 +100,9 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitWrite {
                     cx,
                     EXPLICIT_WRITE,
                     expr.span,
-                    &format!("use of `{}.unwrap()`", used),
+                    &format!("use of `{used}.unwrap()`"),
                     "try this",
-                    format!("{}{}!({})", prefix, sugg_mac, inputs_snippet),
+                    format!("{prefix}{sugg_mac}!({inputs_snippet})"),
                     applicability,
                 )
             }

clippy_lints/src/float_literal.rs

@@ -173,9 +173,9 @@ impl FloatFormat {
         T: fmt::UpperExp + fmt::LowerExp + fmt::Display,
     {
         match self {
-            Self::LowerExp => format!("{:e}", f),
-            Self::UpperExp => format!("{:E}", f),
-            Self::Normal => format!("{}", f),
+            Self::LowerExp => format!("{f:e}"),
+            Self::UpperExp => format!("{f:E}"),
+            Self::Normal => format!("{f}"),
         }
     }
 }

clippy_lints/src/floating_point_arithmetic.rs

@@ -142,8 +142,7 @@ fn prepare_receiver_sugg<'a>(cx: &LateContext<'_>, mut expr: &'a Expr<'a>) -> Su
         if let ast::LitKind::Float(sym, ast::LitFloatType::Unsuffixed) = lit.node;
         then {
             let op = format!(
-                "{}{}{}",
-                suggestion,
+                "{suggestion}{}{}",
                 // Check for float literals without numbers following the decimal
                 // separator such as `2.` and adds a trailing zero
                 if sym.as_str().ends_with('.') {
@@ -172,7 +171,7 @@ fn check_log_base(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>, ar
             expr.span,
             "logarithm for bases 2, 10 and e can be computed more accurately",
             "consider using",
-            format!("{}.{}()", Sugg::hir(cx, receiver, "..").maybe_par(), method),
+            format!("{}.{method}()", Sugg::hir(cx, receiver, "..").maybe_par()),
             Applicability::MachineApplicable,
         );
     }
@@ -251,7 +250,7 @@ fn check_powf(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>, args:
                 expr.span,
                 "exponent for bases 2 and e can be computed more accurately",
                 "consider using",
-                format!("{}.{}()", prepare_receiver_sugg(cx, &args[0]), method),
+                format!("{}.{method}()", prepare_receiver_sugg(cx, &args[0])),
                 Applicability::MachineApplicable,
             );
         }

clippy_lints/src/format.rs

@@ -62,7 +62,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessFormat {
                 [_] => {
                     // Simulate macro expansion, converting {{ and }} to { and }.
                     let s_expand = format_args.format_string.snippet.replace("{{", "{").replace("}}", "}");
-                    let sugg = format!("{}.to_string()", s_expand);
+                    let sugg = format!("{s_expand}.to_string()");
                     span_useless_format(cx, call_site, sugg, applicability);
                 },
                 [..] => {},

clippy_lints/src/format_args.rs

@@ -112,11 +112,10 @@ fn check_format_in_format_args(cx: &LateContext<'_>, call_site: Span, name: Symb
         cx,
         FORMAT_IN_FORMAT_ARGS,
         call_site,
-        &format!("`format!` in `{}!` args", name),
+        &format!("`format!` in `{name}!` args"),
         |diag| {
             diag.help(&format!(
-                "combine the `format!(..)` arguments with the outer `{}!(..)` call",
-                name
+                "combine the `format!(..)` arguments with the outer `{name}!(..)` call"
             ));
             diag.help("or consider changing `format!` to `format_args!`");
         },
@@ -144,8 +143,7 @@ fn check_to_string_in_format_args(cx: &LateContext<'_>, name: Symbol, value: &Ex
                     TO_STRING_IN_FORMAT_ARGS,
                     value.span.with_lo(receiver.span.hi()),
                     &format!(
-                        "`to_string` applied to a type that implements `Display` in `{}!` args",
-                        name
+                        "`to_string` applied to a type that implements `Display` in `{name}!` args"
                     ),
                     "remove this",
                     String::new(),
@@ -157,16 +155,13 @@ fn check_to_string_in_format_args(cx: &LateContext<'_>, name: Symbol, value: &Ex
                     TO_STRING_IN_FORMAT_ARGS,
                     value.span,
                     &format!(
-                        "`to_string` applied to a type that implements `Display` in `{}!` args",
-                        name
+                        "`to_string` applied to a type that implements `Display` in `{name}!` args"
                     ),
                     "use this",
                     format!(
-                        "{}{:*>width$}{}",
+                        "{}{:*>n_needed_derefs$}{receiver_snippet}",
                         if needs_ref { "&" } else { "" },
-                        "",
-                        receiver_snippet,
-                        width = n_needed_derefs
+                        ""
                     ),
                     Applicability::MachineApplicable,
                 );

clippy_lints/src/format_impl.rs

@@ -214,12 +214,12 @@ fn check_print_in_format_impl(cx: &LateContext<'_>, expr: &Expr<'_>, impl_trait:
                 cx,
                 PRINT_IN_FORMAT_IMPL,
                 macro_call.span,
-                &format!("use of `{}!` in `{}` impl", name, impl_trait.name),
+                &format!("use of `{name}!` in `{}` impl", impl_trait.name),
                 "replace with",
                 if let Some(formatter_name) = impl_trait.formatter_name {
-                    format!("{}!({}, ..)", replacement, formatter_name)
+                    format!("{replacement}!({formatter_name}, ..)")
                 } else {
-                    format!("{}!(..)", replacement)
+                    format!("{replacement}!(..)")
                 },
                 Applicability::HasPlaceholders,
             );

clippy_lints/src/formatting.rs

@@ -154,11 +154,10 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) {
                             eqop_span,
                             &format!(
                                 "this looks like you are trying to use `.. {op}= ..`, but you \
-                                 really are doing `.. = ({op} ..)`",
-                                op = op
+                                 really are doing `.. = ({op} ..)`"
                             ),
                             None,
-                            &format!("to remove this lint, use either `{op}=` or `= {op}`", op = op),
+                            &format!("to remove this lint, use either `{op}=` or `= {op}`"),
                         );
                     }
                 }
@@ -191,16 +190,12 @@ fn check_unop(cx: &EarlyContext<'_>, expr: &Expr) {
                 SUSPICIOUS_UNARY_OP_FORMATTING,
                 eqop_span,
                 &format!(
-                    "by not having a space between `{binop}` and `{unop}` it looks like \
-                     `{binop}{unop}` is a single operator",
-                    binop = binop_str,
-                    unop = unop_str
+                    "by not having a space between `{binop_str}` and `{unop_str}` it looks like \
+                     `{binop_str}{unop_str}` is a single operator"
                 ),
                 None,
                 &format!(
-                    "put a space between `{binop}` and `{unop}` and remove the space after `{unop}`",
-                    binop = binop_str,
-                    unop = unop_str
+                    "put a space between `{binop_str}` and `{unop_str}` and remove the space after `{unop_str}`"
                 ),
             );
         }
@@ -246,12 +241,11 @@ fn check_else(cx: &EarlyContext<'_>, expr: &Expr) {
                 cx,
                 SUSPICIOUS_ELSE_FORMATTING,
                 else_span,
-                &format!("this is an `else {}` but the formatting might hide it", else_desc),
+                &format!("this is an `else {else_desc}` but the formatting might hide it"),
                 None,
                 &format!(
                     "to remove this lint, remove the `else` or remove the new line between \
-                     `else` and `{}`",
-                    else_desc,
+                     `else` and `{else_desc}`",
                 ),
             );
         }
@@ -320,11 +314,10 @@ fn check_missing_else(cx: &EarlyContext<'_>, first: &Expr, second: &Expr) {
                 cx,
                 SUSPICIOUS_ELSE_FORMATTING,
                 else_span,
-                &format!("this looks like {} but the `else` is missing", looks_like),
+                &format!("this looks like {looks_like} but the `else` is missing"),
                 None,
                 &format!(
-                    "to remove this lint, add the missing `else` or add a new line before {}",
-                    next_thing,
+                    "to remove this lint, add the missing `else` or add a new line before {next_thing}",
                 ),
             );
         }

clippy_lints/src/from_str_radix_10.rs

@@ -88,7 +88,7 @@ impl<'tcx> LateLintPass<'tcx> for FromStrRadix10 {
                     exp.span,
                     "this call to `from_str_radix` can be replaced with a call to `str::parse`",
                     "try",
-                    format!("{}.parse::<{}>()", sugg, prim_ty.name_str()),
+                    format!("{sugg}.parse::<{}>()", prim_ty.name_str()),
                     Applicability::MaybeIncorrect
                 );
             }

clippy_lints/src/functions/must_use.rs

@@ -143,7 +143,7 @@ fn check_must_use_candidate<'tcx>(
             diag.span_suggestion(
                 fn_span,
                 "add the attribute",
-                format!("#[must_use] {}", snippet),
+                format!("#[must_use] {snippet}"),
                 Applicability::MachineApplicable,
             );
         }

clippy_lints/src/functions/too_many_arguments.rs

@@ -59,10 +59,7 @@ fn check_arg_number(cx: &LateContext<'_>, decl: &hir::FnDecl<'_>, fn_span: Span,
             cx,
             TOO_MANY_ARGUMENTS,
             fn_span,
-            &format!(
-                "this function has too many arguments ({}/{})",
-                args, too_many_arguments_threshold
-            ),
+            &format!("this function has too many arguments ({args}/{too_many_arguments_threshold})"),
         );
     }
 }

clippy_lints/src/functions/too_many_lines.rs

@@ -78,10 +78,7 @@ pub(super) fn check_fn(
             cx,
             TOO_MANY_LINES,
             span,
-            &format!(
-                "this function has too many lines ({}/{})",
-                line_count, too_many_lines_threshold
-            ),
+            &format!("this function has too many lines ({line_count}/{too_many_lines_threshold})"),
         );
     }
 }

clippy_lints/src/if_then_some_else_none.rs

@@ -84,7 +84,7 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
         {
             let cond_snip = snippet_with_macro_callsite(cx, cond.span, "[condition]");
             let cond_snip = if matches!(cond.kind, ExprKind::Unary(_, _) | ExprKind::Binary(_, _, _)) {
-                format!("({})", cond_snip)
+                format!("({cond_snip})")
             } else {
                 cond_snip.into_owned()
             };
@@ -92,7 +92,7 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
             let mut method_body = if then_block.stmts.is_empty() {
                 arg_snip.into_owned()
             } else {
-                format!("{{ /* snippet */ {} }}", arg_snip)
+                format!("{{ /* snippet */ {arg_snip} }}")
             };
             let method_name = if switch_to_eager_eval(cx, expr) && meets_msrv(self.msrv, msrvs::BOOL_THEN_SOME) {
                 "then_some"
@@ -102,14 +102,13 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
             };
 
             let help = format!(
-                "consider using `bool::{}` like: `{}.{}({})`",
-                method_name, cond_snip, method_name, method_body,
+                "consider using `bool::{method_name}` like: `{cond_snip}.{method_name}({method_body})`",
             );
             span_lint_and_help(
                 cx,
                 IF_THEN_SOME_ELSE_NONE,
                 expr.span,
-                &format!("this could be simplified with `bool::{}`", method_name),
+                &format!("this could be simplified with `bool::{method_name}`"),
                 None,
                 &help,
             );

clippy_lints/src/implicit_hasher.rs

@@ -89,8 +89,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitHasher {
                     (
                         generics_suggestion_span,
                         format!(
-                            "<{}{}S: ::std::hash::BuildHasher{}>",
-                            generics_snip,
+                            "<{generics_snip}{}S: ::std::hash::BuildHasher{}>",
                             if generics_snip.is_empty() { "" } else { ", " },
                             if vis.suggestions.is_empty() {
                                 ""
@@ -263,8 +262,8 @@ impl<'tcx> ImplicitHasherType<'tcx> {
 
     fn type_arguments(&self) -> String {
         match *self {
-            ImplicitHasherType::HashMap(.., ref k, ref v) => format!("{}, {}", k, v),
-            ImplicitHasherType::HashSet(.., ref t) => format!("{}", t),
+            ImplicitHasherType::HashMap(.., ref k, ref v) => format!("{k}, {v}"),
+            ImplicitHasherType::HashSet(.., ref t) => format!("{t}"),
         }
     }
 

clippy_lints/src/implicit_return.rs

@@ -53,7 +53,7 @@ fn lint_return(cx: &LateContext<'_>, emission_place: HirId, span: Span) {
         span,
         "missing `return` statement",
         |diag| {
-            diag.span_suggestion(span, "add `return` as shown", format!("return {}", snip), app);
+            diag.span_suggestion(span, "add `return` as shown", format!("return {snip}"), app);
         },
     );
 }
@@ -71,7 +71,7 @@ fn lint_break(cx: &LateContext<'_>, emission_place: HirId, break_span: Span, exp
             diag.span_suggestion(
                 break_span,
                 "change `break` to `return` as shown",
-                format!("return {}", snip),
+                format!("return {snip}"),
                 app,
             );
         },

clippy_lints/src/implicit_saturating_sub.rs

@@ -170,7 +170,7 @@ fn print_lint_and_sugg(cx: &LateContext<'_>, var_name: &str, expr: &Expr<'_>) {
         expr.span,
         "implicitly performing saturating subtraction",
         "try",
-        format!("{} = {}.saturating_sub({});", var_name, var_name, '1'),
+        format!("{var_name} = {var_name}.saturating_sub({});", '1'),
         Applicability::MachineApplicable,
     );
 }

clippy_lints/src/inconsistent_struct_constructor.rs

@@ -90,7 +90,7 @@ impl<'tcx> LateLintPass<'tcx> for InconsistentStructConstructor {
                 let mut fields_snippet = String::new();
                 let (last_ident, idents) = ordered_fields.split_last().unwrap();
                 for ident in idents {
-                    let _ = write!(fields_snippet, "{}, ", ident);
+                    let _ = write!(fields_snippet, "{ident}, ");
                 }
                 fields_snippet.push_str(&last_ident.to_string());
 
@@ -100,10 +100,8 @@ impl<'tcx> LateLintPass<'tcx> for InconsistentStructConstructor {
                         String::new()
                     };
 
-                let sugg = format!("{} {{ {}{} }}",
+                let sugg = format!("{} {{ {fields_snippet}{base_snippet} }}",
                     snippet(cx, qpath.span(), ".."),
-                    fields_snippet,
-                    base_snippet,
                     );
 
                 span_lint_and_sugg(

clippy_lints/src/index_refutable_slice.rs

@@ -139,14 +139,14 @@ fn lint_slice(cx: &LateContext<'_>, slice: &SliceLintInformation) {
         .map(|(index, _)| *index)
         .collect::<FxHashSet<_>>();
 
-    let value_name = |index| format!("{}_{}", slice.ident.name, index);
+    let value_name = |index| format!("{}_{index}", slice.ident.name);
 
     if let Some(max_index) = used_indices.iter().max() {
         let opt_ref = if slice.needs_ref { "ref " } else { "" };
         let pat_sugg_idents = (0..=*max_index)
             .map(|index| {
                 if used_indices.contains(&index) {
-                    format!("{}{}", opt_ref, value_name(index))
+                    format!("{opt_ref}{}", value_name(index))
                 } else {
                     "_".to_string()
                 }

clippy_lints/src/inherent_to_string.rs

@@ -131,23 +131,19 @@ fn show_lint(cx: &LateContext<'_>, item: &ImplItem<'_>) {
             INHERENT_TO_STRING_SHADOW_DISPLAY,
             item.span,
             &format!(
-                "type `{}` implements inherent method `to_string(&self) -> String` which shadows the implementation of `Display`",
-                self_type
+                "type `{self_type}` implements inherent method `to_string(&self) -> String` which shadows the implementation of `Display`"
             ),
             None,
-            &format!("remove the inherent method from type `{}`", self_type),
+            &format!("remove the inherent method from type `{self_type}`"),
         );
     } else {
         span_lint_and_help(
             cx,
             INHERENT_TO_STRING,
             item.span,
-            &format!(
-                "implementation of inherent method `to_string(&self) -> String` for type `{}`",
-                self_type
-            ),
+            &format!("implementation of inherent method `to_string(&self) -> String` for type `{self_type}`"),
             None,
-            &format!("implement trait `Display` for type `{}` instead", self_type),
+            &format!("implement trait `Display` for type `{self_type}` instead"),
         );
     }
 }

clippy_lints/src/inline_fn_without_body.rs

@@ -51,7 +51,7 @@ fn check_attrs(cx: &LateContext<'_>, name: Symbol, attrs: &[Attribute]) {
             cx,
             INLINE_FN_WITHOUT_BODY,
             attr.span,
-            &format!("use of `#[inline]` on trait method `{}` which has no body", name),
+            &format!("use of `#[inline]` on trait method `{name}` which has no body"),
             |diag| {
                 diag.suggest_remove_item(cx, attr.span, "remove", Applicability::MachineApplicable);
             },

clippy_lints/src/int_plus_one.rs

@@ -138,8 +138,8 @@ impl IntPlusOne {
         if let Some(snippet) = snippet_opt(cx, node.span) {
             if let Some(other_side_snippet) = snippet_opt(cx, other_side.span) {
                 let rec = match side {
-                    Side::Lhs => Some(format!("{} {} {}", snippet, binop_string, other_side_snippet)),
-                    Side::Rhs => Some(format!("{} {} {}", other_side_snippet, binop_string, snippet)),
+                    Side::Lhs => Some(format!("{snippet} {binop_string} {other_side_snippet}")),
+                    Side::Rhs => Some(format!("{other_side_snippet} {binop_string} {snippet}")),
                 };
                 return rec;
             }

clippy_lints/src/iter_not_returning_iterator.rs

@@ -80,10 +80,7 @@ fn check_sig(cx: &LateContext<'_>, name: &str, sig: &FnSig<'_>, fn_id: LocalDefI
                 cx,
                 ITER_NOT_RETURNING_ITERATOR,
                 sig.span,
-                &format!(
-                    "this method is named `{}` but its return type does not implement `Iterator`",
-                    name
-                ),
+                &format!("this method is named `{name}` but its return type does not implement `Iterator`"),
             );
         }
     }

clippy_lints/src/len_zero.rs

@@ -278,15 +278,13 @@ impl<'tcx> LenOutput<'tcx> {
             _ => "",
         };
         match self {
-            Self::Integral => format!("expected signature: `({}self) -> bool`", self_ref),
-            Self::Option(_) => format!(
-                "expected signature: `({}self) -> bool` or `({}self) -> Option<bool>",
-                self_ref, self_ref
-            ),
-            Self::Result(..) => format!(
-                "expected signature: `({}self) -> bool` or `({}self) -> Result<bool>",
-                self_ref, self_ref
-            ),
+            Self::Integral => format!("expected signature: `({self_ref}self) -> bool`"),
+            Self::Option(_) => {
+                format!("expected signature: `({self_ref}self) -> bool` or `({self_ref}self) -> Option<bool>")
+            },
+            Self::Result(..) => {
+                format!("expected signature: `({self_ref}self) -> bool` or `({self_ref}self) -> Result<bool>")
+            },
         }
     }
 }
@@ -326,8 +324,7 @@ fn check_for_is_empty<'tcx>(
     let (msg, is_empty_span, self_kind) = match is_empty {
         None => (
             format!(
-                "{} `{}` has a public `len` method, but no `is_empty` method",
-                item_kind,
+                "{item_kind} `{}` has a public `len` method, but no `is_empty` method",
                 item_name.as_str(),
             ),
             None,
@@ -335,8 +332,7 @@ fn check_for_is_empty<'tcx>(
         ),
         Some(is_empty) if !cx.access_levels.is_exported(is_empty.def_id.expect_local()) => (
             format!(
-                "{} `{}` has a public `len` method, but a private `is_empty` method",
-                item_kind,
+                "{item_kind} `{}` has a public `len` method, but a private `is_empty` method",
                 item_name.as_str(),
             ),
             Some(cx.tcx.def_span(is_empty.def_id)),
@@ -348,8 +344,7 @@ fn check_for_is_empty<'tcx>(
         {
             (
                 format!(
-                    "{} `{}` has a public `len` method, but the `is_empty` method has an unexpected signature",
-                    item_kind,
+                    "{item_kind} `{}` has a public `len` method, but the `is_empty` method has an unexpected signature",
                     item_name.as_str(),
                 ),
                 Some(cx.tcx.def_span(is_empty.def_id)),
@@ -419,10 +414,9 @@ fn check_len(
                 LEN_ZERO,
                 span,
                 &format!("length comparison to {}", if compare_to == 0 { "zero" } else { "one" }),
-                &format!("using `{}is_empty` is clearer and more explicit", op),
+                &format!("using `{op}is_empty` is clearer and more explicit"),
                 format!(
-                    "{}{}.is_empty()",
-                    op,
+                    "{op}{}.is_empty()",
                     snippet_with_applicability(cx, receiver.span, "_", &mut applicability)
                 ),
                 applicability,
@@ -439,10 +433,9 @@ fn check_empty_expr(cx: &LateContext<'_>, span: Span, lit1: &Expr<'_>, lit2: &Ex
             COMPARISON_TO_EMPTY,
             span,
             "comparison to empty slice",
-            &format!("using `{}is_empty` is clearer and more explicit", op),
+            &format!("using `{op}is_empty` is clearer and more explicit"),
             format!(
-                "{}{}.is_empty()",
-                op,
+                "{op}{}.is_empty()",
                 snippet_with_applicability(cx, lit1.span, "_", &mut applicability)
             ),
             applicability,

clippy_lints/src/let_if_seq.rs

@@ -106,8 +106,7 @@ impl<'tcx> LateLintPass<'tcx> for LetIfSeq {
                     // use mutably after the `if`
 
                     let sug = format!(
-                        "let {mut}{name} = if {cond} {{{then} {value} }} else {{{else} {default} }};",
-                        mut=mutability,
+                        "let {mutability}{name} = if {cond} {{{then} {value} }} else {{{else} {default} }};",
                         name=ident.name,
                         cond=snippet(cx, cond.span, "_"),
                         then=if then.stmts.len() > 1 { " ..;" } else { "" },

clippy_lints/src/lib.rs

@@ -417,8 +417,7 @@ pub fn register_pre_expansion_lints(store: &mut rustc_lint::LintStore, sess: &Se
     let msrv = conf.msrv.as_ref().and_then(|s| {
         parse_msrv(s, None, None).or_else(|| {
             sess.err(&format!(
-                "error reading Clippy's configuration file. `{}` is not a valid Rust version",
-                s
+                "error reading Clippy's configuration file. `{s}` is not a valid Rust version"
             ));
             None
         })
@@ -434,8 +433,7 @@ fn read_msrv(conf: &Conf, sess: &Session) -> Option<RustcVersion> {
     let clippy_msrv = conf.msrv.as_ref().and_then(|s| {
         parse_msrv(s, None, None).or_else(|| {
             sess.err(&format!(
-                "error reading Clippy's configuration file. `{}` is not a valid Rust version",
-                s
+                "error reading Clippy's configuration file. `{s}` is not a valid Rust version"
             ));
             None
         })
@@ -446,8 +444,7 @@ fn read_msrv(conf: &Conf, sess: &Session) -> Option<RustcVersion> {
             // if both files have an msrv, let's compare them and emit a warning if they differ
             if clippy_msrv != cargo_msrv {
                 sess.warn(&format!(
-                    "the MSRV in `clippy.toml` and `Cargo.toml` differ; using `{}` from `clippy.toml`",
-                    clippy_msrv
+                    "the MSRV in `clippy.toml` and `Cargo.toml` differ; using `{clippy_msrv}` from `clippy.toml`"
                 ));
             }
 
@@ -466,7 +463,7 @@ pub fn read_conf(sess: &Session) -> Conf {
         Ok(Some(path)) => path,
         Ok(None) => return Conf::default(),
         Err(error) => {
-            sess.struct_err(&format!("error finding Clippy's configuration file: {}", error))
+            sess.struct_err(&format!("error finding Clippy's configuration file: {error}"))
                 .emit();
             return Conf::default();
         },

clippy_lints/src/literal_representation.rs

@@ -478,7 +478,7 @@ impl DecimalLiteralRepresentation {
             if num_lit.radix == Radix::Decimal;
             if val >= u128::from(self.threshold);
             then {
-                let hex = format!("{:#X}", val);
+                let hex = format!("{val:#X}");
                 let num_lit = NumericLiteral::new(&hex, num_lit.suffix, false);
                 let _ = Self::do_lint(num_lit.integer).map_err(|warning_type| {
                     warning_type.display(num_lit.format(), cx, lit.span);

clippy_lints/src/loops/explicit_counter_loop.rs

@@ -44,11 +44,10 @@ pub(super) fn check<'tcx>(
                                 cx,
                                 EXPLICIT_COUNTER_LOOP,
                                 span,
-                                &format!("the variable `{}` is used as a loop counter", name),
+                                &format!("the variable `{name}` is used as a loop counter"),
                                 "consider using",
                                 format!(
-                                    "for ({}, {}) in {}.enumerate()",
-                                    name,
+                                    "for ({name}, {}) in {}.enumerate()",
                                     snippet_with_applicability(cx, pat.span, "item", &mut applicability),
                                     make_iterator_snippet(cx, arg, &mut applicability),
                                 ),
@@ -65,24 +64,21 @@ pub(super) fn check<'tcx>(
                         cx,
                         EXPLICIT_COUNTER_LOOP,
                         span,
-                        &format!("the variable `{}` is used as a loop counter", name),
+                        &format!("the variable `{name}` is used as a loop counter"),
                         |diag| {
                             diag.span_suggestion(
                                 span,
                                 "consider using",
                                 format!(
-                                    "for ({}, {}) in (0_{}..).zip({})",
-                                    name,
+                                    "for ({name}, {}) in (0_{int_name}..).zip({})",
                                     snippet_with_applicability(cx, pat.span, "item", &mut applicability),
-                                    int_name,
                                     make_iterator_snippet(cx, arg, &mut applicability),
                                 ),
                                 applicability,
                             );
 
                             diag.note(&format!(
-                                "`{}` is of type `{}`, making it ineligible for `Iterator::enumerate`",
-                                name, int_name
+                                "`{name}` is of type `{int_name}`, making it ineligible for `Iterator::enumerate`"
                             ));
                         },
                     );

clippy_lints/src/loops/explicit_iter_loop.rs

@@ -41,7 +41,7 @@ pub(super) fn check(cx: &LateContext<'_>, self_arg: &Expr<'_>, arg: &Expr<'_>, m
         "it is more concise to loop over references to containers instead of using explicit \
          iteration methods",
         "to write this more concisely, try",
-        format!("&{}{}", muta, object),
+        format!("&{muta}{object}"),
         applicability,
     );
 }

clippy_lints/src/loops/for_kv_map.rs

@@ -38,7 +38,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, arg: &'tcx
                     cx,
                     FOR_KV_MAP,
                     arg_span,
-                    &format!("you seem to want to iterate on a map's {}s", kind),
+                    &format!("you seem to want to iterate on a map's {kind}s"),
                     |diag| {
                         let map = sugg::Sugg::hir(cx, arg, "map");
                         multispan_sugg(
@@ -46,7 +46,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, arg: &'tcx
                             "use the corresponding method",
                             vec![
                                 (pat_span, snippet(cx, new_pat_span, kind).into_owned()),
-                                (arg_span, format!("{}.{}s{}()", map.maybe_par(), kind, mutbl)),
+                                (arg_span, format!("{}.{kind}s{mutbl}()", map.maybe_par())),
                             ],
                         );
                     },

clippy_lints/src/loops/manual_flatten.rs

@@ -38,7 +38,7 @@ pub(super) fn check<'tcx>(
         then {
             let if_let_type = if some_ctor { "Some" } else { "Ok" };
             // Prepare the error message
-            let msg = format!("unnecessary `if let` since only the `{}` variant of the iterator element is used", if_let_type);
+            let msg = format!("unnecessary `if let` since only the `{if_let_type}` variant of the iterator element is used");
 
             // Prepare the help message
             let mut applicability = Applicability::MaybeIncorrect;

clippy_lints/src/loops/manual_memcpy.rs

@@ -177,13 +177,7 @@ fn build_manual_memcpy_suggestion<'tcx>(
     let dst = if dst_offset == sugg::EMPTY && dst_limit == sugg::EMPTY {
         dst_base_str
     } else {
-        format!(
-            "{}[{}..{}]",
-            dst_base_str,
-            dst_offset.maybe_par(),
-            dst_limit.maybe_par()
-        )
-        .into()
+        format!("{dst_base_str}[{}..{}]", dst_offset.maybe_par(), dst_limit.maybe_par()).into()
     };
 
     let method_str = if is_copy(cx, elem_ty) {
@@ -193,10 +187,7 @@ fn build_manual_memcpy_suggestion<'tcx>(
     };
 
     format!(
-        "{}.{}(&{}[{}..{}]);",
-        dst,
-        method_str,
-        src_base_str,
+        "{dst}.{method_str}(&{src_base_str}[{}..{}]);",
         src_offset.maybe_par(),
         src_limit.maybe_par()
     )

clippy_lints/src/loops/needless_collect.rs

@@ -45,7 +45,7 @@ fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCont
                         let (arg, pred) = contains_arg
                             .strip_prefix('&')
                             .map_or(("&x", &*contains_arg), |s| ("x", s));
-                        format!("any(|{}| x == {})", arg, pred)
+                        format!("any(|{arg}| x == {pred})")
                     }
                     _ => return,
                 }
@@ -141,9 +141,9 @@ impl IterFunction {
             IterFunctionKind::Contains(span) => {
                 let s = snippet(cx, *span, "..");
                 if let Some(stripped) = s.strip_prefix('&') {
-                    format!(".any(|x| x == {})", stripped)
+                    format!(".any(|x| x == {stripped})")
                 } else {
-                    format!(".any(|x| x == *{})", s)
+                    format!(".any(|x| x == *{s})")
                 }
             },
         }

clippy_lints/src/loops/needless_range_loop.rs

@@ -145,7 +145,7 @@ pub(super) fn check<'tcx>(
                         cx,
                         NEEDLESS_RANGE_LOOP,
                         arg.span,
-                        &format!("the loop variable `{}` is used to index `{}`", ident.name, indexed),
+                        &format!("the loop variable `{}` is used to index `{indexed}`", ident.name),
                         |diag| {
                             multispan_sugg(
                                 diag,
@@ -154,7 +154,7 @@ pub(super) fn check<'tcx>(
                                     (pat.span, format!("({}, <item>)", ident.name)),
                                     (
                                         arg.span,
-                                        format!("{}.{}().enumerate(){}{}", indexed, method, method_1, method_2),
+                                        format!("{indexed}.{method}().enumerate(){method_1}{method_2}"),
                                     ),
                                 ],
                             );
@@ -162,16 +162,16 @@ pub(super) fn check<'tcx>(
                     );
                 } else {
                     let repl = if starts_at_zero && take_is_empty {
-                        format!("&{}{}", ref_mut, indexed)
+                        format!("&{ref_mut}{indexed}")
                     } else {
-                        format!("{}.{}(){}{}", indexed, method, method_1, method_2)
+                        format!("{indexed}.{method}(){method_1}{method_2}")
                     };
 
                     span_lint_and_then(
                         cx,
                         NEEDLESS_RANGE_LOOP,
                         arg.span,
-                        &format!("the loop variable `{}` is only used to index `{}`", ident.name, indexed),
+                        &format!("the loop variable `{}` is only used to index `{indexed}`", ident.name),
                         |diag| {
                             multispan_sugg(
                                 diag,

clippy_lints/src/loops/never_loop.rs

@@ -222,9 +222,5 @@ fn for_to_if_let_sugg(cx: &LateContext<'_>, iterator: &Expr<'_>, pat: &Pat<'_>)
     let pat_snippet = snippet(cx, pat.span, "_");
     let iter_snippet = make_iterator_snippet(cx, iterator, &mut Applicability::Unspecified);
 
-    format!(
-        "if let Some({pat}) = {iter}.next()",
-        pat = pat_snippet,
-        iter = iter_snippet
-    )
+    format!("if let Some({pat_snippet}) = {iter_snippet}.next()")
 }

clippy_lints/src/loops/same_item_push.rs

@@ -30,10 +30,7 @@ pub(super) fn check<'tcx>(
             vec.span,
             "it looks like the same item is being pushed into this Vec",
             None,
-            &format!(
-                "try using vec![{};SIZE] or {}.resize(NEW_SIZE, {})",
-                item_str, vec_str, item_str
-            ),
+            &format!("try using vec![{item_str};SIZE] or {vec_str}.resize(NEW_SIZE, {item_str})"),
         );
     }
 

clippy_lints/src/loops/utils.rs

@@ -344,9 +344,8 @@ pub(super) fn make_iterator_snippet(cx: &LateContext<'_>, arg: &Expr<'_>, applic
                     _ => arg,
                 };
                 format!(
-                    "{}.{}()",
+                    "{}.{method_name}()",
                     sugg::Sugg::hir_with_applicability(cx, caller, "_", applic_ref).maybe_par(),
-                    method_name,
                 )
             },
             _ => format!(

clippy_lints/src/loops/while_let_on_iterator.rs

@@ -67,7 +67,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         expr.span.with_hi(scrutinee_expr.span.hi()),
         "this loop could be written as a `for` loop",
         "try",
-        format!("for {} in {}{}", loop_var, iterator, by_ref),
+        format!("for {loop_var} in {iterator}{by_ref}"),
         applicability,
     );
 }

clippy_lints/src/macro_use.rs

@@ -190,9 +190,9 @@ impl<'tcx> LateLintPass<'tcx> for MacroUseImports {
         let mut suggestions = vec![];
         for ((root, span, hir_id), path) in used {
             if path.len() == 1 {
-                suggestions.push((span, format!("{}::{}", root, path[0]), hir_id));
+                suggestions.push((span, format!("{root}::{}", path[0]), hir_id));
             } else {
-                suggestions.push((span, format!("{}::{{{}}}", root, path.join(", ")), hir_id));
+                suggestions.push((span, format!("{root}::{{{}}}", path.join(", ")), hir_id));
             }
         }
 
@@ -200,7 +200,7 @@ impl<'tcx> LateLintPass<'tcx> for MacroUseImports {
         // such as `std::prelude::v1::foo` or some other macro that expands to an import.
         if self.mac_refs.is_empty() {
             for (span, import, hir_id) in suggestions {
-                let help = format!("use {};", import);
+                let help = format!("use {import};");
                 span_lint_hir_and_then(
                     cx,
                     MACRO_USE_IMPORTS,

clippy_lints/src/manual_async_fn.rs

@@ -74,11 +74,11 @@ impl<'tcx> LateLintPass<'tcx> for ManualAsyncFn {
                             if let Some(ret_pos) = position_before_rarrow(&header_snip);
                             if let Some((ret_sugg, ret_snip)) = suggested_ret(cx, output);
                             then {
-                                let help = format!("make the function `async` and {}", ret_sugg);
+                                let help = format!("make the function `async` and {ret_sugg}");
                                 diag.span_suggestion(
                                     header_span,
                                     &help,
-                                    format!("async {}{}", &header_snip[..ret_pos], ret_snip),
+                                    format!("async {}{ret_snip}", &header_snip[..ret_pos]),
                                     Applicability::MachineApplicable
                                 );
 
@@ -196,7 +196,7 @@ fn suggested_ret(cx: &LateContext<'_>, output: &Ty<'_>) -> Option<(&'static str,
         },
         _ => {
             let sugg = "return the output of the future directly";
-            snippet_opt(cx, output.span).map(|snip| (sugg, format!(" -> {}", snip)))
+            snippet_opt(cx, output.span).map(|snip| (sugg, format!(" -> {snip}")))
         },
     }
 }

clippy_lints/src/manual_non_exhaustive.rs

@@ -133,7 +133,7 @@ impl EarlyLintPass for ManualNonExhaustiveStruct {
                             diag.span_suggestion(
                                 header_span,
                                 "add the attribute",
-                                format!("#[non_exhaustive] {}", snippet),
+                                format!("#[non_exhaustive] {snippet}"),
                                 Applicability::Unspecified,
                             );
                         }
@@ -207,7 +207,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {
                             diag.span_suggestion(
                                 header_span,
                                 "add the attribute",
-                                format!("#[non_exhaustive] {}", snippet),
+                                format!("#[non_exhaustive] {snippet}"),
                                 Applicability::Unspecified,
                             );
                     }

clippy_lints/src/manual_retain.rs

@@ -153,7 +153,7 @@ fn suggest(cx: &LateContext<'_>, parent_expr: &hir::Expr<'_>, left_expr: &hir::E
         && let [filter_params] = filter_body.params
         && let Some(sugg) = match filter_params.pat.kind {
             hir::PatKind::Binding(_, _, filter_param_ident, None) => {
-                Some(format!("{}.retain(|{}| {})", snippet(cx, left_expr.span, ".."), filter_param_ident, snippet(cx, filter_body.value.span, "..")))
+                Some(format!("{}.retain(|{filter_param_ident}| {})", snippet(cx, left_expr.span, ".."), snippet(cx, filter_body.value.span, "..")))
             },
             hir::PatKind::Tuple([key_pat, value_pat], _) => {
                 make_sugg(cx, key_pat, value_pat, left_expr, filter_body)
@@ -161,7 +161,7 @@ fn suggest(cx: &LateContext<'_>, parent_expr: &hir::Expr<'_>, left_expr: &hir::E
             hir::PatKind::Ref(pat, _) => {
                 match pat.kind {
                     hir::PatKind::Binding(_, _, filter_param_ident, None) => {
-                        Some(format!("{}.retain(|{}| {})", snippet(cx, left_expr.span, ".."), filter_param_ident, snippet(cx, filter_body.value.span, "..")))
+                        Some(format!("{}.retain(|{filter_param_ident}| {})", snippet(cx, left_expr.span, ".."), snippet(cx, filter_body.value.span, "..")))
                     },
                     _ => None
                 }
@@ -190,23 +190,19 @@ fn make_sugg(
     match (&key_pat.kind, &value_pat.kind) {
         (hir::PatKind::Binding(_, _, key_param_ident, None), hir::PatKind::Binding(_, _, value_param_ident, None)) => {
             Some(format!(
-                "{}.retain(|{}, &mut {}| {})",
+                "{}.retain(|{key_param_ident}, &mut {value_param_ident}| {})",
                 snippet(cx, left_expr.span, ".."),
-                key_param_ident,
-                value_param_ident,
                 snippet(cx, filter_body.value.span, "..")
             ))
         },
         (hir::PatKind::Binding(_, _, key_param_ident, None), hir::PatKind::Wild) => Some(format!(
-            "{}.retain(|{}, _| {})",
+            "{}.retain(|{key_param_ident}, _| {})",
             snippet(cx, left_expr.span, ".."),
-            key_param_ident,
             snippet(cx, filter_body.value.span, "..")
         )),
         (hir::PatKind::Wild, hir::PatKind::Binding(_, _, value_param_ident, None)) => Some(format!(
-            "{}.retain(|_, &mut {}| {})",
+            "{}.retain(|_, &mut {value_param_ident}| {})",
             snippet(cx, left_expr.span, ".."),
-            value_param_ident,
             snippet(cx, filter_body.value.span, "..")
         )),
         _ => None,

clippy_lints/src/manual_strip.rs

@@ -108,15 +108,14 @@ impl<'tcx> LateLintPass<'tcx> for ManualStrip {
                     };
 
                     let test_span = expr.span.until(then.span);
-                    span_lint_and_then(cx, MANUAL_STRIP, strippings[0], &format!("stripping a {} manually", kind_word), |diag| {
-                        diag.span_note(test_span, &format!("the {} was tested here", kind_word));
+                    span_lint_and_then(cx, MANUAL_STRIP, strippings[0], &format!("stripping a {kind_word} manually"), |diag| {
+                        diag.span_note(test_span, &format!("the {kind_word} was tested here"));
                         multispan_sugg(
                             diag,
-                            &format!("try using the `strip_{}` method", kind_word),
+                            &format!("try using the `strip_{kind_word}` method"),
                             vec![(test_span,
-                                  format!("if let Some(<stripped>) = {}.strip_{}({}) ",
+                                  format!("if let Some(<stripped>) = {}.strip_{kind_word}({}) ",
                                           snippet(cx, target_arg.span, ".."),
-                                          kind_word,
                                           snippet(cx, pattern.span, "..")))]
                             .into_iter().chain(strippings.into_iter().map(|span| (span, "<stripped>".into()))),
                         );

clippy_lints/src/map_unit_fn.rs

@@ -194,10 +194,7 @@ fn let_binding_name(cx: &LateContext<'_>, var_arg: &hir::Expr<'_>) -> String {
 
 #[must_use]
 fn suggestion_msg(function_type: &str, map_type: &str) -> String {
-    format!(
-        "called `map(f)` on an `{0}` value where `f` is a {1} that returns the unit type `()`",
-        map_type, function_type
-    )
+    format!("called `map(f)` on an `{map_type}` value where `f` is a {function_type} that returns the unit type `()`")
 }
 
 fn lint_map_unit_fn(

clippy_lints/src/match_result_ok.rs

@@ -70,9 +70,7 @@ impl<'tcx> LateLintPass<'tcx> for MatchResultOk {
                 let some_expr_string = snippet_with_applicability(cx, y[0].span, "", &mut applicability);
                 let trimmed_ok = snippet_with_applicability(cx, let_expr.span.until(ok_path.ident.span), "", &mut applicability);
                 let sugg = format!(
-                    "{} let Ok({}) = {}",
-                    ifwhile,
-                    some_expr_string,
+                    "{ifwhile} let Ok({some_expr_string}) = {}",
                     trimmed_ok.trim().trim_end_matches('.'),
                 );
                 span_lint_and_sugg(
@@ -80,7 +78,7 @@ impl<'tcx> LateLintPass<'tcx> for MatchResultOk {
                     MATCH_RESULT_OK,
                     expr.span.with_hi(let_expr.span.hi()),
                     "matching on `Some` with `ok()` is redundant",
-                    &format!("consider matching on `Ok({})` and removing the call to `ok` instead", some_expr_string),
+                    &format!("consider matching on `Ok({some_expr_string})` and removing the call to `ok` instead"),
                     sugg,
                     applicability,
                 );

clippy_lints/src/matches/manual_map.rs

@@ -144,7 +144,7 @@ fn check<'tcx>(
     let scrutinee = peel_hir_expr_refs(scrutinee).0;
     let (scrutinee_str, _) = snippet_with_context(cx, scrutinee.span, expr_ctxt, "..", &mut app);
     let scrutinee_str = if scrutinee.span.ctxt() == expr.span.ctxt() && scrutinee.precedence().order() < PREC_POSTFIX {
-        format!("({})", scrutinee_str)
+        format!("({scrutinee_str})")
     } else {
         scrutinee_str.into()
     };
@@ -172,9 +172,9 @@ fn check<'tcx>(
                 };
                 let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
                 if some_expr.needs_unsafe_block {
-                    format!("|{}{}| unsafe {{ {} }}", annotation, some_binding, expr_snip)
+                    format!("|{annotation}{some_binding}| unsafe {{ {expr_snip} }}")
                 } else {
-                    format!("|{}{}| {}", annotation, some_binding, expr_snip)
+                    format!("|{annotation}{some_binding}| {expr_snip}")
                 }
             }
         }
@@ -183,9 +183,9 @@ fn check<'tcx>(
         let pat_snip = snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0;
         let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
         if some_expr.needs_unsafe_block {
-            format!("|{}| unsafe {{ {} }}", pat_snip, expr_snip)
+            format!("|{pat_snip}| unsafe {{ {expr_snip} }}")
         } else {
-            format!("|{}| {}", pat_snip, expr_snip)
+            format!("|{pat_snip}| {expr_snip}")
         }
     } else {
         // Refutable bindings and mixed reference annotations can't be handled by `map`.
@@ -199,9 +199,9 @@ fn check<'tcx>(
         "manual implementation of `Option::map`",
         "try this",
         if else_pat.is_none() && is_else_clause(cx.tcx, expr) {
-            format!("{{ {}{}.map({}) }}", scrutinee_str, as_ref_str, body_str)
+            format!("{{ {scrutinee_str}{as_ref_str}.map({body_str}) }}")
         } else {
-            format!("{}{}.map({})", scrutinee_str, as_ref_str, body_str)
+            format!("{scrutinee_str}{as_ref_str}.map({body_str})")
         },
         app,
     );

clippy_lints/src/matches/manual_unwrap_or.rs

@@ -42,12 +42,10 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, scrutinee:
             span_lint_and_sugg(
                 cx,
                 MANUAL_UNWRAP_OR, expr.span,
-                &format!("this pattern reimplements `{}::unwrap_or`", ty_name),
+                &format!("this pattern reimplements `{ty_name}::unwrap_or`"),
                 "replace with",
                 format!(
-                    "{}.unwrap_or({})",
-                    suggestion,
-                    reindented_or_body,
+                    "{suggestion}.unwrap_or({reindented_or_body})",
                 ),
                 Applicability::MachineApplicable,
             );

clippy_lints/src/matches/match_as_ref.rs

@@ -45,13 +45,11 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr:
                 cx,
                 MATCH_AS_REF,
                 expr.span,
-                &format!("use `{}()` instead", suggestion),
+                &format!("use `{suggestion}()` instead"),
                 "try this",
                 format!(
-                    "{}.{}(){}",
+                    "{}.{suggestion}(){cast}",
                     snippet_with_applicability(cx, ex.span, "_", &mut applicability),
-                    suggestion,
-                    cast,
                 ),
                 applicability,
             );

clippy_lints/src/matches/match_like_matches.rs

@@ -112,7 +112,7 @@ where
                     .join(" | ")
             };
             let pat_and_guard = if let Some(Guard::If(g)) = first_guard {
-                format!("{} if {}", pat, snippet_with_applicability(cx, g.span, "..", &mut applicability))
+                format!("{pat} if {}", snippet_with_applicability(cx, g.span, "..", &mut applicability))
             } else {
                 pat
             };
@@ -131,10 +131,9 @@ where
                 &format!("{} expression looks like `matches!` macro", if is_if_let { "if let .. else" } else { "match" }),
                 "try this",
                 format!(
-                    "{}matches!({}, {})",
+                    "{}matches!({}, {pat_and_guard})",
                     if b0 { "" } else { "!" },
                     snippet_with_applicability(cx, ex_new.span, "..", &mut applicability),
-                    pat_and_guard,
                 ),
                 applicability,
             );

clippy_lints/src/matches/match_same_arms.rs

@@ -135,7 +135,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
                     diag.span_suggestion(
                         keep_arm.pat.span,
                         "try merging the arm patterns",
-                        format!("{} | {}", keep_pat_snip, move_pat_snip),
+                        format!("{keep_pat_snip} | {move_pat_snip}"),
                         Applicability::MaybeIncorrect,
                     )
                     .help("or try changing either arm body")

clippy_lints/src/matches/match_single_binding.rs

@@ -75,12 +75,11 @@ pub(crate) fn check<'a>(cx: &LateContext<'a>, ex: &Expr<'a>, arms: &[Arm<'_>], e
                 Some(AssignmentExpr::Local { span, pat_span }) => (
                     span,
                     format!(
-                        "let {} = {};\n{}let {} = {};",
+                        "let {} = {};\n{}let {} = {snippet_body};",
                         snippet_with_applicability(cx, bind_names, "..", &mut applicability),
                         snippet_with_applicability(cx, matched_vars, "..", &mut applicability),
                         " ".repeat(indent_of(cx, expr.span).unwrap_or(0)),
-                        snippet_with_applicability(cx, pat_span, "..", &mut applicability),
-                        snippet_body
+                        snippet_with_applicability(cx, pat_span, "..", &mut applicability)
                     ),
                 ),
                 None => {
@@ -110,10 +109,8 @@ pub(crate) fn check<'a>(cx: &LateContext<'a>, ex: &Expr<'a>, arms: &[Arm<'_>], e
             if ex.can_have_side_effects() {
                 let indent = " ".repeat(indent_of(cx, expr.span).unwrap_or(0));
                 let sugg = format!(
-                    "{};\n{}{}",
-                    snippet_with_applicability(cx, ex.span, "..", &mut applicability),
-                    indent,
-                    snippet_body
+                    "{};\n{indent}{snippet_body}",
+                    snippet_with_applicability(cx, ex.span, "..", &mut applicability)
                 );
 
                 span_lint_and_sugg(
@@ -178,10 +175,10 @@ fn sugg_with_curlies<'a>(
     let (mut cbrace_start, mut cbrace_end) = (String::new(), String::new());
     if let Some(parent_expr) = get_parent_expr(cx, match_expr) {
         if let ExprKind::Closure { .. } = parent_expr.kind {
-            cbrace_end = format!("\n{}}}", indent);
+            cbrace_end = format!("\n{indent}}}");
             // Fix body indent due to the closure
             indent = " ".repeat(indent_of(cx, bind_names).unwrap_or(0));
-            cbrace_start = format!("{{\n{}", indent);
+            cbrace_start = format!("{{\n{indent}");
         }
     }
 
@@ -190,10 +187,10 @@ fn sugg_with_curlies<'a>(
     let parent_node_id = cx.tcx.hir().get_parent_node(match_expr.hir_id);
     if let Node::Arm(arm) = &cx.tcx.hir().get(parent_node_id) {
         if let ExprKind::Match(..) = arm.body.kind {
-            cbrace_end = format!("\n{}}}", indent);
+            cbrace_end = format!("\n{indent}}}");
             // Fix body indent due to the match
             indent = " ".repeat(indent_of(cx, bind_names).unwrap_or(0));
-            cbrace_start = format!("{{\n{}", indent);
+            cbrace_start = format!("{{\n{indent}");
         }
     }
 
@@ -204,13 +201,8 @@ fn sugg_with_curlies<'a>(
     });
 
     format!(
-        "{}let {} = {};\n{}{}{}{}",
-        cbrace_start,
+        "{cbrace_start}let {} = {};\n{indent}{assignment_str}{snippet_body}{cbrace_end}",
         snippet_with_applicability(cx, bind_names, "..", applicability),
-        snippet_with_applicability(cx, matched_vars, "..", applicability),
-        indent,
-        assignment_str,
-        snippet_body,
-        cbrace_end
+        snippet_with_applicability(cx, matched_vars, "..", applicability)
     )
 }

clippy_lints/src/matches/match_str_case_mismatch.rs

@@ -118,8 +118,8 @@ fn lint(cx: &LateContext<'_>, case_method: &CaseMethod, bad_case_span: Span, bad
         MATCH_STR_CASE_MISMATCH,
         bad_case_span,
         "this `match` arm has a differing case than its expression",
-        &format!("consider changing the case of this arm to respect `{}`", method_str),
-        format!("\"{}\"", suggestion),
+        &format!("consider changing the case of this arm to respect `{method_str}`"),
+        format!("\"{suggestion}\""),
         Applicability::MachineApplicable,
     );
 }

clippy_lints/src/matches/match_wild_err_arm.rs

@@ -38,7 +38,7 @@ pub(crate) fn check<'tcx>(cx: &LateContext<'tcx>, ex: &Expr<'tcx>, arms: &[Arm<'
                             span_lint_and_note(cx,
                                 MATCH_WILD_ERR_ARM,
                                 arm.pat.span,
-                                &format!("`Err({})` matches all errors", ident_bind_name),
+                                &format!("`Err({ident_bind_name})` matches all errors"),
                                 None,
                                 "match each error separately or use the error output, or use `.expect(msg)` if the error case is unreachable",
                             );

clippy_lints/src/matches/redundant_pattern_match.rs

@@ -138,7 +138,7 @@ fn find_sugg_for_if_let<'tcx>(
         cx,
         REDUNDANT_PATTERN_MATCHING,
         let_pat.span,
-        &format!("redundant pattern matching, consider using `{}`", good_method),
+        &format!("redundant pattern matching, consider using `{good_method}`"),
         |diag| {
             // if/while let ... = ... { ... }
             // ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -162,7 +162,7 @@ fn find_sugg_for_if_let<'tcx>(
                 .maybe_par()
                 .to_string();
 
-            diag.span_suggestion(span, "try this", format!("{} {}.{}", keyword, sugg, good_method), app);
+            diag.span_suggestion(span, "try this", format!("{keyword} {sugg}.{good_method}"), app);
 
             if needs_drop {
                 diag.note("this will change drop order of the result, as well as all temporaries");
@@ -252,12 +252,12 @@ pub(super) fn check_match<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, op
                 cx,
                 REDUNDANT_PATTERN_MATCHING,
                 expr.span,
-                &format!("redundant pattern matching, consider using `{}`", good_method),
+                &format!("redundant pattern matching, consider using `{good_method}`"),
                 |diag| {
                     diag.span_suggestion(
                         span,
                         "try this",
-                        format!("{}.{}", snippet(cx, result_expr.span, "_"), good_method),
+                        format!("{}.{good_method}", snippet(cx, result_expr.span, "_")),
                         Applicability::MaybeIncorrect, // snippet
                     );
                 },

clippy_lints/src/matches/significant_drop_in_scrutinee.rs

@@ -50,13 +50,13 @@ fn set_diagnostic<'tcx>(diag: &mut Diagnostic, cx: &LateContext<'tcx>, expr: &'t
     let trailing_indent = " ".repeat(indent_of(cx, found.found_span).unwrap_or(0));
 
     let replacement = if found.lint_suggestion == LintSuggestion::MoveAndDerefToCopy {
-        format!("let value = *{};\n{}", original, trailing_indent)
+        format!("let value = *{original};\n{trailing_indent}")
     } else if found.is_unit_return_val {
         // If the return value of the expression to be moved is unit, then we don't need to
         // capture the result in a temporary -- we can just replace it completely with `()`.
-        format!("{};\n{}", original, trailing_indent)
+        format!("{original};\n{trailing_indent}")
     } else {
-        format!("let value = {};\n{}", original, trailing_indent)
+        format!("let value = {original};\n{trailing_indent}")
     };
 
     let suggestion_message = if found.lint_suggestion == LintSuggestion::MoveOnly {

clippy_lints/src/matches/single_match.rs

@@ -99,23 +99,21 @@ fn report_single_pattern(
 
             let msg = "you seem to be trying to use `match` for an equality check. Consider using `if`";
             let sugg = format!(
-                "if {} == {}{} {}{}",
+                "if {} == {}{} {}{els_str}",
                 snippet(cx, ex.span, ".."),
                 // PartialEq for different reference counts may not exist.
                 "&".repeat(ref_count_diff),
                 snippet(cx, arms[0].pat.span, ".."),
                 expr_block(cx, arms[0].body, None, "..", Some(expr.span)),
-                els_str,
             );
             (msg, sugg)
         } else {
             let msg = "you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`";
             let sugg = format!(
-                "if let {} = {} {}{}",
+                "if let {} = {} {}{els_str}",
                 snippet(cx, arms[0].pat.span, ".."),
                 snippet(cx, ex.span, ".."),
                 expr_block(cx, arms[0].body, None, "..", Some(expr.span)),
-                els_str,
             );
             (msg, sugg)
         }

clippy_lints/src/matches/try_err.rs

@@ -61,9 +61,9 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, scrutine
                 "return "
             };
             let suggestion = if err_ty == expr_err_ty {
-                format!("{}{}{}{}", ret_prefix, prefix, origin_snippet, suffix)
+                format!("{ret_prefix}{prefix}{origin_snippet}{suffix}")
             } else {
-                format!("{}{}{}.into(){}", ret_prefix, prefix, origin_snippet, suffix)
+                format!("{ret_prefix}{prefix}{origin_snippet}.into(){suffix}")
             };
 
             span_lint_and_sugg(

clippy_lints/src/methods/bind_instead_of_map.rs

@@ -85,7 +85,7 @@ pub(crate) trait BindInsteadOfMap {
 
                 let closure_args_snip = snippet(cx, closure_args_span, "..");
                 let option_snip = snippet(cx, recv.span, "..");
-                let note = format!("{}.{}({} {})", option_snip, Self::GOOD_METHOD_NAME, closure_args_snip, some_inner_snip);
+                let note = format!("{option_snip}.{}({closure_args_snip} {some_inner_snip})", Self::GOOD_METHOD_NAME);
                 span_lint_and_sugg(
                     cx,
                     BIND_INSTEAD_OF_MAP,

clippy_lints/src/methods/bytes_nth.rs

@@ -22,7 +22,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, recv: &'tcx E
         cx,
         BYTES_NTH,
         expr.span,
-        &format!("called `.bytes().nth()` on a `{}`", caller_type),
+        &format!("called `.bytes().nth()` on a `{caller_type}`"),
         "try",
         format!(
             "{}.as_bytes().get({})",

clippy_lints/src/methods/chars_cmp.rs

@@ -33,12 +33,11 @@ pub(super) fn check(
                 cx,
                 lint,
                 info.expr.span,
-                &format!("you should use the `{}` method", suggest),
+                &format!("you should use the `{suggest}` method"),
                 "like this",
-                format!("{}{}.{}({})",
+                format!("{}{}.{suggest}({})",
                         if info.eq { "" } else { "!" },
                         snippet_with_applicability(cx, args[0].0.span, "..", &mut applicability),
-                        suggest,
                         snippet_with_applicability(cx, arg_char.span, "..", &mut applicability)),
                 applicability,
             );

clippy_lints/src/methods/chars_cmp_with_unwrap.rs

@@ -26,12 +26,11 @@ pub(super) fn check<'tcx>(
                 cx,
                 lint,
                 info.expr.span,
-                &format!("you should use the `{}` method", suggest),
+                &format!("you should use the `{suggest}` method"),
                 "like this",
-                format!("{}{}.{}('{}')",
+                format!("{}{}.{suggest}('{}')",
                         if info.eq { "" } else { "!" },
                         snippet_with_applicability(cx, args[0].0.span, "..", &mut applicability),
-                        suggest,
                         c.escape_default()),
                 applicability,
             );

clippy_lints/src/methods/clone_on_copy.rs

@@ -49,8 +49,7 @@ pub(super) fn check(
                 expr.span,
                 &format!(
                     "using `clone` on a double-reference; \
-                    this will copy the reference of type `{}` instead of cloning the inner type",
-                    ty
+                    this will copy the reference of type `{ty}` instead of cloning the inner type"
                 ),
                 |diag| {
                     if let Some(snip) = sugg::Sugg::hir_opt(cx, arg) {
@@ -62,11 +61,11 @@ pub(super) fn check(
                         }
                         let refs = "&".repeat(n + 1);
                         let derefs = "*".repeat(n);
-                        let explicit = format!("<{}{}>::clone({})", refs, ty, snip);
+                        let explicit = format!("<{refs}{ty}>::clone({snip})");
                         diag.span_suggestion(
                             expr.span,
                             "try dereferencing it",
-                            format!("{}({}{}).clone()", refs, derefs, snip.deref()),
+                            format!("{refs}({derefs}{}).clone()", snip.deref()),
                             Applicability::MaybeIncorrect,
                         );
                         diag.span_suggestion(
@@ -121,16 +120,16 @@ pub(super) fn check(
         let (help, sugg) = if deref_count == 0 {
             ("try removing the `clone` call", snip.into())
         } else if parent_is_suffix_expr {
-            ("try dereferencing it", format!("({}{})", "*".repeat(deref_count), snip))
+            ("try dereferencing it", format!("({}{snip})", "*".repeat(deref_count)))
         } else {
-            ("try dereferencing it", format!("{}{}", "*".repeat(deref_count), snip))
+            ("try dereferencing it", format!("{}{snip}", "*".repeat(deref_count)))
         };
 
         span_lint_and_sugg(
             cx,
             CLONE_ON_COPY,
             expr.span,
-            &format!("using `clone` on type `{}` which implements the `Copy` trait", ty),
+            &format!("using `clone` on type `{ty}` which implements the `Copy` trait"),
             help,
             sugg,
             app,

clippy_lints/src/methods/clone_on_ref_ptr.rs

@@ -41,7 +41,7 @@ pub(super) fn check(
             expr.span,
             "using `.clone()` on a ref-counted pointer",
             "try this",
-            format!("{}::<{}>::clone(&{})", caller_type, subst.type_at(0), snippet),
+            format!("{caller_type}::<{}>::clone(&{snippet})", subst.type_at(0)),
             Applicability::Unspecified, // Sometimes unnecessary ::<_> after Rc/Arc/Weak
         );
     }