Improve code readability by moving fmt args directly into the string

src/librustdoc/clean/auto_trait.rs

@@ -46,7 +46,7 @@ where
         let tcx = self.cx.tcx;
         let trait_ref = ty::Binder::dummy(ty::TraitRef::new(tcx, trait_def_id, [ty]));
         if !self.cx.generated_synthetics.insert((ty, trait_def_id)) {
-            debug!("get_auto_trait_impl_for({:?}): already generated, aborting", trait_ref);
+            debug!("get_auto_trait_impl_for({trait_ref:?}): already generated, aborting");
             return None;
         }
 
@@ -140,7 +140,7 @@ where
         let ty = tcx.type_of(item_def_id).instantiate_identity();
         let f = auto_trait::AutoTraitFinder::new(tcx);
 
-        debug!("get_auto_trait_impls({:?})", ty);
+        debug!("get_auto_trait_impls({ty:?})");
         let auto_traits: Vec<_> = self.cx.auto_traits.to_vec();
         let mut auto_traits: Vec<Item> = auto_traits
             .into_iter()
@@ -163,9 +163,9 @@ where
     fn get_lifetime(region: Region<'_>, names_map: &FxHashMap<Symbol, Lifetime>) -> Lifetime {
         region_name(region)
             .map(|name| {
-                names_map.get(&name).unwrap_or_else(|| {
-                    panic!("Missing lifetime with name {:?} for {:?}", name.as_str(), region)
-                })
+                names_map
+                    .get(&name)
+                    .unwrap_or_else(|| panic!("Missing lifetime with name {name:?} for {region:?}"))
             })
             .unwrap_or(&Lifetime::statik())
             .clone()
@@ -372,7 +372,7 @@ where
 
                     let output = output.as_ref().cloned().map(Box::new);
                     if old_output.is_some() && old_output != output {
-                        panic!("Output mismatch for {:?} {:?} {:?}", ty, old_output, output);
+                        panic!("Output mismatch for {ty:?} {old_output:?} {output:?}");
                     }
 
                     let new_params = GenericArgs::Parenthesized { inputs: old_input, output };
@@ -462,7 +462,7 @@ where
         );
         let mut generic_params = raw_generics.params;
 
-        debug!("param_env_to_generics({:?}): generic_params={:?}", item_def_id, generic_params);
+        debug!("param_env_to_generics({item_def_id:?}): generic_params={generic_params:?}");
 
         let mut has_sized = FxHashSet::default();
         let mut ty_to_bounds: FxHashMap<_, FxHashSet<_>> = Default::default();
@@ -623,7 +623,7 @@ where
                             // loop
                             ty_to_traits.entry(ty.clone()).or_default().insert(trait_.clone());
                         }
-                        _ => panic!("Unexpected LHS {:?} for {:?}", lhs, item_def_id),
+                        _ => panic!("Unexpected LHS {lhs:?} for {item_def_id:?}"),
                     }
                 }
             };
@@ -710,7 +710,7 @@ where
     /// involved (impls rarely have more than a few bounds) means that it
     /// shouldn't matter in practice.
     fn unstable_debug_sort<T: Debug>(&self, vec: &mut [T]) {
-        vec.sort_by_cached_key(|x| format!("{:?}", x))
+        vec.sort_by_cached_key(|x| format!("{x:?}"))
     }
 
     fn is_fn_trait(&self, path: &Path) -> bool {

src/librustdoc/clean/blanket_impl.rs

@@ -17,7 +17,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
         let param_env = cx.tcx.param_env(item_def_id);
         let ty = cx.tcx.type_of(item_def_id);
 
-        trace!("get_blanket_impls({:?})", ty);
+        trace!("get_blanket_impls({ty:?})");
         let mut impls = Vec::new();
         for trait_def_id in cx.tcx.all_traits() {
             if !cx.cache.effective_visibilities.is_reachable(cx.tcx, trait_def_id)
@@ -72,7 +72,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
                     .into_iter()
                     .chain(Some(ty::Binder::dummy(impl_trait_ref).to_predicate(infcx.tcx)));
                 for predicate in predicates {
-                    debug!("testing predicate {:?}", predicate);
+                    debug!("testing predicate {predicate:?}");
                     let obligation = traits::Obligation::new(
                         infcx.tcx,
                         traits::ObligationCause::dummy(),

src/librustdoc/clean/cfg.rs

@@ -434,9 +434,9 @@ impl<'a> fmt::Display for Display<'a> {
                     }
                     if let (true, Cfg::Cfg(_, Some(feat))) = (short_longhand, sub_cfg) {
                         if self.1.is_html() {
-                            write!(fmt, "<code>{}</code>", feat)?;
+                            write!(fmt, "<code>{feat}</code>")?;
                         } else {
-                            write!(fmt, "`{}`", feat)?;
+                            write!(fmt, "`{feat}`")?;
                         }
                     } else {
                         write_with_opt_paren(fmt, !sub_cfg.is_all(), Display(sub_cfg, self.1))?;
@@ -471,9 +471,9 @@ impl<'a> fmt::Display for Display<'a> {
                     }
                     if let (true, Cfg::Cfg(_, Some(feat))) = (short_longhand, sub_cfg) {
                         if self.1.is_html() {
-                            write!(fmt, "<code>{}</code>", feat)?;
+                            write!(fmt, "<code>{feat}</code>")?;
                         } else {
-                            write!(fmt, "`{}`", feat)?;
+                            write!(fmt, "`{feat}`")?;
                         }
                     } else {
                         write_with_opt_paren(fmt, !sub_cfg.is_simple(), Display(sub_cfg, self.1))?;
@@ -551,21 +551,21 @@ impl<'a> fmt::Display for Display<'a> {
                         "sgx" => "SGX",
                         _ => "",
                     },
-                    (sym::target_endian, Some(endian)) => return write!(fmt, "{}-endian", endian),
-                    (sym::target_pointer_width, Some(bits)) => return write!(fmt, "{}-bit", bits),
+                    (sym::target_endian, Some(endian)) => return write!(fmt, "{endian}-endian"),
+                    (sym::target_pointer_width, Some(bits)) => return write!(fmt, "{bits}-bit"),
                     (sym::target_feature, Some(feat)) => match self.1 {
                         Format::LongHtml => {
-                            return write!(fmt, "target feature <code>{}</code>", feat);
+                            return write!(fmt, "target feature <code>{feat}</code>");
                         }
-                        Format::LongPlain => return write!(fmt, "target feature `{}`", feat),
-                        Format::ShortHtml => return write!(fmt, "<code>{}</code>", feat),
+                        Format::LongPlain => return write!(fmt, "target feature `{feat}`"),
+                        Format::ShortHtml => return write!(fmt, "<code>{feat}</code>"),
                     },
                     (sym::feature, Some(feat)) => match self.1 {
                         Format::LongHtml => {
-                            return write!(fmt, "crate feature <code>{}</code>", feat);
+                            return write!(fmt, "crate feature <code>{feat}</code>");
                         }
-                        Format::LongPlain => return write!(fmt, "crate feature `{}`", feat),
-                        Format::ShortHtml => return write!(fmt, "<code>{}</code>", feat),
+                        Format::LongPlain => return write!(fmt, "crate feature `{feat}`"),
+                        Format::ShortHtml => return write!(fmt, "<code>{feat}</code>"),
                     },
                     _ => "",
                 };
@@ -580,12 +580,12 @@ impl<'a> fmt::Display for Display<'a> {
                             Escape(v.as_str())
                         )
                     } else {
-                        write!(fmt, r#"`{}="{}"`"#, name, v)
+                        write!(fmt, r#"`{name}="{v}"`"#)
                     }
                 } else if self.1.is_html() {
                     write!(fmt, "<code>{}</code>", Escape(name.as_str()))
                 } else {
-                    write!(fmt, "`{}`", name)
+                    write!(fmt, "`{name}`")
                 }
             }
         }

src/librustdoc/clean/inline.rs

@@ -50,7 +50,7 @@ pub(crate) fn try_inline(
     }
     let mut ret = Vec::new();
 
-    debug!("attrs={:?}", attrs);
+    debug!("attrs={attrs:?}");
 
     let attrs_without_docs = attrs.map(|(attrs, def_id)| {
         (attrs.into_iter().filter(|a| a.doc_str().is_none()).cloned().collect::<Vec<_>>(), def_id)
@@ -529,7 +529,7 @@ pub(crate) fn build_impl(
     }
 
     let (merged_attrs, cfg) = merge_attrs(cx, load_attrs(cx, did), attrs);
-    trace!("merged_attrs={:?}", merged_attrs);
+    trace!("merged_attrs={merged_attrs:?}");
 
     trace!(
         "build_impl: impl {:?} for {:?}",
@@ -781,7 +781,7 @@ pub(crate) fn record_extern_trait(cx: &mut DocContext<'_>, did: DefId) {
         cx.active_extern_traits.insert(did);
     }
 
-    debug!("record_extern_trait: {:?}", did);
+    debug!("record_extern_trait: {did:?}");
     let trait_ = build_external_trait(cx, did);
 
     cx.external_traits.borrow_mut().insert(did, trait_);

src/librustdoc/clean/mod.rs

@@ -215,7 +215,7 @@ pub(crate) fn clean_trait_ref_with_bindings<'tcx>(
 ) -> Path {
     let kind = cx.tcx.def_kind(trait_ref.def_id()).into();
     if !matches!(kind, ItemType::Trait | ItemType::TraitAlias) {
-        span_bug!(cx.tcx.def_span(trait_ref.def_id()), "`TraitRef` had unexpected kind {:?}", kind);
+        span_bug!(cx.tcx.def_span(trait_ref.def_id()), "`TraitRef` had unexpected kind {kind:?}");
     }
     inline::record_extern_fqn(cx, trait_ref.def_id(), kind);
     let path =
@@ -304,7 +304,7 @@ pub(crate) fn clean_middle_region<'tcx>(region: ty::Region<'tcx>) -> Option<Life
         | ty::ReError(_)
         | ty::RePlaceholder(..)
         | ty::ReErased => {
-            debug!("cannot clean region {:?}", region);
+            debug!("cannot clean region {region:?}");
             None
         }
     }
@@ -1867,11 +1867,11 @@ fn normalize<'tcx>(
         .map(|resolved| infcx.resolve_vars_if_possible(resolved.value));
     match normalized {
         Ok(normalized_value) => {
-            debug!("normalized {:?} to {:?}", ty, normalized_value);
+            debug!("normalized {ty:?} to {normalized_value:?}");
             Some(normalized_value)
         }
         Err(err) => {
-            debug!("failed to normalize {:?}: {:?}", ty, err);
+            debug!("failed to normalize {ty:?}: {err:?}");
             None
         }
     }

src/librustdoc/clean/types.rs

@@ -78,7 +78,7 @@ impl ItemId {
     #[track_caller]
     pub(crate) fn expect_def_id(self) -> DefId {
         self.as_def_id()
-            .unwrap_or_else(|| panic!("ItemId::expect_def_id: `{:?}` isn't a DefId", self))
+            .unwrap_or_else(|| panic!("ItemId::expect_def_id: `{self:?}` isn't a DefId"))
     }
 
     #[inline]
@@ -352,7 +352,7 @@ fn is_field_vis_inherited(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     match tcx.def_kind(parent) {
         DefKind::Struct | DefKind::Union => false,
         DefKind::Variant => true,
-        parent_kind => panic!("unexpected parent kind: {:?}", parent_kind),
+        parent_kind => panic!("unexpected parent kind: {parent_kind:?}"),
     }
 }
 
@@ -436,7 +436,7 @@ impl Item {
         attrs: Box<Attributes>,
         cfg: Option<Arc<Cfg>>,
     ) -> Item {
-        trace!("name={:?}, def_id={:?} cfg={:?}", name, def_id, cfg);
+        trace!("name={name:?}, def_id={def_id:?} cfg={cfg:?}");
 
         Item {
             item_id: def_id.into(),

src/librustdoc/clean/utils.rs

@@ -218,7 +218,7 @@ pub(crate) fn build_deref_target_impls(
 
 pub(crate) fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
     use rustc_hir::*;
-    debug!("trying to get a name from pattern: {:?}", p);
+    debug!("trying to get a name from pattern: {p:?}");
 
     Symbol::intern(&match p.kind {
         PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
@@ -461,7 +461,7 @@ pub(crate) fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
 
 /// Given a type Path, resolve it to a Type using the TyCtxt
 pub(crate) fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
-    debug!("resolve_type({:?})", path);
+    debug!("resolve_type({path:?})");
 
     match path.res {
         Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
@@ -500,7 +500,7 @@ pub(crate) fn get_auto_trait_and_blanket_impls(
 /// [`href()`]: crate::html::format::href
 pub(crate) fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
     use DefKind::*;
-    debug!("register_res({:?})", res);
+    debug!("register_res({res:?})");
 
     let (kind, did) = match res {
         Res::Def(
@@ -523,7 +523,7 @@ pub(crate) fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
             did,
         ) => (kind.into(), did),
 
-        _ => panic!("register_res: unexpected {:?}", res),
+        _ => panic!("register_res: unexpected {res:?}"),
     };
     if did.is_local() {
         return did;
@@ -601,8 +601,12 @@ pub(super) fn render_macro_arms<'a>(
 ) -> String {
     let mut out = String::new();
     for matcher in matchers {
-        writeln!(out, "    {} => {{ ... }}{}", render_macro_matcher(tcx, matcher), arm_delim)
-            .unwrap();
+        writeln!(
+            out,
+            "    {matcher} => {{ ... }}{arm_delim}",
+            matcher = render_macro_matcher(tcx, matcher),
+        )
+        .unwrap();
     }
     out
 }
@@ -618,21 +622,21 @@ pub(super) fn display_macro_source(
     let matchers = def.body.tokens.chunks(4).map(|arm| &arm[0]);
 
     if def.macro_rules {
-        format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(cx.tcx, matchers, ";"))
+        format!("macro_rules! {name} {{\n{arms}}}", arms = render_macro_arms(cx.tcx, matchers, ";"))
     } else {
         if matchers.len() <= 1 {
             format!(
-                "{}macro {}{} {{\n    ...\n}}",
-                visibility_to_src_with_space(Some(vis), cx.tcx, def_id),
-                name,
-                matchers.map(|matcher| render_macro_matcher(cx.tcx, matcher)).collect::<String>(),
+                "{vis}macro {name}{matchers} {{\n    ...\n}}",
+                vis = visibility_to_src_with_space(Some(vis), cx.tcx, def_id),
+                matchers = matchers
+                    .map(|matcher| render_macro_matcher(cx.tcx, matcher))
+                    .collect::<String>(),
             )
         } else {
             format!(
-                "{}macro {} {{\n{}}}",
-                visibility_to_src_with_space(Some(vis), cx.tcx, def_id),
-                name,
-                render_macro_arms(cx.tcx, matchers, ","),
+                "{vis}macro {name} {{\n{arms}}}",
+                vis = visibility_to_src_with_space(Some(vis), cx.tcx, def_id),
+                arms = render_macro_arms(cx.tcx, matchers, ","),
             )
         }
     }