Rollup merge of #80546 - matthiaskrgr:rustdoclippy, r=LingMan

clippy fixes for librustdoc

fixes clippy warnings of type:
match_like_matches_macro
or_fun_call
op_ref
needless_return
let_and_return
single_char_add_str
useless_format
unnecessary_sort_by
match_ref_pats
redundant_field_names

4 files changed, 23 insertions, 26 deletions

diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index 9b2fb8582f5..6eeb7ad82c0 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -245,7 +245,7 @@ impl<'a> fmt::Display for WhereClause<'a> {
             }
 
             match pred {
-                &clean::WherePredicate::BoundPredicate { ref ty, ref bounds } => {
+                clean::WherePredicate::BoundPredicate { ty, bounds } => {
                     let bounds = bounds;
                     if f.alternate() {
                         clause.push_str(&format!(
@@ -261,7 +261,7 @@ impl<'a> fmt::Display for WhereClause<'a> {
                         ));
                     }
                 }
-                &clean::WherePredicate::RegionPredicate { ref lifetime, ref bounds } => {
+                clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
                     clause.push_str(&format!(
                         "{}: {}",
                         lifetime.print(),
@@ -272,7 +272,7 @@ impl<'a> fmt::Display for WhereClause<'a> {
                             .join(" + ")
                     ));
                 }
-                &clean::WherePredicate::EqPredicate { ref lhs, ref rhs } => {
+                clean::WherePredicate::EqPredicate { lhs, rhs } => {
                     if f.alternate() {
                         clause.push_str(&format!("{:#} == {:#}", lhs.print(), rhs.print()));
                     } else {
@@ -376,8 +376,8 @@ impl clean::GenericBound {
 impl clean::GenericArgs {
     fn print(&self) -> impl fmt::Display + '_ {
         display_fn(move |f| {
-            match *self {
-                clean::GenericArgs::AngleBracketed { ref args, ref bindings } => {
+            match self {
+                clean::GenericArgs::AngleBracketed { args, bindings } => {
                     if !args.is_empty() || !bindings.is_empty() {
                         if f.alternate() {
                             f.write_str("<")?;
@@ -414,7 +414,7 @@ impl clean::GenericArgs {
                         }
                     }
                 }
-                clean::GenericArgs::Parenthesized { ref inputs, ref output } => {
+                clean::GenericArgs::Parenthesized { inputs, output } => {
                     f.write_str("(")?;
                     let mut comma = false;
                     for ty in inputs {
@@ -501,7 +501,7 @@ crate fn href(did: DefId) -> Option<(String, ItemType, Vec<String>)> {
     };
     for component in &fqp[..fqp.len() - 1] {
         url.push_str(component);
-        url.push_str("/");
+        url.push('/');
     }
     match shortty {
         ItemType::Module => {
@@ -510,7 +510,7 @@ crate fn href(did: DefId) -> Option<(String, ItemType, Vec<String>)> {
         }
         _ => {
             url.push_str(shortty.as_str());
-            url.push_str(".");
+            url.push('.');
             url.push_str(fqp.last().unwrap());
             url.push_str(".html");
         }
@@ -1021,7 +1021,7 @@ impl Function<'_> {
                 } else {
                     if i > 0 {
                         args.push_str(" <br>");
-                        args_plain.push_str(" ");
+                        args_plain.push(' ');
                     }
                     if !input.name.is_empty() {
                         args.push_str(&format!("{}: ", input.name));
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 20cf48915c3..e519c6ee983 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -489,15 +489,10 @@ impl<'a, I: Iterator<Item = Event<'a>>> SummaryLine<'a, I> {
 }
 
 fn check_if_allowed_tag(t: &Tag<'_>) -> bool {
-    match *t {
-        Tag::Paragraph
-        | Tag::Item
-        | Tag::Emphasis
-        | Tag::Strong
-        | Tag::Link(..)
-        | Tag::BlockQuote => true,
-        _ => false,
-    }
+    matches!(
+        t,
+        Tag::Paragraph | Tag::Item | Tag::Emphasis | Tag::Strong | Tag::Link(..) | Tag::BlockQuote
+    )
 }
 
 impl<'a, I: Iterator<Item = Event<'a>>> Iterator for SummaryLine<'a, I> {
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index c19262b72cf..2f5ee4f238d 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -979,7 +979,7 @@ themePicker.onblur = handleThemeButtonsBlur;
                 .iter()
                 .map(|s| format!("\"{}\"", s.to_str().expect("invalid osstring conversion")))
                 .collect::<Vec<_>>();
-            files.sort_unstable_by(|a, b| a.cmp(b));
+            files.sort_unstable();
             let subs = subs.iter().map(|s| s.to_json_string()).collect::<Vec<_>>().join(",");
             let dirs =
                 if subs.is_empty() { String::new() } else { format!(",\"dirs\":[{}]", subs) };
@@ -1428,7 +1428,7 @@ impl Setting {
                     .map(|opt| format!(
                         "<option value=\"{}\" {}>{}</option>",
                         opt.0,
-                        if &opt.0 == default_value { "selected" } else { "" },
+                        if opt.0 == default_value { "selected" } else { "" },
                         opt.1,
                     ))
                     .collect::<String>(),
@@ -1595,7 +1595,7 @@ impl Context<'_> {
             if let Some(&(ref names, ty)) = cache.paths.get(&it.def_id) {
                 for name in &names[..names.len() - 1] {
                     url.push_str(name);
-                    url.push_str("/");
+                    url.push('/');
                 }
                 url.push_str(&item_path(ty, names.last().unwrap()));
                 layout::redirect(&url)
@@ -2308,7 +2308,7 @@ fn short_item_info(
             let since = &since.as_str();
             if !stability::deprecation_in_effect(is_since_rustc_version, Some(since)) {
                 if *since == "TBD" {
-                    format!("Deprecating in a future Rust version")
+                    String::from("Deprecating in a future Rust version")
                 } else {
                     format!("Deprecating in {}", Escape(since))
                 }
@@ -4323,9 +4323,11 @@ fn sidebar_assoc_items(it: &clean::Item) -> String {
                         .any(|i| i.inner_impl().trait_.def_id() == c.deref_mut_trait_did);
                     let inner_impl = target
                         .def_id()
-                        .or(target
-                            .primitive_type()
-                            .and_then(|prim| c.primitive_locations.get(&prim).cloned()))
+                        .or_else(|| {
+                            target
+                                .primitive_type()
+                                .and_then(|prim| c.primitive_locations.get(&prim).cloned())
+                        })
                         .and_then(|did| c.impls.get(&did));
                     if let Some(impls) = inner_impl {
                         out.push_str("<a class=\"sidebar-title\" href=\"#deref-methods\">");
diff --git a/src/librustdoc/html/toc.rs b/src/librustdoc/html/toc.rs
index b39a4e179cd..c55f2459a9c 100644
--- a/src/librustdoc/html/toc.rs
+++ b/src/librustdoc/html/toc.rs
@@ -132,7 +132,7 @@ impl TocBuilder {
                 }
                 Some(entry) => {
                     sec_number = entry.sec_number.clone();
-                    sec_number.push_str(".");
+                    sec_number.push('.');
                     (entry.level, &entry.children)
                 }
             };