Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

18 files changed, 1063 insertions, 534 deletions

diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index d963d6092..54c0cd2ef 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -347,13 +347,19 @@ pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
             }
         } else {
             let mut br_with_padding = String::with_capacity(6 * indent + 28);
-            br_with_padding.push_str("\n");
+            br_with_padding.push('\n');
 
-            let padding_amount =
-                if ending == Ending::Newline { indent + 4 } else { indent + "fn where ".len() };
+            let where_indent = 3;
+            let padding_amount = if ending == Ending::Newline {
+                indent + 4
+            } else if indent == 0 {
+                4
+            } else {
+                indent + where_indent + "where ".len()
+            };
 
             for _ in 0..padding_amount {
-                br_with_padding.push_str(" ");
+                br_with_padding.push(' ');
             }
             let where_preds = where_preds.to_string().replace('\n', &br_with_padding);
 
@@ -370,7 +376,8 @@ pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
                     let where_preds = where_preds.replacen(&br_with_padding, " ", 1);
 
                     let mut clause = br_with_padding;
-                    clause.truncate(clause.len() - "where ".len());
+                    // +1 is for `\n`.
+                    clause.truncate(indent + 1 + where_indent);
 
                     write!(clause, "<span class=\"where\">where{where_preds}</span>")?;
                     clause
@@ -1257,9 +1264,9 @@ impl clean::Impl {
                 };
                 primitive_link_fragment(f, PrimitiveType::Tuple, &format!("fn ({name}₁, {name}₂, …, {name}ₙ{ellipsis})"), "#trait-implementations-1", cx)?;
                 // Write output.
-                if let clean::FnRetTy::Return(ty) = &bare_fn.decl.output {
+                if !bare_fn.decl.output.is_unit() {
                     write!(f, " -> ")?;
-                    fmt_type(ty, f, use_absolute, cx)?;
+                    fmt_type(&bare_fn.decl.output, f, use_absolute, cx)?;
                 }
             } else if let Some(ty) = self.kind.as_blanket_ty() {
                 fmt_type(ty, f, use_absolute, cx)?;
@@ -1296,22 +1303,6 @@ impl clean::Arguments {
     }
 }
 
-impl clean::FnRetTy {
-    pub(crate) fn print<'a, 'tcx: 'a>(
-        &'a self,
-        cx: &'a Context<'tcx>,
-    ) -> impl fmt::Display + 'a + Captures<'tcx> {
-        display_fn(move |f| match self {
-            clean::Return(clean::Tuple(tys)) if tys.is_empty() => Ok(()),
-            clean::Return(ty) if f.alternate() => {
-                write!(f, " -> {:#}", ty.print(cx))
-            }
-            clean::Return(ty) => write!(f, " -&gt; {}", ty.print(cx)),
-            clean::DefaultReturn => Ok(()),
-        })
-    }
-}
-
 impl clean::BareFunctionDecl {
     fn print_hrtb_with_space<'a, 'tcx: 'a>(
         &'a self,
@@ -1366,7 +1357,7 @@ impl clean::FnDecl {
                     "({args:#}{ellipsis}){arrow:#}",
                     args = self.inputs.print(cx),
                     ellipsis = ellipsis,
-                    arrow = self.output.print(cx)
+                    arrow = self.print_output(cx)
                 )
             } else {
                 write!(
@@ -1374,7 +1365,7 @@ impl clean::FnDecl {
                     "({args}{ellipsis}){arrow}",
                     args = self.inputs.print(cx),
                     ellipsis = ellipsis,
-                    arrow = self.output.print(cx)
+                    arrow = self.print_output(cx)
                 )
             }
         })
@@ -1417,7 +1408,7 @@ impl clean::FnDecl {
         let amp = if f.alternate() { "&" } else { "&amp;" };
 
         write!(f, "(")?;
-        if let Some(n) = line_wrapping_indent {
+        if let Some(n) = line_wrapping_indent && !self.inputs.values.is_empty() {
             write!(f, "\n{}", Indent(n + 4))?;
         }
         for (i, input) in self.inputs.values.iter().enumerate() {
@@ -1464,9 +1455,22 @@ impl clean::FnDecl {
             Some(n) => write!(f, "\n{})", Indent(n))?,
         };
 
-        fmt::Display::fmt(&self.output.print(cx), f)?;
+        fmt::Display::fmt(&self.print_output(cx), f)?;
         Ok(())
     }
+
+    fn print_output<'a, 'tcx: 'a>(
+        &'a self,
+        cx: &'a Context<'tcx>,
+    ) -> impl fmt::Display + 'a + Captures<'tcx> {
+        display_fn(move |f| match &self.output {
+            clean::Tuple(tys) if tys.is_empty() => Ok(()),
+            ty if f.alternate() => {
+                write!(f, " -> {:#}", ty.print(cx))
+            }
+            ty => write!(f, " -&gt; {}", ty.print(cx)),
+        })
+    }
 }
 
 pub(crate) fn visibility_print_with_space<'a, 'tcx: 'a>(
diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 6ab849c92..8c5871d91 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -55,6 +55,7 @@ struct PageLayout<'a> {
     sidebar: String,
     content: String,
     krate_with_trailing_slash: String,
+    rust_channel: &'static str,
     pub(crate) rustdoc_version: &'a str,
 }
 
@@ -82,6 +83,7 @@ pub(crate) fn render<T: Print, S: Print>(
         sidebar,
         content,
         krate_with_trailing_slash,
+        rust_channel: *crate::clean::utils::DOC_CHANNEL,
         rustdoc_version,
     }
     .render()
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 9bb20022c..fd00277e2 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -381,7 +381,6 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for LinkReplacer<'a, I> {
             Some(Event::Code(text)) => {
                 trace!("saw code {}", text);
                 if let Some(link) = self.shortcut_link {
-                    trace!("original text was {}", link.original_text);
                     // NOTE: this only replaces if the code block is the *entire* text.
                     // If only part of the link has code highlighting, the disambiguator will not be removed.
                     // e.g. [fn@`f`]
@@ -390,8 +389,11 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for LinkReplacer<'a, I> {
                     // So we could never be sure we weren't replacing too much:
                     // [fn@my_`f`unc] is treated the same as [my_func()] in that pass.
                     //
-                    // NOTE: &[1..len() - 1] is to strip the backticks
-                    if **text == link.original_text[1..link.original_text.len() - 1] {
+                    // NOTE: .get(1..len() - 1) is to strip the backticks
+                    if let Some(link) = self.links.iter().find(|l| {
+                        l.href == link.href
+                            && Some(&**text) == l.original_text.get(1..l.original_text.len() - 1)
+                    }) {
                         debug!("replacing {} with {}", text, link.new_text);
                         *text = CowStr::Borrowed(&link.new_text);
                     }
@@ -402,9 +404,12 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for LinkReplacer<'a, I> {
             Some(Event::Text(text)) => {
                 trace!("saw text {}", text);
                 if let Some(link) = self.shortcut_link {
-                    trace!("original text was {}", link.original_text);
                     // NOTE: same limitations as `Event::Code`
-                    if **text == *link.original_text {
+                    if let Some(link) = self
+                        .links
+                        .iter()
+                        .find(|l| l.href == link.href && **text == *l.original_text)
+                    {
                         debug!("replacing {} with {}", text, link.new_text);
                         *text = CowStr::Borrowed(&link.new_text);
                     }
@@ -781,7 +786,7 @@ impl<'tcx> ExtraInfo<'tcx> {
         ExtraInfo { def_id, sp, tcx }
     }
 
-    fn error_invalid_codeblock_attr(&self, msg: String, help: &str) {
+    fn error_invalid_codeblock_attr(&self, msg: String, help: &'static str) {
         if let Some(def_id) = self.def_id.as_local() {
             self.tcx.struct_span_lint_hir(
                 crate::lint::INVALID_CODEBLOCK_ATTRIBUTES,
@@ -1520,7 +1525,6 @@ fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     map.insert("toggle-all-docs".into(), 1);
     map.insert("all-types".into(), 1);
     map.insert("default-settings".into(), 1);
-    map.insert("rustdoc-vars".into(), 1);
     map.insert("sidebar-vars".into(), 1);
     map.insert("copy-path".into(), 1);
     map.insert("TOC".into(), 1);
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index 56af257fd..4c4762636 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -73,6 +73,8 @@ pub(crate) struct Context<'tcx> {
     pub(crate) include_sources: bool,
     /// Collection of all types with notable traits referenced in the current module.
     pub(crate) types_with_notable_traits: FxHashSet<clean::Type>,
+    /// Field used during rendering, to know if we're inside an inlined item.
+    pub(crate) is_inside_inlined_module: bool,
 }
 
 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
@@ -171,6 +173,19 @@ impl<'tcx> Context<'tcx> {
     }
 
     fn render_item(&mut self, it: &clean::Item, is_module: bool) -> String {
+        let mut render_redirect_pages = self.render_redirect_pages;
+        // If the item is stripped but inlined, links won't point to the item so no need to generate
+        // a file for it.
+        if it.is_stripped() &&
+            let Some(def_id) = it.def_id() &&
+            def_id.is_local()
+        {
+            if self.is_inside_inlined_module || self.shared.cache.inlined_items.contains(&def_id) {
+                // For now we're forced to generate a redirect page for stripped items until
+                // `record_extern_fqn` correctly points to external items.
+                render_redirect_pages = true;
+            }
+        }
         let mut title = String::new();
         if !is_module {
             title.push_str(it.name.unwrap().as_str());
@@ -205,7 +220,7 @@ impl<'tcx> Context<'tcx> {
             tyname.as_str()
         };
 
-        if !self.render_redirect_pages {
+        if !render_redirect_pages {
             let clone_shared = Rc::clone(&self.shared);
             let page = layout::Page {
                 css_class: tyname_s,
@@ -545,6 +560,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             shared: Rc::new(scx),
             include_sources,
             types_with_notable_traits: FxHashSet::default(),
+            is_inside_inlined_module: false,
         };
 
         if emit_crate {
@@ -574,6 +590,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             shared: Rc::clone(&self.shared),
             include_sources: self.include_sources,
             types_with_notable_traits: FxHashSet::default(),
+            is_inside_inlined_module: self.is_inside_inlined_module,
         }
     }
 
@@ -768,12 +785,22 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
 
         info!("Recursing into {}", self.dst.display());
 
-        let buf = self.render_item(item, true);
-        // buf will be empty if the module is stripped and there is no redirect for it
-        if !buf.is_empty() {
-            self.shared.ensure_dir(&self.dst)?;
-            let joint_dst = self.dst.join("index.html");
-            self.shared.fs.write(joint_dst, buf)?;
+        if !item.is_stripped() {
+            let buf = self.render_item(item, true);
+            // buf will be empty if the module is stripped and there is no redirect for it
+            if !buf.is_empty() {
+                self.shared.ensure_dir(&self.dst)?;
+                let joint_dst = self.dst.join("index.html");
+                self.shared.fs.write(joint_dst, buf)?;
+            }
+        }
+        if !self.is_inside_inlined_module {
+            if let Some(def_id) = item.def_id() && self.cache().inlined_items.contains(&def_id) {
+                self.is_inside_inlined_module = true;
+            }
+        } else if item.is_doc_hidden() {
+            // We're not inside an inlined module anymore since this one cannot be re-exported.
+            self.is_inside_inlined_module = false;
         }
 
         // Render sidebar-items.js used throughout this module.
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 9e3b5d10a..f923f9054 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -421,11 +421,10 @@ fn document<'a, 'cx: 'a>(
     display_fn(move |f| {
         document_item_info(cx, item, parent).render_into(f).unwrap();
         if parent.is_none() {
-            write!(f, "{}", document_full_collapsible(item, cx, heading_offset))?;
+            write!(f, "{}", document_full_collapsible(item, cx, heading_offset))
         } else {
-            write!(f, "{}", document_full(item, cx, heading_offset))?;
+            write!(f, "{}", document_full(item, cx, heading_offset))
         }
-        Ok(())
     })
 }
 
@@ -787,10 +786,12 @@ fn assoc_type(
     indent: usize,
     cx: &Context<'_>,
 ) {
+    let tcx = cx.tcx();
     write!(
         w,
-        "{indent}type <a{href} class=\"associatedtype\">{name}</a>{generics}",
+        "{indent}{vis}type <a{href} class=\"associatedtype\">{name}</a>{generics}",
         indent = " ".repeat(indent),
+        vis = visibility_print_with_space(it.visibility(tcx), it.item_id, cx),
         href = assoc_href_attr(it, link, cx),
         name = it.name.as_ref().unwrap(),
         generics = generics.print(cx),
@@ -798,10 +799,11 @@ fn assoc_type(
     if !bounds.is_empty() {
         write!(w, ": {}", print_generic_bounds(bounds, cx))
     }
-    write!(w, "{}", print_where_clause(generics, cx, indent, Ending::NoNewline));
+    // Render the default before the where-clause which aligns with the new recommended style. See #89122.
     if let Some(default) = default {
         write!(w, " = {}", default.print(cx))
     }
+    write!(w, "{}", print_where_clause(generics, cx, indent, Ending::NoNewline));
 }
 
 fn assoc_method(
@@ -844,7 +846,7 @@ fn assoc_method(
         + name.as_str().len()
         + generics_len;
 
-    let notable_traits = d.output.as_return().and_then(|output| notable_traits_button(output, cx));
+    let notable_traits = notable_traits_button(&d.output, cx);
 
     let (indent, indent_str, end_newline) = if parent == ItemType::Trait {
         header_len += 4;
@@ -858,8 +860,8 @@ fn assoc_method(
     w.reserve(header_len + "<a href=\"\" class=\"fn\">{".len() + "</a>".len());
     write!(
         w,
-        "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn <a{href} class=\"fn\">{name}</a>\
-         {generics}{decl}{notable_traits}{where_clause}",
+        "{indent}{vis}{constness}{asyncness}{unsafety}{defaultness}{abi}fn \
+         <a{href} class=\"fn\">{name}</a>{generics}{decl}{notable_traits}{where_clause}",
         indent = indent_str,
         vis = vis,
         constness = constness,
@@ -1038,9 +1040,9 @@ fn render_attributes_in_pre<'a, 'b: 'a>(
 
 // When an attribute is rendered inside a <code> tag, it is formatted using
 // a div to produce a newline after it.
-fn render_attributes_in_code(w: &mut Buffer, it: &clean::Item, tcx: TyCtxt<'_>) {
-    for a in it.attributes(tcx, false) {
-        write!(w, "<div class=\"code-attribute\">{}</div>", a);
+fn render_attributes_in_code(w: &mut impl fmt::Write, it: &clean::Item, tcx: TyCtxt<'_>) {
+    for attr in it.attributes(tcx, false) {
+        write!(w, "<div class=\"code-attribute\">{attr}</div>").unwrap();
     }
 }
 
@@ -1282,6 +1284,11 @@ fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) ->
 pub(crate) fn notable_traits_button(ty: &clean::Type, cx: &mut Context<'_>) -> Option<String> {
     let mut has_notable_trait = false;
 
+    if ty.is_unit() {
+        // Very common fast path.
+        return None;
+    }
+
     let did = ty.def_id(cx.cache())?;
 
     // Box has pass-through impls for Read, Write, Iterator, and Future when the
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index 62027a3fa..383e3c170 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -9,7 +9,6 @@ use rustc_middle::middle::stability;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{kw, sym, Symbol};
-use std::borrow::Borrow;
 use std::cell::{RefCell, RefMut};
 use std::cmp::Ordering;
 use std::fmt;
@@ -40,6 +39,110 @@ use crate::html::{highlight, static_files};
 use askama::Template;
 use itertools::Itertools;
 
+/// Generates an Askama template struct for rendering items with common methods.
+///
+/// Usage:
+/// ```ignore (illustrative)
+/// item_template!(
+///     #[template(path = "<template.html>", /* additional values */)]
+///     /* additional meta items */
+///     struct MyItem<'a, 'cx> {
+///         cx: RefCell<&'a mut Context<'cx>>,
+///         it: &'a clean::Item,
+///         /* additional fields */
+///     },
+///     methods = [ /* method names (comma separated; refer to macro definition of `item_template_methods!()`) */ ]
+/// )
+/// ```
+///
+/// NOTE: ensure that the generic lifetimes (`'a`, `'cx`) and
+/// required fields (`cx`, `it`) are identical (in terms of order and definition).
+macro_rules! item_template {
+    (
+        $(#[$meta:meta])*
+        struct $name:ident<'a, 'cx> {
+            cx: RefCell<&'a mut Context<'cx>>,
+            it: &'a clean::Item,
+            $($field_name:ident: $field_ty:ty),*,
+        },
+        methods = [$($methods:tt),* $(,)?]
+    ) => {
+        #[derive(Template)]
+        $(#[$meta])*
+        struct $name<'a, 'cx> {
+            cx: RefCell<&'a mut Context<'cx>>,
+            it: &'a clean::Item,
+            $($field_name: $field_ty),*
+        }
+
+        impl<'a, 'cx: 'a> ItemTemplate<'a, 'cx> for $name<'a, 'cx> {
+            fn item_and_mut_cx(&self) -> (&'a clean::Item, RefMut<'_, &'a mut Context<'cx>>) {
+                (&self.it, self.cx.borrow_mut())
+            }
+        }
+
+        impl<'a, 'cx: 'a> $name<'a, 'cx> {
+            item_template_methods!($($methods)*);
+        }
+    };
+}
+
+/// Implement common methods for item template structs generated by `item_template!()`.
+///
+/// NOTE: this macro is intended to be used only by `item_template!()`.
+macro_rules! item_template_methods {
+    () => {};
+    (document $($rest:tt)*) => {
+        fn document<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+            display_fn(move |f| {
+                let (item, mut cx) = self.item_and_mut_cx();
+                let v = document(*cx, item, None, HeadingOffset::H2);
+                write!(f, "{v}")
+            })
+        }
+        item_template_methods!($($rest)*);
+    };
+    (document_type_layout $($rest:tt)*) => {
+        fn document_type_layout<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+            display_fn(move |f| {
+                let (item, cx) = self.item_and_mut_cx();
+                let def_id = item.item_id.expect_def_id();
+                let v = document_type_layout(*cx, def_id);
+                write!(f, "{v}")
+            })
+        }
+        item_template_methods!($($rest)*);
+    };
+    (render_attributes_in_pre $($rest:tt)*) => {
+        fn render_attributes_in_pre<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+            display_fn(move |f| {
+                let (item, cx) = self.item_and_mut_cx();
+                let tcx = cx.tcx();
+                let v = render_attributes_in_pre(item, "", tcx);
+                write!(f, "{v}")
+            })
+        }
+        item_template_methods!($($rest)*);
+    };
+    (render_assoc_items $($rest:tt)*) => {
+        fn render_assoc_items<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+            display_fn(move |f| {
+                let (item, mut cx) = self.item_and_mut_cx();
+                let def_id = item.item_id.expect_def_id();
+                let v = render_assoc_items(*cx, item, def_id, AssocItemRender::All);
+                write!(f, "{v}")
+            })
+        }
+        item_template_methods!($($rest)*);
+    };
+    ($method:ident $($rest:tt)*) => {
+        compile_error!(concat!("unknown method: ", stringify!($method)));
+    };
+    ($token:tt $($rest:tt)*) => {
+        compile_error!(concat!("unexpected token: ", stringify!($token)));
+    };
+}
+
 const ITEM_TABLE_OPEN: &str = "<ul class=\"item-table\">";
 const ITEM_TABLE_CLOSE: &str = "</ul>";
 const ITEM_TABLE_ROW_OPEN: &str = "<li>";
@@ -222,49 +325,6 @@ trait ItemTemplate<'a, 'cx: 'a>: askama::Template + fmt::Display {
     fn item_and_mut_cx(&self) -> (&'a clean::Item, RefMut<'_, &'a mut Context<'cx>>);
 }
 
-fn item_template_document<'a: 'b, 'b, 'cx: 'a>(
-    templ: &'b impl ItemTemplate<'a, 'cx>,
-) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-    display_fn(move |f| {
-        let (item, mut cx) = templ.item_and_mut_cx();
-        let v = document(*cx, item, None, HeadingOffset::H2);
-        write!(f, "{v}")
-    })
-}
-
-fn item_template_document_type_layout<'a: 'b, 'b, 'cx: 'a>(
-    templ: &'b impl ItemTemplate<'a, 'cx>,
-) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-    display_fn(move |f| {
-        let (item, cx) = templ.item_and_mut_cx();
-        let def_id = item.item_id.expect_def_id();
-        let v = document_type_layout(*cx, def_id);
-        write!(f, "{v}")
-    })
-}
-
-fn item_template_render_attributes_in_pre<'a: 'b, 'b, 'cx: 'a>(
-    templ: &'b impl ItemTemplate<'a, 'cx>,
-) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-    display_fn(move |f| {
-        let (item, cx) = templ.item_and_mut_cx();
-        let tcx = cx.tcx();
-        let v = render_attributes_in_pre(item, "", tcx);
-        write!(f, "{v}")
-    })
-}
-
-fn item_template_render_assoc_items<'a: 'b, 'b, 'cx: 'a>(
-    templ: &'b impl ItemTemplate<'a, 'cx>,
-) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-    display_fn(move |f| {
-        let (item, mut cx) = templ.item_and_mut_cx();
-        let def_id = item.item_id.expect_def_id();
-        let v = render_assoc_items(*cx, item, def_id, AssocItemRender::All);
-        write!(f, "{v}")
-    })
-}
-
 fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items: &[clean::Item]) {
     write!(w, "{}", document(cx, item, None, HeadingOffset::H2));
 
@@ -587,8 +647,7 @@ fn item_function(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, f: &cle
         + name.as_str().len()
         + generics_len;
 
-    let notable_traits =
-        f.decl.output.as_return().and_then(|output| notable_traits_button(output, cx));
+    let notable_traits = notable_traits_button(&f.decl.output, cx);
 
     wrap_item(w, |w| {
         w.reserve(header_len);
@@ -1102,7 +1161,12 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
     );
 }
 
-fn item_trait_alias(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::TraitAlias) {
+fn item_trait_alias(
+    w: &mut impl fmt::Write,
+    cx: &mut Context<'_>,
+    it: &clean::Item,
+    t: &clean::TraitAlias,
+) {
     wrap_item(w, |w| {
         write!(
             w,
@@ -1112,19 +1176,25 @@ fn item_trait_alias(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &
             print_where_clause(&t.generics, cx, 0, Ending::Newline),
             bounds(&t.bounds, true, cx),
             attrs = render_attributes_in_pre(it, "", cx.tcx()),
-        );
+        )
+        .unwrap();
     });
 
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
-
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
     // Render any items associated directly to this alias, as otherwise they
     // won't be visible anywhere in the docs. It would be nice to also show
     // associated items from the aliased type (see discussion in #32077), but
     // we need #14072 to make sense of the generics.
     write!(w, "{}", render_assoc_items(cx, it, it.item_id.expect_def_id(), AssocItemRender::All))
+        .unwrap();
 }
 
-fn item_opaque_ty(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::OpaqueTy) {
+fn item_opaque_ty(
+    w: &mut impl fmt::Write,
+    cx: &mut Context<'_>,
+    it: &clean::Item,
+    t: &clean::OpaqueTy,
+) {
     wrap_item(w, |w| {
         write!(
             w,
@@ -1134,16 +1204,18 @@ fn item_opaque_ty(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &cl
             where_clause = print_where_clause(&t.generics, cx, 0, Ending::Newline),
             bounds = bounds(&t.bounds, false, cx),
             attrs = render_attributes_in_pre(it, "", cx.tcx()),
-        );
+        )
+        .unwrap();
     });
 
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
 
     // Render any items associated directly to this alias, as otherwise they
     // won't be visible anywhere in the docs. It would be nice to also show
     // associated items from the aliased type (see discussion in #32077), but
     // we need #14072 to make sense of the generics.
     write!(w, "{}", render_assoc_items(cx, it, it.item_id.expect_def_id(), AssocItemRender::All))
+        .unwrap();
 }
 
 fn item_typedef(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::Typedef) {
@@ -1176,19 +1248,15 @@ fn item_typedef(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clea
 }
 
 fn item_union(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean::Union) {
-    #[derive(Template)]
-    #[template(path = "item_union.html")]
-    struct ItemUnion<'a, 'cx> {
-        cx: RefCell<&'a mut Context<'cx>>,
-        it: &'a clean::Item,
-        s: &'a clean::Union,
-    }
-
-    impl<'a, 'cx: 'a> ItemTemplate<'a, 'cx> for ItemUnion<'a, 'cx> {
-        fn item_and_mut_cx(&self) -> (&'a clean::Item, RefMut<'_, &'a mut Context<'cx>>) {
-            (self.it, self.cx.borrow_mut())
-        }
-    }
+    item_template!(
+        #[template(path = "item_union.html")]
+        struct ItemUnion<'a, 'cx> {
+            cx: RefCell<&'a mut Context<'cx>>,
+            it: &'a clean::Item,
+            s: &'a clean::Union,
+        },
+        methods = [document, document_type_layout, render_attributes_in_pre, render_assoc_items]
+    );
 
     impl<'a, 'cx: 'a> ItemUnion<'a, 'cx> {
         fn render_union<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
@@ -1198,6 +1266,7 @@ fn item_union(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean:
                 write!(f, "{v}")
             })
         }
+
         fn document_field<'b>(
             &'b self,
             field: &'a clean::Item,
@@ -1208,10 +1277,12 @@ fn item_union(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean:
                 write!(f, "{v}")
             })
         }
+
         fn stability_field(&self, field: &clean::Item) -> Option<String> {
             let cx = self.cx.borrow();
             field.stability_class(cx.tcx())
         }
+
         fn print_ty<'b>(
             &'b self,
             ty: &'a clean::Type,
@@ -1420,37 +1491,41 @@ fn item_macro(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
     write!(w, "{}", document(cx, it, None, HeadingOffset::H2))
 }
 
-fn item_proc_macro(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, m: &clean::ProcMacro) {
-    wrap_item(w, |w| {
+fn item_proc_macro(
+    w: &mut impl fmt::Write,
+    cx: &mut Context<'_>,
+    it: &clean::Item,
+    m: &clean::ProcMacro,
+) {
+    wrap_item(w, |buffer| {
         let name = it.name.expect("proc-macros always have names");
         match m.kind {
             MacroKind::Bang => {
-                write!(w, "{}!() {{ /* proc-macro */ }}", name);
+                write!(buffer, "{name}!() {{ /* proc-macro */ }}").unwrap();
             }
             MacroKind::Attr => {
-                write!(w, "#[{}]", name);
+                write!(buffer, "#[{name}]").unwrap();
             }
             MacroKind::Derive => {
-                write!(w, "#[derive({})]", name);
+                write!(buffer, "#[derive({name})]").unwrap();
                 if !m.helpers.is_empty() {
-                    w.push_str("\n{\n");
-                    w.push_str("    // Attributes available to this derive:\n");
+                    buffer.write_str("\n{\n    // Attributes available to this derive:\n").unwrap();
                     for attr in &m.helpers {
-                        writeln!(w, "    #[{}]", attr);
+                        writeln!(buffer, "    #[{attr}]").unwrap();
                     }
-                    w.push_str("}\n");
+                    buffer.write_str("}\n").unwrap();
                 }
             }
         }
     });
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2))
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
 }
 
-fn item_primitive(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item) {
+fn item_primitive(w: &mut impl fmt::Write, cx: &mut Context<'_>, it: &clean::Item) {
     let def_id = it.item_id.expect_def_id();
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
     if it.name.map(|n| n.as_str() != "reference").unwrap_or(false) {
-        write!(w, "{}", render_assoc_items(cx, it, def_id, AssocItemRender::All));
+        write!(w, "{}", render_assoc_items(cx, it, def_id, AssocItemRender::All)).unwrap();
     } else {
         // We handle the "reference" primitive type on its own because we only want to list
         // implementations on generic types.
@@ -1560,8 +1635,7 @@ fn item_struct(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean
 }
 
 fn item_static(w: &mut impl fmt::Write, cx: &mut Context<'_>, it: &clean::Item, s: &clean::Static) {
-    let mut buffer = Buffer::new();
-    wrap_item(&mut buffer, |buffer| {
+    wrap_item(w, |buffer| {
         render_attributes_in_code(buffer, it, cx.tcx());
         write!(
             buffer,
@@ -1570,29 +1644,29 @@ fn item_static(w: &mut impl fmt::Write, cx: &mut Context<'_>, it: &clean::Item,
             mutability = s.mutability.print_with_space(),
             name = it.name.unwrap(),
             typ = s.type_.print(cx)
-        );
+        )
+        .unwrap();
     });
 
-    write!(w, "{}", buffer.into_inner()).unwrap();
-
     write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
 }
 
-fn item_foreign_type(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item) {
-    wrap_item(w, |w| {
-        w.write_str("extern {\n");
-        render_attributes_in_code(w, it, cx.tcx());
+fn item_foreign_type(w: &mut impl fmt::Write, cx: &mut Context<'_>, it: &clean::Item) {
+    wrap_item(w, |buffer| {
+        buffer.write_str("extern {\n").unwrap();
+        render_attributes_in_code(buffer, it, cx.tcx());
         write!(
-            w,
+            buffer,
             "    {}type {};\n}}",
             visibility_print_with_space(it.visibility(cx.tcx()), it.item_id, cx),
             it.name.unwrap(),
-        );
+        )
+        .unwrap();
     });
 
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
-
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
     write!(w, "{}", render_assoc_items(cx, it, it.item_id.expect_def_id(), AssocItemRender::All))
+        .unwrap();
 }
 
 fn item_keyword(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item) {
@@ -1666,13 +1740,14 @@ fn bounds(t_bounds: &[clean::GenericBound], trait_alias: bool, cx: &Context<'_>)
     bounds
 }
 
-fn wrap_item<F>(w: &mut Buffer, f: F)
+fn wrap_item<W, F>(w: &mut W, f: F)
 where
-    F: FnOnce(&mut Buffer),
+    W: fmt::Write,
+    F: FnOnce(&mut W),
 {
-    w.write_str(r#"<pre class="rust item-decl"><code>"#);
+    write!(w, r#"<pre class="rust item-decl"><code>"#).unwrap();
     f(w);
-    w.write_str("</code></pre>");
+    write!(w, "</code></pre>").unwrap();
 }
 
 #[derive(PartialEq, Eq)]
diff --git a/src/librustdoc/html/render/search_index.rs b/src/librustdoc/html/render/search_index.rs
index 846299f02..f34be120d 100644
--- a/src/librustdoc/html/render/search_index.rs
+++ b/src/librustdoc/html/render/search_index.rs
@@ -7,7 +7,7 @@ use rustc_span::symbol::Symbol;
 use serde::ser::{Serialize, SerializeStruct, Serializer};
 
 use crate::clean;
-use crate::clean::types::{FnRetTy, Function, Generics, ItemId, Type, WherePredicate};
+use crate::clean::types::{Function, Generics, ItemId, Type, WherePredicate};
 use crate::formats::cache::{Cache, OrphanImplItem};
 use crate::formats::item_type::ItemType;
 use crate::html::format::join_with_double_colon;
@@ -656,22 +656,9 @@ fn get_fn_inputs_and_outputs<'tcx>(
     }
 
     let mut ret_types = Vec::new();
-    match decl.output {
-        FnRetTy::Return(ref return_type) => {
-            add_generics_and_bounds_as_types(
-                self_,
-                generics,
-                return_type,
-                tcx,
-                0,
-                &mut ret_types,
-                cache,
-            );
-            if ret_types.is_empty() {
-                ret_types.push(get_index_type(return_type, vec![]));
-            }
-        }
-        _ => {}
-    };
+    add_generics_and_bounds_as_types(self_, generics, &decl.output, tcx, 0, &mut ret_types, cache);
+    if ret_types.is_empty() {
+        ret_types.push(get_index_type(&decl.output, vec![]));
+    }
     (all_types, ret_types)
 }
diff --git a/src/librustdoc/html/render/type_layout.rs b/src/librustdoc/html/render/type_layout.rs
index c9b95b1e6..0bc32ea5a 100644
--- a/src/librustdoc/html/render/type_layout.rs
+++ b/src/librustdoc/html/render/type_layout.rs
@@ -17,7 +17,7 @@ use crate::html::render::Context;
 #[template(path = "type_layout.html")]
 struct TypeLayout<'cx> {
     variants: Vec<(Symbol, TypeLayoutSize)>,
-    type_layout_size: Result<TypeLayoutSize, LayoutError<'cx>>,
+    type_layout_size: Result<TypeLayoutSize, &'cx LayoutError<'cx>>,
 }
 
 #[derive(Template)]
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index a7d5f4977..b7f455259 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -8,6 +8,7 @@
 
 :root {
 	--nav-sub-mobile-padding: 8px;
+	--search-typename-width: 6.75rem;
 }
 
 /* See FiraSans-LICENSE.txt for the Fira Sans license. */
@@ -213,7 +214,7 @@ a.anchor,
 h1 a,
 .search-results a,
 .stab,
-.result-name .primitive > i, .result-name .keyword > i {
+.result-name i {
 	color: var(--main-color);
 }
 
@@ -869,14 +870,11 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	gap: 1em;
 }
 
-.search-results > a > div {
-	flex: 1;
-}
-
 .search-results > a > div.desc {
 	white-space: nowrap;
 	text-overflow: ellipsis;
 	overflow: hidden;
+	flex: 2;
 }
 
 .search-results a:hover,
@@ -884,12 +882,28 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	background-color: var(--search-result-link-focus-background-color);
 }
 
+.search-results .result-name {
+	display: flex;
+	align-items: center;
+	justify-content: start;
+	flex: 3;
+}
 .search-results .result-name span.alias {
 	color: var(--search-results-alias-color);
 }
-.search-results .result-name span.grey {
+.search-results .result-name .grey {
 	color: var(--search-results-grey-color);
 }
+.search-results .result-name .typename {
+	color: var(--search-results-grey-color);
+	font-size: 0.875rem;
+	width: var(--search-typename-width);
+}
+.search-results .result-name .path {
+	word-break: break-all;
+	max-width: calc(100% - var(--search-typename-width));
+	display: inline-block;
+}
 
 .popover {
 	position: absolute;
@@ -957,6 +971,8 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	display: flex;
 	padding: 3px;
 	margin-bottom: 5px;
+	align-items: center;
+	vertical-align: text-bottom;
 }
 .item-name .stab {
 	margin-left: 0.3125em;
@@ -968,11 +984,9 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	color: var(--main-color);
 	background-color: var(--stab-background-color);
 	width: fit-content;
-	align-items: center;
 	white-space: pre-wrap;
 	border-radius: 3px;
-	display: inline-flex;
-	vertical-align: text-bottom;
+	display: inline;
 }
 
 .stab.portability > code {
@@ -1179,6 +1193,10 @@ a.test-arrow:hover {
 	position: relative;
 }
 
+.code-header a.tooltip:hover {
+	color: var(--link-color);
+}
+
 /* placeholder thunk so that the mouse can easily travel from "(i)" to popover
 	the resulting "hover tunnel" is a stepped triangle, approximating
 	https://bjk5.com/post/44698559168/breaking-down-amazons-mega-dropdown */
@@ -1191,6 +1209,14 @@ a.tooltip:hover::after {
 	content: "\00a0";
 }
 
+/* This animation is layered onto the mistake-proofing delay for dismissing
+	a hovered tooltip, to ensure it feels responsive even with the delay.
+	*/
+.fade-out {
+	opacity: 0;
+	transition: opacity 0.45s cubic-bezier(0, 0, 0.1, 1.0);
+}
+
 .popover.tooltip .content {
 	margin: 0.25em 0.5em;
 }
@@ -1712,6 +1738,16 @@ in source-script.js
 	.search-results > a > div.desc, .item-table > li > div.desc {
 		padding-left: 2em;
 	}
+	.search-results .result-name {
+		display: block;
+	}
+	.search-results .result-name .typename {
+		width: initial;
+		margin-right: 0;
+	}
+	.search-results .result-name .typename, .search-results .result-name .path {
+		display: inline;
+	}
 
 	.source-sidebar-expanded .source .sidebar {
 		max-width: 100vw;
diff --git a/src/librustdoc/html/static/js/externs.js b/src/librustdoc/html/static/js/externs.js
index 8b931f74e..f697abd07 100644
--- a/src/librustdoc/html/static/js/externs.js
+++ b/src/librustdoc/html/static/js/externs.js
@@ -53,7 +53,7 @@ let ParsedQuery;
  *    parent: (Object|null|undefined),
  *    path: string,
  *    ty: (Number|null|number),
- *    type: (Array<?>|null)
+ *    type: FunctionSearchType?
  * }}
  */
 let Row;
@@ -135,7 +135,7 @@ let RawFunctionType;
 /**
  * @typedef {{
  *     inputs: Array<FunctionType>,
- *     outputs: Array<FunctionType>,
+ *     output: Array<FunctionType>,
  * }}
  */
 let FunctionSearchType;
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index bccf675c1..254b0d8bf 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -4,6 +4,13 @@
 
 "use strict";
 
+// The amount of time that the cursor must remain still over a hover target before
+// revealing a tooltip.
+//
+// https://www.nngroup.com/articles/timing-exposing-content/
+window.RUSTDOC_TOOLTIP_HOVER_MS = 300;
+window.RUSTDOC_TOOLTIP_HOVER_EXIT_MS = 450;
+
 // Given a basename (e.g. "storage") and an extension (e.g. ".js"), return a URL
 // for a resource under the root-path, with the resource-suffix.
 function resourcePath(basename, extension) {
@@ -270,14 +277,18 @@ function preLoadCss(cssUrl) {
             searchState.mouseMovedAfterSearch = false;
             document.title = searchState.title;
         },
-        hideResults: () => {
-            switchDisplayedElement(null);
+        removeQueryParameters: () => {
+            // We change the document title.
             document.title = searchState.titleBeforeSearch;
-            // We also remove the query parameter from the URL.
             if (browserSupportsHistoryApi()) {
                 history.replaceState(null, "", getNakedUrl() + window.location.hash);
             }
         },
+        hideResults: () => {
+            switchDisplayedElement(null);
+            // We also remove the query parameter from the URL.
+            searchState.removeQueryParameters();
+        },
         getQueryStringParams: () => {
             const params = {};
             window.location.search.substring(1).split("&").
@@ -772,6 +783,13 @@ function preLoadCss(cssUrl) {
         });
     });
 
+    /**
+     * Show a tooltip immediately.
+     *
+     * @param {DOMElement} e - The tooltip's anchor point. The DOM is consulted to figure
+     *                         out what the tooltip should contain, and where it should be
+     *                         positioned.
+     */
     function showTooltip(e) {
         const notable_ty = e.getAttribute("data-notable-ty");
         if (!window.NOTABLE_TRAITS && notable_ty) {
@@ -782,8 +800,10 @@ function preLoadCss(cssUrl) {
                 throw new Error("showTooltip() called with notable without any notable traits!");
             }
         }
+        // Make this function idempotent. If the tooltip is already shown, avoid doing extra work
+        // and leave it alone.
         if (window.CURRENT_TOOLTIP_ELEMENT && window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE === e) {
-            // Make this function idempotent.
+            clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
             return;
         }
         window.hideAllModals(false);
@@ -791,11 +811,18 @@ function preLoadCss(cssUrl) {
         if (notable_ty) {
             wrapper.innerHTML = "<div class=\"content\">" +
                 window.NOTABLE_TRAITS[notable_ty] + "</div>";
-        } else if (e.getAttribute("title") !== undefined) {
-            const titleContent = document.createElement("div");
-            titleContent.className = "content";
-            titleContent.appendChild(document.createTextNode(e.getAttribute("title")));
-            wrapper.appendChild(titleContent);
+        } else {
+            // Replace any `title` attribute with `data-title` to avoid double tooltips.
+            if (e.getAttribute("title") !== null) {
+                e.setAttribute("data-title", e.getAttribute("title"));
+                e.removeAttribute("title");
+            }
+            if (e.getAttribute("data-title") !== null) {
+                const titleContent = document.createElement("div");
+                titleContent.className = "content";
+                titleContent.appendChild(document.createTextNode(e.getAttribute("data-title")));
+                wrapper.appendChild(titleContent);
+            }
         }
         wrapper.className = "tooltip popover";
         const focusCatcher = document.createElement("div");
@@ -824,17 +851,77 @@ function preLoadCss(cssUrl) {
         wrapper.style.visibility = "";
         window.CURRENT_TOOLTIP_ELEMENT = wrapper;
         window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE = e;
+        clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
+        wrapper.onpointerenter = function(ev) {
+            // If this is a synthetic touch event, ignore it. A click event will be along shortly.
+            if (ev.pointerType !== "mouse") {
+                return;
+            }
+            clearTooltipHoverTimeout(e);
+        };
         wrapper.onpointerleave = function(ev) {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            if (!e.TOOLTIP_FORCE_VISIBLE && !elemIsInParent(event.relatedTarget, e)) {
-                hideTooltip(true);
+            if (!e.TOOLTIP_FORCE_VISIBLE && !elemIsInParent(ev.relatedTarget, e)) {
+                // See "Tooltip pointer leave gesture" below.
+                setTooltipHoverTimeout(e, false);
+                addClass(wrapper, "fade-out");
             }
         };
     }
 
+    /**
+     * Show or hide the tooltip after a timeout. If a timeout was already set before this function
+     * was called, that timeout gets cleared. If the tooltip is already in the requested state,
+     * this function will still clear any pending timeout, but otherwise do nothing.
+     *
+     * @param {DOMElement} element - The tooltip's anchor point. The DOM is consulted to figure
+     *                               out what the tooltip should contain, and where it should be
+     *                               positioned.
+     * @param {boolean}    show    - If true, the tooltip will be made visible. If false, it will
+     *                               be hidden.
+     */
+    function setTooltipHoverTimeout(element, show) {
+        clearTooltipHoverTimeout(element);
+        if (!show && !window.CURRENT_TOOLTIP_ELEMENT) {
+            // To "hide" an already hidden element, just cancel its timeout.
+            return;
+        }
+        if (show && window.CURRENT_TOOLTIP_ELEMENT) {
+            // To "show" an already visible element, just cancel its timeout.
+            return;
+        }
+        if (window.CURRENT_TOOLTIP_ELEMENT &&
+            window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE !== element) {
+            // Don't do anything if another tooltip is already visible.
+            return;
+        }
+        element.TOOLTIP_HOVER_TIMEOUT = setTimeout(() => {
+            if (show) {
+                showTooltip(element);
+            } else if (!element.TOOLTIP_FORCE_VISIBLE) {
+                hideTooltip(false);
+            }
+        }, show ? window.RUSTDOC_TOOLTIP_HOVER_MS : window.RUSTDOC_TOOLTIP_HOVER_EXIT_MS);
+    }
+
+    /**
+     * If a show/hide timeout was set by `setTooltipHoverTimeout`, cancel it. If none exists,
+     * do nothing.
+     *
+     * @param {DOMElement} element - The tooltip's anchor point,
+     *                               as passed to `setTooltipHoverTimeout`.
+     */
+    function clearTooltipHoverTimeout(element) {
+        if (element.TOOLTIP_HOVER_TIMEOUT !== undefined) {
+            removeClass(window.CURRENT_TOOLTIP_ELEMENT, "fade-out");
+            clearTimeout(element.TOOLTIP_HOVER_TIMEOUT);
+            delete element.TOOLTIP_HOVER_TIMEOUT;
+        }
+    }
+
     function tooltipBlurHandler(event) {
         if (window.CURRENT_TOOLTIP_ELEMENT &&
             !elemIsInParent(document.activeElement, window.CURRENT_TOOLTIP_ELEMENT) &&
@@ -854,6 +941,12 @@ function preLoadCss(cssUrl) {
         }
     }
 
+    /**
+     * Hide the current tooltip immediately.
+     *
+     * @param {boolean} focus - If set to `true`, move keyboard focus to the tooltip anchor point.
+     *                          If set to `false`, leave keyboard focus alone.
+     */
     function hideTooltip(focus) {
         if (window.CURRENT_TOOLTIP_ELEMENT) {
             if (window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE.TOOLTIP_FORCE_VISIBLE) {
@@ -864,6 +957,7 @@ function preLoadCss(cssUrl) {
             }
             const body = document.getElementsByTagName("body")[0];
             body.removeChild(window.CURRENT_TOOLTIP_ELEMENT);
+            clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
             window.CURRENT_TOOLTIP_ELEMENT = null;
         }
     }
@@ -886,7 +980,14 @@ function preLoadCss(cssUrl) {
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            showTooltip(this);
+            setTooltipHoverTimeout(this, true);
+        };
+        e.onpointermove = function(ev) {
+            // If this is a synthetic touch event, ignore it. A click event will be along shortly.
+            if (ev.pointerType !== "mouse") {
+                return;
+            }
+            setTooltipHoverTimeout(this, true);
         };
         e.onpointerleave = function(ev) {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
@@ -895,7 +996,38 @@ function preLoadCss(cssUrl) {
             }
             if (!this.TOOLTIP_FORCE_VISIBLE &&
                 !elemIsInParent(ev.relatedTarget, window.CURRENT_TOOLTIP_ELEMENT)) {
-                hideTooltip(true);
+                // Tooltip pointer leave gesture:
+                //
+                // Designing a good hover microinteraction is a matter of guessing user
+                // intent from what are, literally, vague gestures. In this case, guessing if
+                // hovering in or out of the tooltip base is intentional or not.
+                //
+                // To figure this out, a few different techniques are used:
+                //
+                // * When the mouse pointer enters a tooltip anchor point, its hitbox is grown
+                //   on the bottom, where the popover is/will appear. Search "hover tunnel" in
+                //   rustdoc.css for the implementation.
+                // * There's a delay when the mouse pointer enters the popover base anchor, in
+                //   case the mouse pointer was just passing through and the user didn't want
+                //   to open it.
+                // * Similarly, a delay is added when exiting the anchor, or the popover
+                //   itself, before hiding it.
+                // * A fade-out animation is layered onto the pointer exit delay to immediately
+                //   inform the user that they successfully dismissed the popover, while still
+                //   providing a way for them to cancel it if it was a mistake and they still
+                //   wanted to interact with it.
+                // * No animation is used for revealing it, because we don't want people to try
+                //   to interact with an element while it's in the middle of fading in: either
+                //   they're allowed to interact with it while it's fading in, meaning it can't
+                //   serve as mistake-proofing for the popover, or they can't, but
+                //   they might try and be frustrated.
+                //
+                // See also:
+                // * https://www.nngroup.com/articles/timing-exposing-content/
+                // * https://www.nngroup.com/articles/tooltip-guidelines/
+                // * https://bjk5.com/post/44698559168/breaking-down-amazons-mega-dropdown
+                setTooltipHoverTimeout(e, false);
+                addClass(window.CURRENT_TOOLTIP_ELEMENT, "fade-out");
             }
         };
     });
@@ -918,9 +1050,10 @@ function preLoadCss(cssUrl) {
 
     function buildHelpMenu() {
         const book_info = document.createElement("span");
+        const channel = getVar("channel");
         book_info.className = "top";
-        book_info.innerHTML = "You can find more information in \
-            <a href=\"https://doc.rust-lang.org/rustdoc/\">the rustdoc book</a>.";
+        book_info.innerHTML = `You can find more information in \
+<a href="https://doc.rust-lang.org/${channel}/rustdoc/">the rustdoc book</a>.`;
 
         const shortcuts = [
             ["?", "Show this help dialog"],
@@ -940,6 +1073,9 @@ function preLoadCss(cssUrl) {
         div_shortcuts.innerHTML = "<h2>Keyboard Shortcuts</h2><dl>" + shortcuts + "</dl></div>";
 
         const infos = [
+            `For a full list of all search features, take a look <a \
+href="https://doc.rust-lang.org/${channel}/rustdoc/how-to-read-rustdoc.html\
+#the-search-interface">here</a>.`,
             "Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to \
              restrict the search to a given item kind.",
             "Accepted kinds are: <code>fn</code>, <code>mod</code>, <code>struct</code>, \
@@ -949,6 +1085,10 @@ function preLoadCss(cssUrl) {
              <code>-&gt; vec</code> or <code>String, enum:Cow -&gt; bool</code>)",
             "You can look for items with an exact name by putting double quotes around \
              your request: <code>\"string\"</code>",
+             "Look for functions that accept or return \
+              <a href=\"https://doc.rust-lang.org/std/primitive.slice.html\">slices</a> and \
+              <a href=\"https://doc.rust-lang.org/std/primitive.array.html\">arrays</a> by writing \
+              square brackets (e.g., <code>-&gt; [u8]</code> or <code>[] -&gt; Option</code>)",
             "Look for items inside another one by searching for a path: <code>vec::Vec</code>",
         ].map(x => "<p>" + x + "</p>").join("");
         const div_infos = document.createElement("div");
diff --git a/src/librustdoc/html/static/js/search.js b/src/librustdoc/html/static/js/search.js
index 62afe40bb..51d8e81ca 100644
--- a/src/librustdoc/html/static/js/search.js
+++ b/src/librustdoc/html/static/js/search.js
@@ -35,6 +35,35 @@ const itemTypes = [
     "traitalias",
 ];
 
+const longItemTypes = [
+    "module",
+    "extern crate",
+    "re-export",
+    "struct",
+    "enum",
+    "function",
+    "type alias",
+    "static",
+    "trait",
+    "",
+    "trait method",
+    "method",
+    "struct field",
+    "enum variant",
+    "macro",
+    "primitive type",
+    "assoc type",
+    "constant",
+    "assoc const",
+    "union",
+    "foreign type",
+    "keyword",
+    "existential type",
+    "attribute macro",
+    "derive macro",
+    "trait alias",
+];
+
 // used for special search precedence
 const TY_PRIMITIVE = itemTypes.indexOf("primitive");
 const TY_KEYWORD = itemTypes.indexOf("keyword");
@@ -208,6 +237,46 @@ function initSearch(rawSearchIndex) {
     let typeNameIdMap;
     const ALIASES = new Map();
 
+    /**
+     * Special type name IDs for searching by array.
+     */
+    let typeNameIdOfArray;
+    /**
+     * Special type name IDs for searching by slice.
+     */
+    let typeNameIdOfSlice;
+    /**
+     * Special type name IDs for searching by both array and slice (`[]` syntax).
+     */
+    let typeNameIdOfArrayOrSlice;
+
+    /**
+     * Add an item to the type Name->ID map, or, if one already exists, use it.
+     * Returns the number. If name is "" or null, return -1 (pure generic).
+     *
+     * This is effectively string interning, so that function matching can be
+     * done more quickly. Two types with the same name but different item kinds
+     * get the same ID.
+     *
+     * @param {string} name
+     *
+     * @returns {integer}
+     */
+    function buildTypeMapIndex(name) {
+
+        if (name === "" || name === null) {
+            return -1;
+        }
+
+        if (typeNameIdMap.has(name)) {
+            return typeNameIdMap.get(name);
+        } else {
+            const id = typeNameIdMap.size;
+            typeNameIdMap.set(name, id);
+            return id;
+        }
+    }
+
     function isWhitespace(c) {
         return " \t\n\r".indexOf(c) !== -1;
     }
@@ -217,11 +286,11 @@ function initSearch(rawSearchIndex) {
     }
 
     function isEndCharacter(c) {
-        return ",>-".indexOf(c) !== -1;
+        return ",>-]".indexOf(c) !== -1;
     }
 
     function isStopCharacter(c) {
-        return isWhitespace(c) || isEndCharacter(c);
+        return isEndCharacter(c);
     }
 
     function isErrorCharacter(c) {
@@ -317,18 +386,69 @@ function initSearch(rawSearchIndex) {
      * @return {boolean}
      */
     function isSeparatorCharacter(c) {
-        return c === "," || isWhitespaceCharacter(c);
+        return c === ",";
     }
 
-    /**
-     * Returns `true` if the given `c` character is a whitespace.
+/**
+     * Returns `true` if the given `c` character is a path separator. For example
+     * `:` in `a::b` or a whitespace in `a b`.
      *
      * @param {string} c
      *
      * @return {boolean}
      */
-    function isWhitespaceCharacter(c) {
-        return c === " " || c === "\t";
+    function isPathSeparator(c) {
+        return c === ":" || isWhitespace(c);
+    }
+
+    /**
+     * Returns `true` if the previous character is `lookingFor`.
+     *
+     * @param {ParserState} parserState
+     * @param {String} lookingFor
+     *
+     * @return {boolean}
+     */
+    function prevIs(parserState, lookingFor) {
+        let pos = parserState.pos;
+        while (pos > 0) {
+            const c = parserState.userQuery[pos - 1];
+            if (c === lookingFor) {
+                return true;
+            } else if (!isWhitespace(c)) {
+                break;
+            }
+            pos -= 1;
+        }
+        return false;
+    }
+
+    /**
+     * Returns `true` if the last element in the `elems` argument has generics.
+     *
+     * @param {Array<QueryElement>} elems
+     * @param {ParserState} parserState
+     *
+     * @return {boolean}
+     */
+    function isLastElemGeneric(elems, parserState) {
+        return (elems.length > 0 && elems[elems.length - 1].generics.length > 0) ||
+            prevIs(parserState, ">");
+    }
+
+    /**
+     * Increase current parser position until it doesn't find a whitespace anymore.
+     *
+     * @param {ParserState} parserState
+     */
+    function skipWhitespace(parserState) {
+        while (parserState.pos < parserState.userQuery.length) {
+            const c = parserState.userQuery[parserState.pos];
+            if (!isWhitespace(c)) {
+                break;
+            }
+            parserState.pos += 1;
+        }
     }
 
     /**
@@ -340,39 +460,78 @@ function initSearch(rawSearchIndex) {
      * @return {QueryElement}                - The newly created `QueryElement`.
      */
     function createQueryElement(query, parserState, name, generics, isInGenerics) {
-        if (name === "*" || (name.length === 0 && generics.length === 0)) {
-            return;
+        const path = name.trim();
+        if (path.length === 0 && generics.length === 0) {
+            throw ["Unexpected ", parserState.userQuery[parserState.pos]];
+        } else if (path === "*") {
+            throw ["Unexpected ", "*"];
         }
         if (query.literalSearch && parserState.totalElems - parserState.genericsElems > 0) {
-            throw ["You cannot have more than one element if you use quotes"];
-        }
-        const pathSegments = name.split("::");
-        if (pathSegments.length > 1) {
-            for (let i = 0, len = pathSegments.length; i < len; ++i) {
-                const pathSegment = pathSegments[i];
-
-                if (pathSegment.length === 0) {
-                    if (i === 0) {
-                        throw ["Paths cannot start with ", "::"];
-                    } else if (i + 1 === len) {
-                        throw ["Paths cannot end with ", "::"];
-                    }
-                    throw ["Unexpected ", "::::"];
-                }
+            throw ["Cannot have more than one element if you use quotes"];
+        }
+        const typeFilter = parserState.typeFilter;
+        parserState.typeFilter = null;
+        if (name === "!") {
+            if (typeFilter !== null && typeFilter !== "primitive") {
+                throw [
+                    "Invalid search type: primitive never type ",
+                    "!",
+                    " and ",
+                    typeFilter,
+                    " both specified",
+                ];
             }
+            if (generics.length !== 0) {
+                throw [
+                    "Never type ",
+                    "!",
+                    " does not accept generic parameters",
+                ];
+            }
+            return {
+                name: "never",
+                id: -1,
+                fullPath: ["never"],
+                pathWithoutLast: [],
+                pathLast: "never",
+                generics: [],
+                typeFilter: "primitive",
+            };
         }
+        if (path.startsWith("::")) {
+            throw ["Paths cannot start with ", "::"];
+        } else if (path.endsWith("::")) {
+            throw ["Paths cannot end with ", "::"];
+        } else if (path.includes("::::")) {
+            throw ["Unexpected ", "::::"];
+        } else if (path.includes(" ::")) {
+            throw ["Unexpected ", " ::"];
+        } else if (path.includes(":: ")) {
+            throw ["Unexpected ", ":: "];
+        }
+        const pathSegments = path.split(/::|\s+/);
         // In case we only have something like `<p>`, there is no name.
         if (pathSegments.length === 0 || (pathSegments.length === 1 && pathSegments[0] === "")) {
-            throw ["Found generics without a path"];
+            if (generics.length > 0 || prevIs(parserState, ">")) {
+                throw ["Found generics without a path"];
+            } else {
+                throw ["Unexpected ", parserState.userQuery[parserState.pos]];
+            }
+        }
+        for (const [i, pathSegment] of pathSegments.entries()) {
+            if (pathSegment === "!") {
+                if (i !== 0) {
+                    throw ["Never type ", "!", " is not associated item"];
+                }
+                pathSegments[i] = "never";
+            }
         }
         parserState.totalElems += 1;
         if (isInGenerics) {
             parserState.genericsElems += 1;
         }
-        const typeFilter = parserState.typeFilter;
-        parserState.typeFilter = null;
         return {
-            name: name,
+            name: name.trim(),
             id: -1,
             fullPath: pathSegments,
             pathWithoutLast: pathSegments.slice(0, pathSegments.length - 1),
@@ -408,28 +567,40 @@ function initSearch(rawSearchIndex) {
                     foundExclamation = parserState.pos;
                 } else if (isErrorCharacter(c)) {
                     throw ["Unexpected ", c];
-                } else if (
-                    isStopCharacter(c) ||
-                    isSpecialStartCharacter(c) ||
-                    isSeparatorCharacter(c)
-                ) {
-                    break;
-                } else if (c === ":") { // If we allow paths ("str::string" for example).
-                    if (!isPathStart(parserState)) {
-                        break;
+                } else if (isPathSeparator(c)) {
+                    if (c === ":") {
+                        if (!isPathStart(parserState)) {
+                            break;
+                        }
+                        // Skip current ":".
+                        parserState.pos += 1;
+                    } else {
+                        while (parserState.pos + 1 < parserState.length) {
+                            const next_c = parserState.userQuery[parserState.pos + 1];
+                            if (!isWhitespace(next_c)) {
+                                break;
+                            }
+                            parserState.pos += 1;
+                        }
                     }
                     if (foundExclamation !== -1) {
-                        if (start <= (end - 2)) {
+                        if (foundExclamation !== start &&
+                            isIdentCharacter(parserState.userQuery[foundExclamation - 1])
+                        ) {
                             throw ["Cannot have associated items in macros"];
                         } else {
-                            // if start == end - 1, we got the never type
                             // while the never type has no associated macros, we still
                             // can parse a path like that
                             foundExclamation = -1;
                         }
                     }
-                    // Skip current ":".
-                    parserState.pos += 1;
+                } else if (
+                    c === "[" ||
+                    isStopCharacter(c) ||
+                    isSpecialStartCharacter(c) ||
+                    isSeparatorCharacter(c)
+                ) {
+                    break;
                 } else {
                     throw ["Unexpected ", c];
                 }
@@ -438,7 +609,10 @@ function initSearch(rawSearchIndex) {
             end = parserState.pos;
         }
         // if start == end - 1, we got the never type
-        if (foundExclamation !== -1 && start <= (end - 2)) {
+        if (foundExclamation !== -1 &&
+            foundExclamation !== start &&
+            isIdentCharacter(parserState.userQuery[foundExclamation - 1])
+        ) {
             if (parserState.typeFilter === null) {
                 parserState.typeFilter = "macro";
             } else if (parserState.typeFilter !== "macro") {
@@ -464,37 +638,71 @@ function initSearch(rawSearchIndex) {
     function getNextElem(query, parserState, elems, isInGenerics) {
         const generics = [];
 
+        skipWhitespace(parserState);
         let start = parserState.pos;
         let end;
-        // We handle the strings on their own mostly to make code easier to follow.
-        if (parserState.userQuery[parserState.pos] === "\"") {
-            start += 1;
-            getStringElem(query, parserState, isInGenerics);
-            end = parserState.pos - 1;
+        if (parserState.userQuery[parserState.pos] === "[") {
+            parserState.pos += 1;
+            getItemsBefore(query, parserState, generics, "]");
+            const typeFilter = parserState.typeFilter;
+            if (typeFilter !== null && typeFilter !== "primitive") {
+                throw [
+                    "Invalid search type: primitive ",
+                    "[]",
+                    " and ",
+                    typeFilter,
+                    " both specified",
+                ];
+            }
+            parserState.typeFilter = null;
+            parserState.totalElems += 1;
+            if (isInGenerics) {
+                parserState.genericsElems += 1;
+            }
+            elems.push({
+                name: "[]",
+                id: -1,
+                fullPath: ["[]"],
+                pathWithoutLast: [],
+                pathLast: "[]",
+                generics,
+                typeFilter: "primitive",
+            });
         } else {
-            end = getIdentEndPosition(parserState);
-        }
-        if (parserState.pos < parserState.length &&
-            parserState.userQuery[parserState.pos] === "<"
-        ) {
-            if (start >= end) {
-                throw ["Found generics without a path"];
+            const isStringElem = parserState.userQuery[start] === "\"";
+            // We handle the strings on their own mostly to make code easier to follow.
+            if (isStringElem) {
+                start += 1;
+                getStringElem(query, parserState, isInGenerics);
+                end = parserState.pos - 1;
+            } else {
+                end = getIdentEndPosition(parserState);
             }
-            parserState.pos += 1;
-            getItemsBefore(query, parserState, generics, ">");
-        }
-        if (start >= end && generics.length === 0) {
-            return;
+            if (parserState.pos < parserState.length &&
+                parserState.userQuery[parserState.pos] === "<"
+            ) {
+                if (start >= end) {
+                    throw ["Found generics without a path"];
+                }
+                parserState.pos += 1;
+                getItemsBefore(query, parserState, generics, ">");
+            }
+            if (isStringElem) {
+                skipWhitespace(parserState);
+            }
+            if (start >= end && generics.length === 0) {
+                return;
+            }
+            elems.push(
+                createQueryElement(
+                    query,
+                    parserState,
+                    parserState.userQuery.slice(start, end),
+                    generics,
+                    isInGenerics
+                )
+            );
         }
-        elems.push(
-            createQueryElement(
-                query,
-                parserState,
-                parserState.userQuery.slice(start, end),
-                generics,
-                isInGenerics
-            )
-        );
     }
 
     /**
@@ -518,6 +726,17 @@ function initSearch(rawSearchIndex) {
         const oldTypeFilter = parserState.typeFilter;
         parserState.typeFilter = null;
 
+        let extra = "";
+        if (endChar === ">") {
+            extra = "<";
+        } else if (endChar === "]") {
+            extra = "[";
+        } else if (endChar === "") {
+            extra = "->";
+        } else {
+            extra = endChar;
+        }
+
         while (parserState.pos < parserState.length) {
             const c = parserState.userQuery[parserState.pos];
             if (c === endChar) {
@@ -535,7 +754,7 @@ function initSearch(rawSearchIndex) {
                 if (elems.length === 0) {
                     throw ["Expected type filter before ", ":"];
                 } else if (query.literalSearch) {
-                    throw ["You cannot use quotes on type filter"];
+                    throw ["Cannot use quotes on type filter"];
                 }
                 // The type filter doesn't count as an element since it's a modifier.
                 const typeFilterElem = elems.pop();
@@ -547,43 +766,39 @@ function initSearch(rawSearchIndex) {
                 foundStopChar = true;
                 continue;
             } else if (isEndCharacter(c)) {
-                let extra = "";
-                if (endChar === ">") {
-                    extra = "<";
-                } else if (endChar === "") {
-                    extra = "->";
-                } else {
-                    extra = endChar;
-                }
                 throw ["Unexpected ", c, " after ", extra];
             }
             if (!foundStopChar) {
+                let extra = [];
+                if (isLastElemGeneric(query.elems, parserState)) {
+                    extra = [" after ", ">"];
+                } else if (prevIs(parserState, "\"")) {
+                    throw ["Cannot have more than one element if you use quotes"];
+                }
                 if (endChar !== "") {
                     throw [
                         "Expected ",
-                        ",", // comma
-                        ", ",
-                        "&nbsp;", // whitespace
+                        ",",
                         " or ",
                         endChar,
+                        ...extra,
                         ", found ",
                         c,
                     ];
                 }
                 throw [
                     "Expected ",
-                    ",", // comma
-                    " or ",
-                    "&nbsp;", // whitespace
+                    ",",
+                    ...extra,
                     ", found ",
                     c,
                 ];
             }
             const posBefore = parserState.pos;
             start = parserState.pos;
-            getNextElem(query, parserState, elems, endChar === ">");
+            getNextElem(query, parserState, elems, endChar !== "");
             if (endChar !== "" && parserState.pos >= parserState.length) {
-                throw ["Unclosed ", "<"];
+                throw ["Unclosed ", extra];
             }
             // This case can be encountered if `getNextElem` encountered a "stop character" right
             // from the start. For example if you have `,,` or `<>`. In this case, we simply move up
@@ -594,7 +809,7 @@ function initSearch(rawSearchIndex) {
             foundStopChar = false;
         }
         if (parserState.pos >= parserState.length && endChar !== "") {
-            throw ["Unclosed ", "<"];
+            throw ["Unclosed ", extra];
         }
         // We are either at the end of the string or on the `endChar` character, let's move forward
         // in any case.
@@ -610,11 +825,17 @@ function initSearch(rawSearchIndex) {
      * @param {ParserState} parserState
      */
     function checkExtraTypeFilterCharacters(start, parserState) {
-        const query = parserState.userQuery;
+        const query = parserState.userQuery.slice(start, parserState.pos).trim();
 
-        for (let pos = start; pos < parserState.pos; ++pos) {
-            if (!isIdentCharacter(query[pos]) && !isWhitespaceCharacter(query[pos])) {
-                throw ["Unexpected ", query[pos], " in type filter"];
+        for (const c in query) {
+            if (!isIdentCharacter(query[c])) {
+                throw [
+                    "Unexpected ",
+                    query[c],
+                    " in type filter (before ",
+                    ":",
+                    ")",
+                ];
             }
         }
     }
@@ -646,12 +867,17 @@ function initSearch(rawSearchIndex) {
                 throw ["Unexpected ", c];
             } else if (c === ":" && !isPathStart(parserState)) {
                 if (parserState.typeFilter !== null) {
-                    throw ["Unexpected ", ":"];
-                }
-                if (query.elems.length === 0) {
+                    throw [
+                        "Unexpected ",
+                        ":",
+                        " (expected path after type filter ",
+                        parserState.typeFilter + ":",
+                        ")",
+                    ];
+                } else if (query.elems.length === 0) {
                     throw ["Expected type filter before ", ":"];
                 } else if (query.literalSearch) {
-                    throw ["You cannot use quotes on type filter"];
+                    throw ["Cannot use quotes on type filter"];
                 }
                 // The type filter doesn't count as an element since it's a modifier.
                 const typeFilterElem = query.elems.pop();
@@ -662,29 +888,36 @@ function initSearch(rawSearchIndex) {
                 query.literalSearch = false;
                 foundStopChar = true;
                 continue;
+            } else if (isWhitespace(c)) {
+                skipWhitespace(parserState);
+                continue;
             }
             if (!foundStopChar) {
+                let extra = "";
+                if (isLastElemGeneric(query.elems, parserState)) {
+                    extra = [" after ", ">"];
+                } else if (prevIs(parserState, "\"")) {
+                    throw ["Cannot have more than one element if you use quotes"];
+                }
                 if (parserState.typeFilter !== null) {
                     throw [
                         "Expected ",
-                        ",", // comma
-                        ", ",
-                        "&nbsp;", // whitespace
+                        ",",
                         " or ",
-                        "->", // arrow
+                        "->",
+                        ...extra,
                         ", found ",
                         c,
                     ];
                 }
                 throw [
                     "Expected ",
-                    ",", // comma
+                    ",",
                     ", ",
-                    "&nbsp;", // whitespace
-                    ", ",
-                    ":", // colon
+                    ":",
                     " or ",
-                    "->", // arrow
+                    "->",
+                    ...extra,
                     ", found ",
                     c,
                 ];
@@ -699,11 +932,18 @@ function initSearch(rawSearchIndex) {
             foundStopChar = false;
         }
         if (parserState.typeFilter !== null) {
-            throw ["Unexpected ", ":", " (expected path after type filter)"];
+            throw [
+                "Unexpected ",
+                ":",
+                " (expected path after type filter ",
+                parserState.typeFilter + ":",
+                ")",
+            ];
         }
         while (parserState.pos < parserState.length) {
             if (isReturnArrow(parserState)) {
                 parserState.pos += 2;
+                skipWhitespace(parserState);
                 // Get returned elements.
                 getItemsBefore(query, parserState, query.returned, "");
                 // Nothing can come afterward!
@@ -778,9 +1018,10 @@ function initSearch(rawSearchIndex) {
      * The supported syntax by this parser is as follow:
      *
      * ident = *(ALPHA / DIGIT / "_")
-     * path = ident *(DOUBLE-COLON ident) [!]
-     * arg = [type-filter *WS COLON *WS] path [generics]
-     * type-sep = COMMA/WS *(COMMA/WS)
+     * path = ident *(DOUBLE-COLON/{WS} ident) [!]
+     * slice = OPEN-SQUARE-BRACKET [ nonempty-arg-list ] CLOSE-SQUARE-BRACKET
+     * arg = [type-filter *WS COLON *WS] (path [generics] / slice)
+     * type-sep = *WS COMMA *(COMMA)
      * nonempty-arg-list = *(type-sep) arg *(type-sep arg) *(type-sep)
      * generics = OPEN-ANGLE-BRACKET [ nonempty-arg-list ] *(type-sep)
      *            CLOSE-ANGLE-BRACKET
@@ -821,6 +1062,8 @@ function initSearch(rawSearchIndex) {
      *
      * OPEN-ANGLE-BRACKET = "<"
      * CLOSE-ANGLE-BRACKET = ">"
+     * OPEN-SQUARE-BRACKET = "["
+     * CLOSE-SQUARE-BRACKET = "]"
      * COLON = ":"
      * DOUBLE-COLON = "::"
      * QUOTE = %x22
@@ -1103,98 +1346,182 @@ function initSearch(rawSearchIndex) {
         }
 
         /**
-         * This function checks if the object (`row`) generics match the given type (`elem`)
-         * generics. If there are no generics on `row`, `defaultDistance` is returned.
+         * This function checks generics in search query `queryElem` can all be found in the
+         * search index (`fnType`),
          *
-         * @param {Row} row                 - The object to check.
-         * @param {QueryElement} elem       - The element from the parsed query.
+         * @param {FunctionType} fnType     - The object to check.
+         * @param {QueryElement} queryElem  - The element from the parsed query.
          *
-         * @return {boolean}           - Returns true if a match, false otherwise.
+         * @return {boolean} - Returns true if a match, false otherwise.
          */
-        function checkGenerics(row, elem) {
-            if (row.generics.length === 0 || elem.generics.length === 0) {
-                return false;
-            }
-            // This function is called if the names match, but we need to make
-            // sure that all generics match as well.
-            //
+        function checkGenerics(fnType, queryElem) {
+            return unifyFunctionTypes(fnType.generics, queryElem.generics);
+        }
+        /**
+         * This function checks if a list of search query `queryElems` can all be found in the
+         * search index (`fnTypes`).
+         *
+         * @param {Array<FunctionType>} fnTypes    - The objects to check.
+         * @param {Array<QueryElement>} queryElems - The elements from the parsed query.
+         *
+         * @return {boolean} - Returns true if a match, false otherwise.
+         */
+        function unifyFunctionTypes(fnTypes, queryElems) {
             // This search engine implements order-agnostic unification. There
             // should be no missing duplicates (generics have "bag semantics"),
             // and the row is allowed to have extras.
-            if (elem.generics.length > 0 && row.generics.length >= elem.generics.length) {
-                const elems = new Map();
-                const addEntryToElems = function addEntryToElems(entry) {
-                    if (entry.id === -1) {
-                        // Pure generic, needs to check into it.
-                        for (const inner_entry of entry.generics) {
-                            addEntryToElems(inner_entry);
-                        }
-                        return;
+            if (queryElems.length === 0) {
+                return true;
+            }
+            if (!fnTypes || fnTypes.length === 0) {
+                return false;
+            }
+            /**
+             * @type Map<integer, QueryElement[]>
+             */
+            const queryElemSet = new Map();
+            const addQueryElemToQueryElemSet = function addQueryElemToQueryElemSet(queryElem) {
+                let currentQueryElemList;
+                if (queryElemSet.has(queryElem.id)) {
+                    currentQueryElemList = queryElemSet.get(queryElem.id);
+                } else {
+                    currentQueryElemList = [];
+                    queryElemSet.set(queryElem.id, currentQueryElemList);
+                }
+                currentQueryElemList.push(queryElem);
+            };
+            for (const queryElem of queryElems) {
+                addQueryElemToQueryElemSet(queryElem);
+            }
+            /**
+             * @type Map<integer, FunctionType[]>
+             */
+            const fnTypeSet = new Map();
+            const addFnTypeToFnTypeSet = function addFnTypeToFnTypeSet(fnType) {
+                // Pure generic, or an item that's not matched by any query elems.
+                // Try [unboxing] it.
+                //
+                // [unboxing]:
+                // http://ndmitchell.com/downloads/slides-hoogle_fast_type_searching-09_aug_2008.pdf
+                const queryContainsArrayOrSliceElem = queryElemSet.has(typeNameIdOfArrayOrSlice);
+                if (fnType.id === -1 || !(
+                    queryElemSet.has(fnType.id) ||
+                    (fnType.id === typeNameIdOfSlice && queryContainsArrayOrSliceElem) ||
+                    (fnType.id === typeNameIdOfArray && queryContainsArrayOrSliceElem)
+                )) {
+                    for (const innerFnType of fnType.generics) {
+                        addFnTypeToFnTypeSet(innerFnType);
                     }
-                    let currentEntryElems;
-                    if (elems.has(entry.id)) {
-                        currentEntryElems = elems.get(entry.id);
-                    } else {
-                        currentEntryElems = [];
-                        elems.set(entry.id, currentEntryElems);
+                    return;
+                }
+                let currentQueryElemList = queryElemSet.get(fnType.id) || [];
+                let matchIdx = currentQueryElemList.findIndex(queryElem => {
+                    return typePassesFilter(queryElem.typeFilter, fnType.ty) &&
+                        checkGenerics(fnType, queryElem);
+                });
+                if (matchIdx === -1 &&
+                    (fnType.id === typeNameIdOfSlice || fnType.id === typeNameIdOfArray) &&
+                    queryContainsArrayOrSliceElem
+                ) {
+                    currentQueryElemList = queryElemSet.get(typeNameIdOfArrayOrSlice) || [];
+                    matchIdx = currentQueryElemList.findIndex(queryElem => {
+                        return typePassesFilter(queryElem.typeFilter, fnType.ty) &&
+                            checkGenerics(fnType, queryElem);
+                    });
+                }
+                // None of the query elems match the function type.
+                // Try [unboxing] it.
+                if (matchIdx === -1) {
+                    for (const innerFnType of fnType.generics) {
+                        addFnTypeToFnTypeSet(innerFnType);
                     }
-                    currentEntryElems.push(entry);
-                };
-                for (const entry of row.generics) {
-                    addEntryToElems(entry);
-                }
-                // We need to find the type that matches the most to remove it in order
-                // to move forward.
-                const handleGeneric = generic => {
-                    if (!elems.has(generic.id)) {
-                        return false;
+                    return;
+                }
+                let currentFnTypeList;
+                if (fnTypeSet.has(fnType.id)) {
+                    currentFnTypeList = fnTypeSet.get(fnType.id);
+                } else {
+                    currentFnTypeList = [];
+                    fnTypeSet.set(fnType.id, currentFnTypeList);
+                }
+                currentFnTypeList.push(fnType);
+            };
+            for (const fnType of fnTypes) {
+                addFnTypeToFnTypeSet(fnType);
+            }
+            const doHandleQueryElemList = (currentFnTypeList, queryElemList) => {
+                if (queryElemList.length === 0) {
+                    return true;
+                }
+                // Multiple items in one list might match multiple items in another.
+                // Since an item with fewer generics can match an item with more, we
+                // need to check all combinations for a potential match.
+                const queryElem = queryElemList.pop();
+                const l = currentFnTypeList.length;
+                for (let i = 0; i < l; i += 1) {
+                    const fnType = currentFnTypeList[i];
+                    if (!typePassesFilter(queryElem.typeFilter, fnType.ty)) {
+                        continue;
                     }
-                    const matchElems = elems.get(generic.id);
-                    const matchIdx = matchElems.findIndex(tmp_elem => {
-                        if (generic.generics.length > 0 && !checkGenerics(tmp_elem, generic)) {
-                            return false;
+                    if (queryElem.generics.length === 0 || checkGenerics(fnType, queryElem)) {
+                        currentFnTypeList.splice(i, 1);
+                        const result = doHandleQueryElemList(currentFnTypeList, queryElemList);
+                        if (result) {
+                            return true;
                         }
-                        return typePassesFilter(generic.typeFilter, tmp_elem.ty);
-                    });
-                    if (matchIdx === -1) {
-                        return false;
+                        currentFnTypeList.splice(i, 0, fnType);
                     }
-                    matchElems.splice(matchIdx, 1);
-                    if (matchElems.length === 0) {
-                        elems.delete(generic.id);
+                }
+                return false;
+            };
+            const handleQueryElemList = (id, queryElemList) => {
+                if (!fnTypeSet.has(id)) {
+                    if (id === typeNameIdOfArrayOrSlice) {
+                        return handleQueryElemList(typeNameIdOfSlice, queryElemList) ||
+                            handleQueryElemList(typeNameIdOfArray, queryElemList);
                     }
-                    return true;
-                };
-                // To do the right thing with type filters, we first process generics
-                // that have them, removing matching ones from the "bag," then do the
-                // ones with no type filter, which can match any entry regardless of its
-                // own type.
-                for (const generic of elem.generics) {
-                    if (generic.typeFilter !== -1 && !handleGeneric(generic)) {
-                        return false;
+                    return false;
+                }
+                const currentFnTypeList = fnTypeSet.get(id);
+                if (currentFnTypeList.length < queryElemList.length) {
+                    // It's not possible for all the query elems to find a match.
+                    return false;
+                }
+                const result = doHandleQueryElemList(currentFnTypeList, queryElemList);
+                if (result) {
+                    // Found a solution.
+                    // Any items that weren't used for it can be unboxed, and might form
+                    // part of the solution for another item.
+                    for (const innerFnType of currentFnTypeList) {
+                        addFnTypeToFnTypeSet(innerFnType);
                     }
+                    fnTypeSet.delete(id);
                 }
-                for (const generic of elem.generics) {
-                    if (generic.typeFilter === -1 && !handleGeneric(generic)) {
-                        return false;
+                return result;
+            };
+            let queryElemSetSize = -1;
+            while (queryElemSetSize !== queryElemSet.size) {
+                queryElemSetSize = queryElemSet.size;
+                for (const [id, queryElemList] of queryElemSet) {
+                    if (handleQueryElemList(id, queryElemList)) {
+                        queryElemSet.delete(id);
                     }
                 }
-                return true;
             }
-            return false;
+            return queryElemSetSize === 0;
         }
 
         /**
           * This function checks if the object (`row`) matches the given type (`elem`) and its
           * generics (if any).
           *
-          * @param {Row} row
+          * @param {Array<FunctionType>} list
           * @param {QueryElement} elem    - The element from the parsed query.
           *
           * @return {boolean} - Returns true if found, false otherwise.
           */
-        function checkIfInGenerics(row, elem) {
-            for (const entry of row.generics) {
+        function checkIfInList(list, elem) {
+            for (const entry of list) {
                 if (checkType(entry, elem)) {
                     return true;
                 }
@@ -1214,10 +1541,15 @@ function initSearch(rawSearchIndex) {
         function checkType(row, elem) {
             if (row.id === -1) {
                 // This is a pure "generic" search, no need to run other checks.
-                return row.generics.length > 0 ? checkIfInGenerics(row, elem) : false;
+                return row.generics.length > 0 ? checkIfInList(row.generics, elem) : false;
             }
 
-            if (row.id === elem.id && typePassesFilter(elem.typeFilter, row.ty)) {
+            const matchesExact = row.id === elem.id;
+            const matchesArrayOrSlice = elem.id === typeNameIdOfArrayOrSlice &&
+                (row.id === typeNameIdOfSlice || row.id === typeNameIdOfArray);
+
+            if ((matchesExact || matchesArrayOrSlice) &&
+                typePassesFilter(elem.typeFilter, row.ty)) {
                 if (elem.generics.length > 0) {
                     return checkGenerics(row, elem);
                 }
@@ -1227,59 +1559,7 @@ function initSearch(rawSearchIndex) {
             // If the current item does not match, try [unboxing] the generic.
             // [unboxing]:
             //   https://ndmitchell.com/downloads/slides-hoogle_fast_type_searching-09_aug_2008.pdf
-            return checkIfInGenerics(row, elem);
-        }
-
-        /**
-         * This function checks if the object (`row`) has an argument with the given type (`elem`).
-         *
-         * @param {Row} row
-         * @param {QueryElement} elem    - The element from the parsed query.
-         * @param {Array<integer>} skipPositions - Do not return one of these positions.
-         *
-         * @return {integer} - Returns the position of the match, or -1 if none.
-         */
-        function findArg(row, elem, skipPositions) {
-            if (row && row.type && row.type.inputs && row.type.inputs.length > 0) {
-                let i = 0;
-                for (const input of row.type.inputs) {
-                    if (skipPositions.indexOf(i) !== -1) {
-                        i += 1;
-                        continue;
-                    }
-                    if (checkType(input, elem)) {
-                        return i;
-                    }
-                    i += 1;
-                }
-            }
-            return -1;
-        }
-
-        /**
-         * This function checks if the object (`row`) returns the given type (`elem`).
-         *
-         * @param {Row} row
-         * @param {QueryElement} elem   - The element from the parsed query.
-         * @param {Array<integer>} skipPositions - Do not return one of these positions.
-         *
-         * @return {integer} - Returns the position of the matching item, or -1 if none.
-         */
-        function checkReturned(row, elem, skipPositions) {
-            if (row && row.type && row.type.output.length > 0) {
-                let i = 0;
-                for (const ret_ty of row.type.output) {
-                    if (skipPositions.indexOf(i) !== -1) {
-                        i += 1;
-                        continue;
-                    }
-                    if (checkType(ret_ty, elem)) {
-                        return i;
-                    }
-                    i += 1;
-                }
-            }
-            return -1;
+            return checkIfInList(row.generics, elem);
         }
 
         function checkPath(contains, ty, maxEditDistance) {
@@ -1480,14 +1760,14 @@ function initSearch(rawSearchIndex) {
             const fullId = row.id;
             const searchWord = searchWords[pos];
 
-            const in_args = findArg(row, elem, []);
-            if (in_args !== -1) {
+            const in_args = row.type && row.type.inputs && checkIfInList(row.type.inputs, elem);
+            if (in_args) {
                 // path_dist is 0 because no parent path information is currently stored
                 // in the search index
                 addIntoResults(results_in_args, fullId, pos, -1, 0, 0, maxEditDistance);
             }
-            const returned = checkReturned(row, elem, []);
-            if (returned !== -1) {
+            const returned = row.type && row.type.output && checkIfInList(row.type.output, elem);
+            if (returned) {
                 addIntoResults(results_returned, fullId, pos, -1, 0, 0, maxEditDistance);
             }
 
@@ -1543,32 +1823,15 @@ function initSearch(rawSearchIndex) {
          * @param {Object} results
          */
         function handleArgs(row, pos, results) {
-            if (!row || (filterCrates !== null && row.crate !== filterCrates)) {
+            if (!row || (filterCrates !== null && row.crate !== filterCrates) || !row.type) {
                 return;
             }
 
             // If the result is too "bad", we return false and it ends this search.
-            function checkArgs(elems, callback) {
-                const skipPositions = [];
-                for (const elem of elems) {
-                    // There is more than one parameter to the query so all checks should be "exact"
-                    const position = callback(
-                        row,
-                        elem,
-                        skipPositions
-                    );
-                    if (position !== -1) {
-                        skipPositions.push(position);
-                    } else {
-                        return false;
-                    }
-                }
-                return true;
-            }
-            if (!checkArgs(parsedQuery.elems, findArg)) {
+            if (!unifyFunctionTypes(row.type.inputs, parsedQuery.elems)) {
                 return;
             }
-            if (!checkArgs(parsedQuery.returned, checkReturned)) {
+            if (!unifyFunctionTypes(row.type.output, parsedQuery.returned)) {
                 return;
             }
 
@@ -1655,12 +1918,9 @@ function initSearch(rawSearchIndex) {
                     elem = parsedQuery.returned[0];
                     for (i = 0, nSearchWords = searchWords.length; i < nSearchWords; ++i) {
                         row = searchIndex[i];
-                        in_returned = checkReturned(
-                            row,
-                            elem,
-                            []
-                        );
-                        if (in_returned !== -1) {
+                        in_returned = row.type &&
+                            unifyFunctionTypes(row.type.output, parsedQuery.returned);
+                        if (in_returned) {
                             addIntoResults(
                                 results_others,
                                 row.id,
@@ -1836,16 +2096,11 @@ function initSearch(rawSearchIndex) {
             array.forEach(item => {
                 const name = item.name;
                 const type = itemTypes[item.ty];
+                const longType = longItemTypes[item.ty];
+                const typeName = longType.length !== 0 ? `${longType}` : "?";
 
                 length += 1;
 
-                let extra = "";
-                if (type === "primitive") {
-                    extra = " <i>(primitive type)</i>";
-                } else if (type === "keyword") {
-                    extra = " <i>(keyword)</i>";
-                }
-
                 const link = document.createElement("a");
                 link.className = "result-" + type;
                 link.href = item.href;
@@ -1863,13 +2118,18 @@ function initSearch(rawSearchIndex) {
 
                     alias.insertAdjacentHTML(
                         "beforeend",
-                        "<span class=\"grey\"><i>&nbsp;- see&nbsp;</i></span>");
+                        "<i class=\"grey\">&nbsp;- see&nbsp;</i>");
 
                     resultName.appendChild(alias);
                 }
+
                 resultName.insertAdjacentHTML(
                     "beforeend",
-                    item.displayPath + "<span class=\"" + type + "\">" + name + extra + "</span>");
+                    `\
+<span class="typename">${typeName}</span>\
+<div class="path">\
+ ${item.displayPath}<span class="${type}">${name}</span>\
+</div>`);
                 link.appendChild(resultName);
 
                 const description = document.createElement("div");
@@ -1916,6 +2176,20 @@ function initSearch(rawSearchIndex) {
         if (go_to_first || (results.others.length === 1
             && getSettingValue("go-to-only-result") === "true")
         ) {
+            // Needed to force re-execution of JS when coming back to a page. Let's take this
+            // scenario as example:
+            //
+            // 1. You have the "Directly go to item in search if there is only one result" option
+            //    enabled.
+            // 2. You make a search which results only one result, leading you automatically to
+            //    this result.
+            // 3. You go back to previous page.
+            //
+            // Now, without the call below, the JS will not be re-executed and the previous state
+            // will be used, starting search again since the search input is not empty, leading you
+            // back to the previous page again.
+            window.onunload = () => {};
+            searchState.removeQueryParameters();
             const elem = document.createElement("a");
             elem.href = results.others[0].href;
             removeClass(elem, "active");
@@ -1967,7 +2241,7 @@ function initSearch(rawSearchIndex) {
             error.forEach((value, index) => {
                 value = value.split("<").join("&lt;").split(">").join("&gt;");
                 if (index % 2 !== 0) {
-                    error[index] = `<code>${value}</code>`;
+                    error[index] = `<code>${value.replaceAll(" ", "&nbsp;")}</code>`;
                 } else {
                     error[index] = value;
                 }
@@ -2030,6 +2304,18 @@ function initSearch(rawSearchIndex) {
         printTab(currentTab);
     }
 
+    function updateSearchHistory(url) {
+        if (!browserSupportsHistoryApi()) {
+            return;
+        }
+        const params = searchState.getQueryStringParams();
+        if (!history.state && !params.search) {
+            history.pushState(null, "", url);
+        } else {
+            history.replaceState(null, "", url);
+        }
+    }
+
     /**
      * Perform a search based on the current state of the search input element
      * and display the results.
@@ -2040,7 +2326,6 @@ function initSearch(rawSearchIndex) {
         if (e) {
             e.preventDefault();
         }
-
         const query = parseQuery(searchState.input.value.trim());
         let filterCrates = getFilterCrates();
 
@@ -2066,15 +2351,7 @@ function initSearch(rawSearchIndex) {
 
         // Because searching is incremental by character, only the most
         // recent search query is added to the browser history.
-        if (browserSupportsHistoryApi()) {
-            const newURL = buildUrl(query.original, filterCrates);
-
-            if (!history.state && !params.search) {
-                history.pushState(null, "", newURL);
-            } else {
-                history.replaceState(null, "", newURL);
-            }
-        }
+        updateSearchHistory(buildUrl(query.original, filterCrates));
 
         showResults(
             execQuery(query, searchWords, filterCrates, window.currentCrate),
@@ -2083,34 +2360,6 @@ function initSearch(rawSearchIndex) {
     }
 
     /**
-     * Add an item to the type Name->ID map, or, if one already exists, use it.
-     * Returns the number. If name is "" or null, return -1 (pure generic).
-     *
-     * This is effectively string interning, so that function matching can be
-     * done more quickly. Two types with the same name but different item kinds
-     * get the same ID.
-     *
-     * @param {Map<string, integer>} typeNameIdMap
-     * @param {string} name
-     *
-     * @returns {integer}
-     */
-    function buildTypeMapIndex(typeNameIdMap, name) {
-
-        if (name === "" || name === null) {
-            return -1;
-        }
-
-        if (typeNameIdMap.has(name)) {
-            return typeNameIdMap.get(name);
-        } else {
-            const id = typeNameIdMap.size;
-            typeNameIdMap.set(name, id);
-            return id;
-        }
-    }
-
-    /**
      * Convert a list of RawFunctionType / ID to object-based FunctionType.
      *
      * Crates often have lots of functions in them, and it's common to have a large number of
@@ -2128,7 +2377,7 @@ function initSearch(rawSearchIndex) {
      *
      * @return {Array<FunctionSearchType>}
      */
-    function buildItemSearchTypeAll(types, lowercasePaths, typeNameIdMap) {
+    function buildItemSearchTypeAll(types, lowercasePaths) {
         const PATH_INDEX_DATA = 0;
         const GENERICS_DATA = 1;
         return types.map(type => {
@@ -2140,15 +2389,14 @@ function initSearch(rawSearchIndex) {
                 pathIndex = type[PATH_INDEX_DATA];
                 generics = buildItemSearchTypeAll(
                     type[GENERICS_DATA],
-                    lowercasePaths,
-                    typeNameIdMap
+                    lowercasePaths
                 );
             }
             return {
                 // `0` is used as a sentinel because it's fewer bytes than `null`
                 id: pathIndex === 0
                     ? -1
-                    : buildTypeMapIndex(typeNameIdMap, lowercasePaths[pathIndex - 1].name),
+                    : buildTypeMapIndex(lowercasePaths[pathIndex - 1].name),
                 ty: pathIndex === 0 ? null : lowercasePaths[pathIndex - 1].ty,
                 generics: generics,
             };
@@ -2171,7 +2419,7 @@ function initSearch(rawSearchIndex) {
      *
      * @return {null|FunctionSearchType}
      */
-    function buildFunctionSearchType(functionSearchType, lowercasePaths, typeNameIdMap) {
+    function buildFunctionSearchType(functionSearchType, lowercasePaths) {
         const INPUTS_DATA = 0;
         const OUTPUT_DATA = 1;
         // `0` is used as a sentinel because it's fewer bytes than `null`
@@ -2184,15 +2432,14 @@ function initSearch(rawSearchIndex) {
             inputs = [{
                 id: pathIndex === 0
                     ? -1
-                    : buildTypeMapIndex(typeNameIdMap, lowercasePaths[pathIndex - 1].name),
+                    : buildTypeMapIndex(lowercasePaths[pathIndex - 1].name),
                 ty: pathIndex === 0 ? null : lowercasePaths[pathIndex - 1].ty,
                 generics: [],
             }];
         } else {
             inputs = buildItemSearchTypeAll(
                 functionSearchType[INPUTS_DATA],
-                lowercasePaths,
-                typeNameIdMap
+                lowercasePaths
             );
         }
         if (functionSearchType.length > 1) {
@@ -2201,15 +2448,14 @@ function initSearch(rawSearchIndex) {
                 output = [{
                     id: pathIndex === 0
                         ? -1
-                        : buildTypeMapIndex(typeNameIdMap, lowercasePaths[pathIndex - 1].name),
+                        : buildTypeMapIndex(lowercasePaths[pathIndex - 1].name),
                     ty: pathIndex === 0 ? null : lowercasePaths[pathIndex - 1].ty,
                     generics: [],
                 }];
             } else {
                 output = buildItemSearchTypeAll(
                     functionSearchType[OUTPUT_DATA],
-                    lowercasePaths,
-                    typeNameIdMap
+                    lowercasePaths
                 );
             }
         } else {
@@ -2233,6 +2479,12 @@ function initSearch(rawSearchIndex) {
         let currentIndex = 0;
         let id = 0;
 
+        // Initialize type map indexes for primitive list types
+        // that can be searched using `[]` syntax.
+        typeNameIdOfArray = buildTypeMapIndex("array");
+        typeNameIdOfSlice = buildTypeMapIndex("slice");
+        typeNameIdOfArrayOrSlice = buildTypeMapIndex("[]");
+
         for (const crate in rawSearchIndex) {
             if (!hasOwnPropertyRustdoc(rawSearchIndex, crate)) {
                 continue;
@@ -2363,8 +2615,7 @@ function initSearch(rawSearchIndex) {
                     parent: itemParentIdxs[i] > 0 ? paths[itemParentIdxs[i] - 1] : undefined,
                     type: buildFunctionSearchType(
                         itemFunctionSearchTypes[i],
-                        lowercasePaths,
-                        typeNameIdMap
+                        lowercasePaths
                     ),
                     id: id,
                     normalizedName: word.indexOf("_") === -1 ? word : word.replace(/_/g, ""),
@@ -2566,13 +2817,8 @@ function initSearch(rawSearchIndex) {
     function updateCrate(ev) {
         if (ev.target.value === "all crates") {
             // If we don't remove it from the URL, it'll be picked up again by the search.
-            const params = searchState.getQueryStringParams();
             const query = searchState.input.value.trim();
-            if (!history.state && !params.search) {
-                history.pushState(null, "", buildUrl(query, null));
-            } else {
-                history.replaceState(null, "", buildUrl(query, null));
-            }
+            updateSearchHistory(buildUrl(query, null));
         }
         // In case you "cut" the entry from the search input, then change the crate filter
         // before paste back the previous search, you get the old search results without
diff --git a/src/librustdoc/html/static/js/source-script.js b/src/librustdoc/html/static/js/source-script.js
index d999f3b36..6eb991360 100644
--- a/src/librustdoc/html/static/js/source-script.js
+++ b/src/librustdoc/html/static/js/source-script.js
@@ -3,13 +3,13 @@
 
 // Local js definitions:
 /* global addClass, getCurrentValue, onEachLazy, removeClass, browserSupportsHistoryApi */
-/* global updateLocalStorage */
+/* global updateLocalStorage, getVar */
 
 "use strict";
 
 (function() {
 
-const rootPath = document.getElementById("rustdoc-vars").attributes["data-root-path"].value;
+const rootPath = getVar("root-path");
 
 const NAME_OFFSET = 0;
 const DIRS_OFFSET = 1;
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index 93979a944..71961f6f2 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -108,7 +108,7 @@ function getCurrentValue(name) {
 // Get a value from the rustdoc-vars div, which is used to convey data from
 // Rust to the JS. If there is no such element, return null.
 const getVar = (function getVar(name) {
-    const el = document.getElementById("rustdoc-vars");
+    const el = document.querySelector("head > meta[name='rustdoc-vars']");
     return el ? el.attributes["data-" + name].value : null;
 });
 
diff --git a/src/librustdoc/html/templates/item_info.html b/src/librustdoc/html/templates/item_info.html
index d2ea9bdae..9e65ae95e 100644
--- a/src/librustdoc/html/templates/item_info.html
+++ b/src/librustdoc/html/templates/item_info.html
@@ -1,5 +1,5 @@
 {% if !items.is_empty() %}
-    <span class="item-info"> {# #}
+    <span class="item-info">
         {% for item in items %}
             {{item|safe}} {# #}
         {% endfor %}
diff --git a/src/librustdoc/html/templates/item_union.html b/src/librustdoc/html/templates/item_union.html
index c21967005..f6d2fa348 100644
--- a/src/librustdoc/html/templates/item_union.html
+++ b/src/librustdoc/html/templates/item_union.html
@@ -1,17 +1,18 @@
 <pre class="rust item-decl"><code>
-    {{ self::item_template_render_attributes_in_pre(self.borrow()) | safe }}
+    {{ self.render_attributes_in_pre() | safe }}
     {{ self.render_union() | safe }}
 </code></pre>
-{{ self::item_template_document(self.borrow()) | safe }}
+{{ self.document() | safe }}
 {% if self.fields_iter().peek().is_some() %}
-    <h2 id="fields" class="fields small-section-header">
-        Fields<a href="#fields" class="anchor">§</a>
+    <h2 id="fields" class="fields small-section-header"> {# #}
+        Fields<a href="#fields" class="anchor">§</a> {# #}
     </h2>
     {% for (field, ty) in self.fields_iter() %}
         {% let name = field.name.expect("union field name") %}
-        <span id="structfield.{{ name }}" class="{{ ItemType::StructField }} small-section-header">
-            <a href="#structfield.{{ name }}" class="anchor field">§</a>
-            <code>{{ name }}: {{ self.print_ty(ty) | safe }}</code>
+        <span id="structfield.{{ name }}" {#+ #}
+            class="{{ ItemType::StructField +}} small-section-header"> {# #}
+            <a href="#structfield.{{ name }}" class="anchor field">§</a> {# #}
+            <code>{{ name }}: {{+ self.print_ty(ty) | safe }}</code> {# #}
         </span>
         {% if let Some(stability_class) = self.stability_field(field) %}
             <span class="stab {{ stability_class }}"></span>
@@ -19,5 +20,5 @@
         {{ self.document_field(field) | safe }}
     {% endfor %}
 {% endif %}
-{{ self::item_template_render_assoc_items(self.borrow()) | safe }}
-{{ self::item_template_document_type_layout(self.borrow()) | safe }}
+{{ self.render_assoc_items() | safe }}
+{{ self.document_type_layout() | safe }}
diff --git a/src/librustdoc/html/templates/page.html b/src/librustdoc/html/templates/page.html
index 9133f899a..d4ec9c34b 100644
--- a/src/librustdoc/html/templates/page.html
+++ b/src/librustdoc/html/templates/page.html
@@ -24,13 +24,14 @@
       {% endfor %}
     ></script> {# #}
     {% endif %}
-    <div id="rustdoc-vars" {#+ #}
+    <meta name="rustdoc-vars" {#+ #}
          data-root-path="{{page.root_path|safe}}" {#+ #}
          data-static-root-path="{{static_root_path|safe}}" {#+ #}
          data-current-crate="{{layout.krate}}" {#+ #}
          data-themes="{{themes|join(",") }}" {#+ #}
          data-resource-suffix="{{page.resource_suffix}}" {#+ #}
          data-rustdoc-version="{{rustdoc_version}}" {#+ #}
+         data-channel="{{rust_channel}}" {#+ #}
          data-search-js="{{files.search_js}}" {#+ #}
          data-settings-js="{{files.settings_js}}" {#+ #}
          data-settings-css="{{files.settings_css}}" {#+ #}
@@ -38,7 +39,6 @@
          data-theme-dark-css="{{files.theme_dark_css}}" {#+ #}
          data-theme-ayu-css="{{files.theme_ayu_css}}" {#+ #}
     > {# #}
-    </div> {# #}
     <script src="{{static_root_path|safe}}{{files.storage_js}}"></script> {# #}
     {% if page.css_class.contains("crate") %}
     <script defer src="{{page.root_path|safe}}crates{{page.resource_suffix}}.js"></script> {# #}
diff --git a/src/librustdoc/html/templates/print_item.html b/src/librustdoc/html/templates/print_item.html
index edabac9a0..68a295ae0 100644
--- a/src/librustdoc/html/templates/print_item.html
+++ b/src/librustdoc/html/templates/print_item.html
@@ -1,5 +1,5 @@
 <div class="main-heading"> {# #}
-    <h1> {# #}
+    <h1>
         {{typ}}
         {# The breadcrumbs of the item path, like std::string #}
         {% for component in path_components %}
@@ -12,7 +12,7 @@
                 alt="Copy item path"> {# #}
         </button> {# #}
     </h1> {# #}
-    <span class="out-of-band"> {# #}
+    <span class="out-of-band">
         {% if !stability_since_raw.is_empty() %}
         {{ stability_since_raw|safe +}} · {#+ #}
         {% endif %}