diff --git a/examples/nop-preprocessor.rs b/examples/nop-preprocessor.rs
index 38764207..486fd86d 100644
--- a/examples/nop-preprocessor.rs
+++ b/examples/nop-preprocessor.rs
@@ -37,7 +37,7 @@ fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> {
     let book_version = Version::parse(&ctx.mdbook_version)?;
     let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?;
 
-    if version_req.matches(&book_version) != true {
+    if !version_req.matches(&book_version) {
         eprintln!(
             "Warning: The {} plugin was built against version {} of mdbook, \
              but we're being called from version {}",
@@ -55,7 +55,7 @@ fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> {
 
 fn handle_supports(pre: &dyn Preprocessor, sub_args: &ArgMatches) -> ! {
     let renderer = sub_args.value_of("renderer").expect("Required argument");
-    let supported = pre.supports_renderer(&renderer);
+    let supported = pre.supports_renderer(renderer);
 
     // Signal whether the renderer is supported by exiting with 1 or 0.
     if supported {
diff --git a/src/book/book.rs b/src/book/book.rs
index b7d344b3..da2a0a3c 100644
--- a/src/book/book.rs
+++ b/src/book/book.rs
@@ -22,7 +22,7 @@ pub fn load_book<P: AsRef<Path>>(src_dir: P, cfg: &BuildConfig) -> Result<Book>
         .with_context(|| format!("Summary parsing failed for file={:?}", summary_md))?;
 
     if cfg.create_missing {
-        create_missing(&src_dir, &summary).with_context(|| "Unable to create missing chapters")?;
+        create_missing(src_dir, &summary).with_context(|| "Unable to create missing chapters")?;
     }
 
     load_book_from_disk(&summary, src_dir)
@@ -381,7 +381,7 @@ And here is some \
 
         root.nested_items.push(second.clone().into());
         root.nested_items.push(SummaryItem::Separator);
-        root.nested_items.push(second.clone().into());
+        root.nested_items.push(second.into());
 
         (root, temp_dir)
     }
@@ -454,7 +454,7 @@ And here is some \
             sub_items: vec![
                 BookItem::Chapter(nested.clone()),
                 BookItem::Separator,
-                BookItem::Chapter(nested.clone()),
+                BookItem::Chapter(nested),
             ],
         });
 
diff --git a/src/book/summary.rs b/src/book/summary.rs
index 822a7c76..981e1079 100644
--- a/src/book/summary.rs
+++ b/src/book/summary.rs
@@ -382,7 +382,7 @@ impl<'a> SummaryParser<'a> {
                 }
                 Some(ev @ Event::Start(Tag::List(..))) => {
                     self.back(ev);
-                    let mut bunch_of_items = self.parse_nested_numbered(&root_number)?;
+                    let mut bunch_of_items = self.parse_nested_numbered(root_number)?;
 
                     // if we've resumed after something like a rule the root sections
                     // will be numbered from 1. We need to manually go back and update
diff --git a/src/preprocess/cmd.rs b/src/preprocess/cmd.rs
index 44654ffe..c47fd5d2 100644
--- a/src/preprocess/cmd.rs
+++ b/src/preprocess/cmd.rs
@@ -49,7 +49,7 @@ impl CmdPreprocessor {
     fn write_input_to_child(&self, child: &mut Child, book: &Book, ctx: &PreprocessorContext) {
         let stdin = child.stdin.take().expect("Child has stdin");
 
-        if let Err(e) = self.write_input(stdin, &book, &ctx) {
+        if let Err(e) = self.write_input(stdin, book, ctx) {
             // Looks like the backend hung up before we could finish
             // sending it the render context. Log the error and keep going
             warn!("Error writing the RenderContext to the backend, {}", e);
diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index 02b7da46..52abea51 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -57,7 +57,7 @@ impl HtmlHandlebars {
         let fixed_content = utils::render_markdown_with_path(
             &ch.content,
             ctx.html_config.curly_quotes,
-            Some(&path),
+            Some(path),
         );
         if !ctx.is_index {
             // Add page break between chapters
@@ -178,7 +178,7 @@ impl HtmlHandlebars {
         let rendered =
             self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
         let output_file = get_404_output_file(&html_config.input_404);
-        utils::fs::write_file(&destination, output_file, rendered.as_bytes())?;
+        utils::fs::write_file(destination, output_file, rendered.as_bytes())?;
         debug!("Creating 404.html ✓");
         Ok(())
     }
@@ -223,10 +223,10 @@ impl HtmlHandlebars {
         }
         write_file(destination, "css/variables.css", &theme.variables_css)?;
         if let Some(contents) = &theme.favicon_png {
-            write_file(destination, "favicon.png", &contents)?;
+            write_file(destination, "favicon.png", contents)?;
         }
         if let Some(contents) = &theme.favicon_svg {
-            write_file(destination, "favicon.svg", &contents)?;
+            write_file(destination, "favicon.svg", contents)?;
         }
         write_file(destination, "highlight.css", &theme.highlight_css)?;
         write_file(destination, "tomorrow-night.css", &theme.tomorrow_night_css)?;
@@ -509,7 +509,7 @@ impl Renderer for HtmlHandlebars {
         debug!("Register handlebars helpers");
         self.register_hbs_helpers(&mut handlebars, &html_config);
 
-        let mut data = make_data(&ctx.root, &book, &ctx.config, &html_config, &theme)?;
+        let mut data = make_data(&ctx.root, book, &ctx.config, &html_config, &theme)?;
 
         // Print version
         let mut print_content = String::new();
@@ -552,14 +552,14 @@ impl Renderer for HtmlHandlebars {
             let rendered =
                 self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
 
-            utils::fs::write_file(&destination, "print.html", rendered.as_bytes())?;
+            utils::fs::write_file(destination, "print.html", rendered.as_bytes())?;
             debug!("Creating print.html ✓");
         }
 
         debug!("Copy static files");
-        self.copy_static_files(&destination, &theme, &html_config)
+        self.copy_static_files(destination, &theme, &html_config)
             .with_context(|| "Unable to copy across static files")?;
-        self.copy_additional_css_and_js(&html_config, &ctx.root, &destination)
+        self.copy_additional_css_and_js(&html_config, &ctx.root, destination)
             .with_context(|| "Unable to copy across additional CSS and JS")?;
 
         // Render search index
@@ -567,7 +567,7 @@ impl Renderer for HtmlHandlebars {
         {
             let search = html_config.search.unwrap_or_default();
             if search.enable {
-                super::search::create_files(&search, &destination, &book)?;
+                super::search::create_files(&search, destination, book)?;
             }
         }
 
@@ -575,7 +575,7 @@ impl Renderer for HtmlHandlebars {
             .context("Unable to emit redirects")?;
 
         // Copy all remaining files, avoid a recursive copy from/to the book build dir
-        utils::fs::copy_files_except_ext(&src_dir, &destination, true, Some(&build_dir), &["md"])?;
+        utils::fs::copy_files_except_ext(&src_dir, destination, true, Some(&build_dir), &["md"])?;
 
         Ok(())
     }
@@ -983,7 +983,7 @@ mod tests {
         ];
 
         for (src, should_be) in inputs {
-            let got = build_header_links(&src);
+            let got = build_header_links(src);
             assert_eq!(got, should_be);
         }
     }
diff --git a/src/renderer/html_handlebars/helpers/navigation.rs b/src/renderer/html_handlebars/helpers/navigation.rs
index 3ff99560..83bdadb3 100644
--- a/src/renderer/html_handlebars/helpers/navigation.rs
+++ b/src/renderer/html_handlebars/helpers/navigation.rs
@@ -91,7 +91,7 @@ fn find_chapter(
         match item.get("path") {
             Some(path) if !path.is_empty() => {
                 if let Some(previous) = previous {
-                    if let Some(item) = target.find(&base_path, &path, &item, &previous)? {
+                    if let Some(item) = target.find(&base_path, path, &item, &previous)? {
                         return Ok(Some(item));
                     }
                 }
diff --git a/src/renderer/html_handlebars/helpers/toc.rs b/src/renderer/html_handlebars/helpers/toc.rs
index bde5383e..a2ea501d 100644
--- a/src/renderer/html_handlebars/helpers/toc.rs
+++ b/src/renderer/html_handlebars/helpers/toc.rs
@@ -142,7 +142,7 @@ impl HelperDef for RenderToc {
                 // Section does not necessarily exist
                 if let Some(section) = item.get("section") {
                     out.write("<strong aria-hidden=\"true\">")?;
-                    out.write(&section)?;
+                    out.write(section)?;
                     out.write("</strong> ")?;
                 }
             }
diff --git a/src/renderer/html_handlebars/search.rs b/src/renderer/html_handlebars/search.rs
index e9da2196..97c65c18 100644
--- a/src/renderer/html_handlebars/search.rs
+++ b/src/renderer/html_handlebars/search.rs
@@ -17,10 +17,10 @@ pub fn create_files(search_config: &Search, destination: &Path, book: &Book) ->
     let mut doc_urls = Vec::with_capacity(book.sections.len());
 
     for item in book.iter() {
-        render_item(&mut index, &search_config, &mut doc_urls, item)?;
+        render_item(&mut index, search_config, &mut doc_urls, item)?;
     }
 
-    let index = write_to_json(index, &search_config, doc_urls)?;
+    let index = write_to_json(index, search_config, doc_urls)?;
     debug!("Writing search index ✓");
     if index.len() > 10_000_000 {
         warn!("searchindex.json is very large ({} bytes)", index.len());
@@ -134,7 +134,7 @@ fn render_item(
                 // in an HtmlBlock tag. We must collect consecutive Html events
                 // into a block ourselves.
                 while let Some(Event::Html(html)) = p.peek() {
-                    html_block.push_str(&html);
+                    html_block.push_str(html);
                     p.next();
                 }
 
diff --git a/src/utils/fs.rs b/src/utils/fs.rs
index 2d5ce8b7..a933d548 100644
--- a/src/utils/fs.rs
+++ b/src/utils/fs.rs
@@ -247,7 +247,7 @@ mod tests {
         }
 
         if let Err(e) =
-            copy_files_except_ext(&tmp.path(), &tmp.path().join("output"), true, None, &["md"])
+            copy_files_except_ext(tmp.path(), &tmp.path().join("output"), true, None, &["md"])
         {
             panic!("Error while executing the function:\n{:?}", e);
         }
diff --git a/tests/rendered_output.rs b/tests/rendered_output.rs
index c6f998d6..3eae6c3f 100644
--- a/tests/rendered_output.rs
+++ b/tests/rendered_output.rs
@@ -264,7 +264,7 @@ fn root_index_html() -> Result<Document> {
 fn check_second_toc_level() {
     let doc = root_index_html().unwrap();
     let mut should_be = Vec::from(TOC_SECOND_LEVEL);
-    should_be.sort();
+    should_be.sort_unstable();
 
     let pred = descendants!(
         Class("chapter"),
@@ -288,7 +288,7 @@ fn check_first_toc_level() {
     let mut should_be = Vec::from(TOC_TOP_LEVEL);
 
     should_be.extend(TOC_SECOND_LEVEL);
-    should_be.sort();
+    should_be.sort_unstable();
 
     let pred = descendants!(
         Class("chapter"),
@@ -535,7 +535,7 @@ fn redirects_are_emitted_correctly() {
         let mut redirect_file = md.build_dir_for("html");
         // append everything except the bits that make it absolute
         // (e.g. "/" or "C:\")
-        redirect_file.extend(remove_absolute_components(&original));
+        redirect_file.extend(remove_absolute_components(original));
         let contents = fs::read_to_string(&redirect_file).unwrap();
         assert!(contents.contains(redirect));
     }
@@ -552,7 +552,7 @@ fn edit_url_has_default_src_dir_edit_url() {
         edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"    
         "#;
 
-    write_file(&temp.path(), "book.toml", book_toml.as_bytes()).unwrap();
+    write_file(temp.path(), "book.toml", book_toml.as_bytes()).unwrap();
 
     let md = MDBook::load(temp.path()).unwrap();
     md.build().unwrap();
@@ -560,9 +560,7 @@ fn edit_url_has_default_src_dir_edit_url() {
     let index_html = temp.path().join("book").join("index.html");
     assert_contains_strings(
         index_html,
-        &vec![
-            r#"href="https://github.com/rust-lang/mdBook/edit/master/guide/src/README.md" title="Suggest an edit""#,
-        ],
+        &[r#"href="https://github.com/rust-lang/mdBook/edit/master/guide/src/README.md" title="Suggest an edit""#],
     );
 }
 
@@ -578,7 +576,7 @@ fn edit_url_has_configured_src_dir_edit_url() {
         edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"    
         "#;
 
-    write_file(&temp.path(), "book.toml", book_toml.as_bytes()).unwrap();
+    write_file(temp.path(), "book.toml", book_toml.as_bytes()).unwrap();
 
     let md = MDBook::load(temp.path()).unwrap();
     md.build().unwrap();
@@ -586,9 +584,7 @@ fn edit_url_has_configured_src_dir_edit_url() {
     let index_html = temp.path().join("book").join("index.html");
     assert_contains_strings(
         index_html,
-        &vec![
-            r#"href="https://github.com/rust-lang/mdBook/edit/master/guide/src2/README.md" title="Suggest an edit""#,
-        ],
+        &[r#"href="https://github.com/rust-lang/mdBook/edit/master/guide/src2/README.md" title="Suggest an edit""#],
     );
 }
 
@@ -611,7 +607,7 @@ mod search {
         let index = fs::read_to_string(index).unwrap();
         let index = index.trim_start_matches("Object.assign(window.search, ");
         let index = index.trim_end_matches(");");
-        serde_json::from_str(&index).unwrap()
+        serde_json::from_str(index).unwrap()
     }
 
     #[test]