clippy fixes

Author: matthiaskrgr

Diff for: src/bin/main.rs

@@ -26,7 +26,7 @@ fn main() {
     let exit_code = match execute(&opts) {
         Ok(code) => code,
         Err(e) => {
-            eprintln!("{}", e.to_string());
+            eprintln!("{}", e);
             1
         }
     };

Diff for: src/expr.rs

@@ -2003,9 +2003,7 @@ fn choose_rhs<R: Rewrite>(
     has_rhs_comment: bool,
 ) -> Option<String> {
     match orig_rhs {
-        Some(ref new_str) if new_str.is_empty() => {
-            return Some(String::new());
-        }
+        Some(ref new_str) if new_str.is_empty() => Some(String::new()),
         Some(ref new_str)
             if !new_str.contains('\n') && unicode_str_width(new_str) <= shape.width =>
         {

Diff for: src/formatting.rs

@@ -76,7 +76,7 @@ fn should_skip_module<T: FormatHandler>(
         return true;
     }
 
-    if !input_is_stdin && context.ignore_file(&path) {
+    if !input_is_stdin && context.ignore_file(path) {
         return true;
     }
 

Diff for: src/items.rs

@@ -1535,15 +1535,15 @@ pub(crate) fn rewrite_type_alias<'a, 'b>(
     // https://rustc-dev-guide.rust-lang.org/opaque-types-type-alias-impl-trait.html
     // https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/items.md#type-aliases
     match (visitor_kind, &op_ty) {
-        (Item(_) | AssocTraitItem(_) | ForeignItem(_), Some(ref op_bounds)) => {
+        (Item(_) | AssocTraitItem(_) | ForeignItem(_), Some(op_bounds)) => {
             let op = OpaqueType { bounds: op_bounds };
             rewrite_ty(rw_info, Some(bounds), Some(&op), vis)
         }
         (Item(_) | AssocTraitItem(_) | ForeignItem(_), None) => {
             rewrite_ty(rw_info, Some(bounds), ty_opt, vis)
         }
         (AssocImplItem(_), _) => {
-            let result = if let Some(ref op_bounds) = op_ty {
+            let result = if let Some(op_bounds) = op_ty {
                 let op = OpaqueType { bounds: op_bounds };
                 rewrite_ty(rw_info, Some(bounds), Some(&op), &DEFAULT_VISIBILITY)
             } else {
@@ -3124,7 +3124,7 @@ impl Rewrite for ast::ForeignItem {
                     let inner_attrs = inner_attributes(&self.attrs);
                     let fn_ctxt = visit::FnCtxt::Foreign;
                     visitor.visit_fn(
-                        visit::FnKind::Fn(fn_ctxt, self.ident, &sig, &self.vis, Some(body)),
+                        visit::FnKind::Fn(fn_ctxt, self.ident, sig, &self.vis, Some(body)),
                         generics,
                         &sig.decl,
                         self.span,
@@ -3137,7 +3137,7 @@ impl Rewrite for ast::ForeignItem {
                         context,
                         shape.indent,
                         self.ident,
-                        &FnSig::from_method_sig(&sig, generics, &self.vis),
+                        &FnSig::from_method_sig(sig, generics, &self.vis),
                         span,
                         FnBraceStyle::None,
                     )
@@ -3166,7 +3166,7 @@ impl Rewrite for ast::ForeignItem {
                 .map(|s| s + ";")
             }
             ast::ForeignItemKind::TyAlias(ref ty_alias) => {
-                let (kind, span) = (&ItemVisitorKind::ForeignItem(&self), self.span);
+                let (kind, span) = (&ItemVisitorKind::ForeignItem(self), self.span);
                 rewrite_type_alias(ty_alias, context, shape.indent, kind, span)
             }
             ast::ForeignItemKind::MacCall(ref mac) => {

Diff for: src/lists.rs

@@ -448,10 +448,8 @@ where
                     true
                 } else if starts_with_newline(comment) {
                     false
-                } else if comment.trim().contains('\n') || comment.trim().len() > width {
-                    true
                 } else {
-                    false
+                    comment.trim().contains('\n') || comment.trim().len() > width
                 };
 
                 rewrite_comment(

Diff for: src/visitor.rs

@@ -552,7 +552,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
                             _ => visit::FnCtxt::Foreign,
                         };
                         self.visit_fn(
-                            visit::FnKind::Fn(fn_ctxt, item.ident, &sig, &item.vis, Some(body)),
+                            visit::FnKind::Fn(fn_ctxt, item.ident, sig, &item.vis, Some(body)),
                             generics,
                             &sig.decl,
                             item.span,
@@ -562,14 +562,14 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
                     } else {
                         let indent = self.block_indent;
                         let rewrite = self.rewrite_required_fn(
-                            indent, item.ident, &sig, &item.vis, generics, item.span,
+                            indent, item.ident, sig, &item.vis, generics, item.span,
                         );
                         self.push_rewrite(item.span, rewrite);
                     }
                 }
                 ast::ItemKind::TyAlias(ref ty_alias) => {
                     use ItemVisitorKind::Item;
-                    self.visit_ty_alias_kind(ty_alias, &Item(&item), item.span);
+                    self.visit_ty_alias_kind(ty_alias, &Item(item), item.span);
                 }
                 ast::ItemKind::GlobalAsm(..) => {
                     let snippet = Some(self.snippet(item.span).to_owned());
@@ -619,17 +619,17 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         skip_out_of_file_lines_range_visitor!(self, ai.span);
 
         if self.visit_attrs(&ai.attrs, ast::AttrStyle::Outer) {
-            self.push_skipped_with_span(&ai.attrs.as_slice(), skip_span, skip_span);
+            self.push_skipped_with_span(ai.attrs.as_slice(), skip_span, skip_span);
             return;
         }
 
         // TODO(calebcartwright): consider enabling box_patterns feature gate
         match (&ai.kind, visitor_kind) {
             (ast::AssocItemKind::Const(..), AssocTraitItem(_)) => {
-                self.visit_static(&StaticParts::from_trait_item(&ai))
+                self.visit_static(&StaticParts::from_trait_item(ai))
             }
             (ast::AssocItemKind::Const(..), AssocImplItem(_)) => {
-                self.visit_static(&StaticParts::from_impl_item(&ai))
+                self.visit_static(&StaticParts::from_impl_item(ai))
             }
             (ast::AssocItemKind::Fn(ref fn_kind), _) => {
                 let ast::Fn {