chore: drop derive-new dependency (#3917)

Author: lnicola

Cargo.lock

@@ -45,7 +45,6 @@ diff = "0.1"
 log = "0.4"
 env_logger = "0.6"
 getopts = "0.2"
-derive-new = "0.5"
 cargo_metadata = "0.8"
 failure = "0.1.3"
 bytecount = "0.6"

Cargo.toml

@@ -2,12 +2,18 @@ use crate::comment::CommentStyle;
 use std::fmt::{self, Display};
 
 /// Formats a string as a doc comment using the given [`CommentStyle`].
-#[derive(new)]
 pub(super) struct DocCommentFormatter<'a> {
     literal: &'a str,
     style: CommentStyle<'a>,
 }
 
+impl<'a> DocCommentFormatter<'a> {
+    /// Constructs a new `DocCommentFormatter`.
+    pub(super) fn new(literal: &'a str, style: CommentStyle<'a>) -> Self {
+        Self { literal, style }
+    }
+}
+
 impl Display for DocCommentFormatter<'_> {
     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
         let opener = self.style.opener().trim_end();

src/attr/doc_comment.rs

@@ -118,8 +118,7 @@ fn format_project<T: FormatHandler>(
     Ok(context.report)
 }
 
-// Used for formatting files.
-#[derive(new)]
+/// Used for formatting files.
 struct FormatContext<'a, T: FormatHandler> {
     krate: &'a ast::Crate,
     report: FormatReport,
@@ -129,6 +128,23 @@ struct FormatContext<'a, T: FormatHandler> {
 }
 
 impl<'a, T: FormatHandler + 'a> FormatContext<'a, T> {
+    /// Constructs a new FormatContext.
+    fn new(
+        krate: &'a ast::Crate,
+        report: FormatReport,
+        parse_session: ParseSess,
+        config: &'a Config,
+        handler: &'a mut T,
+    ) -> Self {
+        Self {
+            krate,
+            report,
+            parse_session,
+            config,
+            handler,
+        }
+    }
+
     fn ignore_file(&self, path: &FileName) -> bool {
         self.parse_session.ignore_file(path)
     }

src/formatting.rs

@@ -1,8 +1,6 @@
 #![deny(rust_2018_idioms)]
 #![warn(unreachable_pub)]
 
-#[macro_use]
-extern crate derive_new;
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]

src/lib.rs

@@ -1220,14 +1220,18 @@ fn macro_style(mac: &ast::Mac, context: &RewriteContext<'_>) -> DelimToken {
     }
 }
 
-// A very simple parser that just parses a macros 2.0 definition into its branches.
-// Currently we do not attempt to parse any further than that.
-#[derive(new)]
+/// A very simple parser that just parses a macros 2.0 definition into its branches.
+/// Currently we do not attempt to parse any further than that.
 struct MacroParser {
     toks: Cursor,
 }
 
 impl MacroParser {
+    /// Constructs a new `MacroParser`.
+    fn new(toks: Cursor) -> Self {
+        Self { toks }
+    }
+
     // (`(` ... `)` `=>` `{` ... `}`)*
     fn parse(&mut self) -> Option<Macro> {
         let mut branches = vec![];

src/macros.rs

@@ -9,14 +9,23 @@ use crate::utils::{
 };
 
 /// Sigils that decorate a binop pair.
-#[derive(new, Clone, Copy)]
+#[derive(Clone, Copy)]
 pub(crate) struct PairParts<'a> {
     prefix: &'a str,
     infix: &'a str,
     suffix: &'a str,
 }
 
 impl<'a> PairParts<'a> {
+    /// Constructs a new `PairParts`.
+    pub(crate) fn new(prefix: &'a str, infix: &'a str, suffix: &'a str) -> Self {
+        Self {
+            prefix,
+            infix,
+            suffix,
+        }
+    }
+
     pub(crate) fn infix(infix: &'a str) -> PairParts<'a> {
         PairParts {
             prefix: "",