Fix rustc & clippy lints

Co-authored-by: Sven <SirWindfield@users.noreply.github.com>

src/filter/mod.rs

@@ -52,7 +52,6 @@
 //!
 //!     fn flush(&self) {}
 //! }
-//! # fn main() {}
 //! ```
 //!
 //! [Enabling Logging]: ../index.html#enabling-logging
@@ -92,24 +91,18 @@ pub struct Filter {
 /// ## Example
 ///
 /// ```
-/// #[macro_use]
-/// extern crate log;
-/// extern crate env_logger;
-///
-/// use std::env;
-/// use std::io;
+/// # #[macro_use] extern crate log;
+/// # use std::env;
 /// use env_logger::filter::Builder;
 ///
-/// fn main() {
-///     let mut builder = Builder::new();
-///
-///     // Parse a logging filter from an environment variable.
-///     if let Ok(rust_log) = env::var("RUST_LOG") {
-///        builder.parse(&rust_log);
-///     }
+/// let mut builder = Builder::new();
 ///
-///     let filter = builder.build();
+/// // Parse a logging filter from an environment variable.
+/// if let Ok(rust_log) = env::var("RUST_LOG") {
+///     builder.parse(&rust_log);
 /// }
+///
+/// let filter = builder.build();
 /// ```
 ///
 /// [`Filter`]: struct.Filter.html
@@ -132,20 +125,15 @@ impl Filter {
     /// # Example
     ///
     /// ```rust
-    /// extern crate log;
-    /// extern crate env_logger;
-    ///
     /// use log::LevelFilter;
     /// use env_logger::filter::Builder;
     ///
-    /// fn main() {
-    ///     let mut builder = Builder::new();
-    ///     builder.filter(Some("module1"), LevelFilter::Info);
-    ///     builder.filter(Some("module2"), LevelFilter::Error);
+    /// let mut builder = Builder::new();
+    /// builder.filter(Some("module1"), LevelFilter::Info);
+    /// builder.filter(Some("module2"), LevelFilter::Error);
     ///
-    ///     let filter = builder.build();
-    ///     assert_eq!(filter.filter(), LevelFilter::Info);
-    /// }
+    /// let filter = builder.build();
+    /// assert_eq!(filter.filter(), LevelFilter::Info);
     /// ```
     pub fn filter(&self) -> LevelFilter {
         self.directives
@@ -310,7 +298,7 @@ fn parse_spec(spec: &str) -> (Vec<Directive>, Option<inner::Filter>) {
         );
         return (dirs, None);
     }
-    mods.map(|m| {
+    if let Some(m) = mods {
         for s in m.split(',') {
             if s.is_empty() {
                 continue;
@@ -352,7 +340,7 @@ fn parse_spec(spec: &str) -> (Vec<Directive>, Option<inner::Filter>) {
                 level: log_level,
             });
         }
-    });
+    }
 
     let filter = filter.and_then(|filter| match inner::Filter::new(filter) {
         Ok(re) => Some(re),

src/fmt/mod.rs

@@ -136,13 +136,14 @@ impl fmt::Debug for Formatter {
     }
 }
 
+pub(crate) type FormatFn = Box<dyn Fn(&mut Formatter, &Record) -> io::Result<()> + Sync + Send>;
+
 pub(crate) struct Builder {
     pub format_timestamp: Option<TimestampPrecision>,
     pub format_module_path: bool,
     pub format_level: bool,
     pub format_indent: Option<usize>,
-    #[allow(unknown_lints, bare_trait_objects)]
-    pub custom_format: Option<Box<Fn(&mut Formatter, &Record) -> io::Result<()> + Sync + Send>>,
+    pub custom_format: Option<FormatFn>,
     built: bool,
 }
 
@@ -165,8 +166,7 @@ impl Builder {
     /// If the `custom_format` is `Some`, then any `default_format` switches are ignored.
     /// If the `custom_format` is `None`, then a default format is returned.
     /// Any `default_format` switches set to `false` won't be written by the format.
-    #[allow(unknown_lints, bare_trait_objects)]
-    pub fn build(&mut self) -> Box<Fn(&mut Formatter, &Record) -> io::Result<()> + Sync + Send> {
+    pub fn build(&mut self) -> FormatFn {
         assert!(!self.built, "attempt to re-use consumed builder");
 
         let built = mem::replace(
@@ -230,6 +230,7 @@ impl<'a> DefaultFormat<'a> {
                 .style()
                 .set_color(Color::Black)
                 .set_intense(true)
+                .clone()
                 .into_value(text)
         }
         #[cfg(not(feature = "termcolor"))]

src/fmt/writer/termcolor/extern_impl.rs

@@ -370,9 +370,9 @@ impl Style {
     }
 
     /// Wrap a value in the style by taking ownership of it.
-    pub(crate) fn into_value<T>(&mut self, value: T) -> StyledValue<'static, T> {
+    pub(crate) fn into_value<T>(self, value: T) -> StyledValue<'static, T> {
         StyledValue {
-            style: Cow::Owned(self.clone()),
+            style: Cow::Owned(self),
             value,
         }
     }
@@ -451,6 +451,7 @@ impl_styled_value_fmt!(
 ///
 /// Hexadecimal numbers are written with a `0x` prefix.
 #[allow(missing_docs)]
+#[non_exhaustive]
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum Color {
     Black,
@@ -463,8 +464,6 @@ pub enum Color {
     White,
     Ansi256(u8),
     Rgb(u8, u8, u8),
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 impl Color {
@@ -480,7 +479,6 @@ impl Color {
             Color::White => Some(termcolor::Color::White),
             Color::Ansi256(value) => Some(termcolor::Color::Ansi256(value)),
             Color::Rgb(r, g, b) => Some(termcolor::Color::Rgb(r, g, b)),
-            _ => None,
         }
     }
 }

src/lib.rs

@@ -15,20 +15,16 @@
 //! ## Example
 //!
 //! ```
-//! #[macro_use] extern crate log;
+//! use log::{debug, error, log_enabled, info, Level};
 //!
-//! use log::Level;
+//! env_logger::init();
 //!
-//! fn main() {
-//!     env_logger::init();
+//! debug!("this is a debug {}", "message");
+//! error!("this is printed by default");
 //!
-//!     debug!("this is a debug {}", "message");
-//!     error!("this is printed by default");
-//!
-//!     if log_enabled!(Level::Info) {
-//!         let x = 3 * 4; // expensive computation
-//!         info!("the answer was: {}", x);
-//!     }
+//! if log_enabled!(Level::Info) {
+//!     let x = 3 * 4; // expensive computation
+//!     info!("the answer was: {}", x);
 //! }
 //! ```
 //!
@@ -146,7 +142,6 @@
 //!
 //! ```
 //! # #[macro_use] extern crate log;
-//! # fn main() {}
 //! #[cfg(test)]
 //! mod tests {
 //!     fn init() {
@@ -245,7 +240,6 @@
 #![cfg_attr(rustbuild, feature(staged_api, rustc_private))]
 #![cfg_attr(rustbuild, unstable(feature = "rustc_private", issue = "27812"))]
 #![deny(missing_debug_implementations, missing_docs, warnings)]
-#![allow(clippy::needless_doctest_main)]
 
 use std::{borrow::Cow, cell::RefCell, env, io};
 
@@ -258,7 +252,7 @@ pub use self::fmt::glob::*;
 
 use self::filter::Filter;
 use self::fmt::writer::{self, Writer};
-use self::fmt::Formatter;
+use self::fmt::{FormatFn, Formatter};
 
 /// The default name for the environment variable to read filters from.
 pub const DEFAULT_FILTER_ENV: &str = "RUST_LOG";
@@ -310,8 +304,7 @@ struct Var<'a> {
 pub struct Logger {
     writer: Writer,
     filter: Filter,
-    #[allow(unknown_lints, bare_trait_objects)]
-    format: Box<Fn(&mut Formatter, &Record) -> io::Result<()> + Sync + Send>,
+    format: FormatFn,
 }
 
 /// `Builder` acts as builder for initializing a `Logger`.
@@ -322,23 +315,20 @@ pub struct Logger {
 /// # Examples
 ///
 /// ```
-/// #[macro_use] extern crate log;
-///
-/// use std::env;
-/// use std::io::Write;
-/// use log::LevelFilter;
+/// # #[macro_use] extern crate log;
+/// # use std::io::Write;
 /// use env_logger::Builder;
+/// use log::LevelFilter;
 ///
-/// fn main() {
-///     let mut builder = Builder::from_default_env();
+/// let mut builder = Builder::from_default_env();
 ///
-///     builder.format(|buf, record| writeln!(buf, "{} - {}", record.level(), record.args()))
-///            .filter(None, LevelFilter::Info)
-///            .init();
+/// builder
+///     .format(|buf, record| writeln!(buf, "{} - {}", record.level(), record.args()))
+///     .filter(None, LevelFilter::Info)
+///     .init();
 ///
-///     error!("error message");
-///     info!("info message");
-/// }
+/// error!("error message");
+/// info!("info message");
 /// ```
 #[derive(Default)]
 pub struct Builder {
@@ -360,16 +350,15 @@ impl Builder {
     /// Create a new builder and configure filters and style:
     ///
     /// ```
-    /// # fn main() {
     /// use log::LevelFilter;
     /// use env_logger::{Builder, WriteStyle};
     ///
     /// let mut builder = Builder::new();
     ///
-    /// builder.filter(None, LevelFilter::Info)
-    ///        .write_style(WriteStyle::Always)
-    ///        .init();
-    /// # }
+    /// builder
+    ///     .filter(None, LevelFilter::Info)
+    ///     .write_style(WriteStyle::Always)
+    ///     .init();
     /// ```
     ///
     /// [`filter`]: #method.filter
@@ -612,14 +601,12 @@ impl Builder {
     /// Only include messages for info and above for logs in `path::to::module`:
     ///
     /// ```
-    /// # fn main() {
-    /// use log::LevelFilter;
     /// use env_logger::Builder;
+    /// use log::LevelFilter;
     ///
     /// let mut builder = Builder::new();
     ///
     /// builder.filter_module("path::to::module", LevelFilter::Info);
-    /// # }
     /// ```
     pub fn filter_module(&mut self, module: &str, level: LevelFilter) -> &mut Self {
         self.filter.filter_module(module, level);
@@ -633,14 +620,12 @@ impl Builder {
     /// Only include messages for info and above for logs in `path::to::module`:
     ///
     /// ```
-    /// # fn main() {
-    /// use log::LevelFilter;
     /// use env_logger::Builder;
+    /// use log::LevelFilter;
     ///
     /// let mut builder = Builder::new();
     ///
     /// builder.filter_level(LevelFilter::Info);
-    /// # }
     /// ```
     pub fn filter_level(&mut self, level: LevelFilter) -> &mut Self {
         self.filter.filter_level(level);
@@ -657,14 +642,12 @@ impl Builder {
     /// Only include messages for info and above for logs in `path::to::module`:
     ///
     /// ```
-    /// # fn main() {
-    /// use log::LevelFilter;
     /// use env_logger::Builder;
+    /// use log::LevelFilter;
     ///
     /// let mut builder = Builder::new();
     ///
     /// builder.filter(Some("path::to::module"), LevelFilter::Info);
-    /// # }
     /// ```
     pub fn filter(&mut self, module: Option<&str>, level: LevelFilter) -> &mut Self {
         self.filter.filter(module, level);
@@ -1125,7 +1108,6 @@ pub fn init() {
 /// and `MY_LOG_STYLE` for writing colors:
 ///
 /// ```
-/// # extern crate env_logger;
 /// use env_logger::{Builder, Env};
 ///
 /// # fn run() -> Result<(), Box<::std::error::Error>> {
@@ -1135,7 +1117,7 @@ pub fn init() {
 ///
 /// Ok(())
 /// # }
-/// # fn main() { run().unwrap(); }
+/// # run().unwrap();
 /// ```
 ///
 /// # Errors