style: Make clippy happy

examples/example_fixture.rs

@@ -15,7 +15,8 @@ fn run() -> Result<(), Box<dyn Error>> {
     let code = env::var("exit")
         .ok()
         .map(|v| v.parse::<i32>())
-        .map_or(Ok(None), |r| r.map(Some))?
+        .map(|r| r.map(Some))
+        .unwrap_or(Ok(None))?
         .unwrap_or(0);
     process::exit(code);
 }

src/assert.rs

@@ -485,7 +485,7 @@ impl Assert {
 impl fmt::Display for Assert {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let palette = crate::Palette::color();
-        for &(ref name, ref context) in &self.context {
+        for (name, context) in &self.context {
             writeln!(f, "{:#}=`{:#}`", palette.key(name), palette.value(context))?;
         }
         output_fmt(&self.output, f)
@@ -1069,8 +1069,9 @@ impl fmt::Display for AssertError {
             AssertReason::UnexpectedFailure { actual_code } => writeln!(
                 f,
                 "Unexpected failure.\ncode-{}\nstderr=```{}```",
-                actual_code.map_or("<interrupted>".to_owned(), |actual_code| actual_code
-                    .to_string()),
+                actual_code
+                    .map(|actual_code| actual_code.to_string())
+                    .unwrap_or_else(|| "<interrupted>".to_owned()),
                 DebugBytes::new(&self.assert.output.stderr),
             ),
             AssertReason::UnexpectedSuccess => {

src/bin/bin_fixture.rs

@@ -19,7 +19,8 @@ fn run() -> Result<(), Box<dyn Error>> {
     let code = env::var("exit")
         .ok()
         .map(|v| v.parse::<i32>())
-        .map_or(Ok(None), |r| r.map(Some))?
+        .map(|r| r.map(Some))
+        .unwrap_or(Ok(None))?
         .unwrap_or(0);
     process::exit(code);
 }

src/cargo.rs

@@ -202,7 +202,7 @@ pub fn cargo_bin<S: AsRef<str>>(name: S) -> path::PathBuf {
 
 fn cargo_bin_str(name: &str) -> path::PathBuf {
     let env_var = format!("CARGO_BIN_EXE_{}", name);
-    std::env::var_os(&env_var)
+    std::env::var_os(env_var)
         .map(|p| p.into())
         .unwrap_or_else(|| target_dir().join(format!("{}{}", name, env::consts::EXE_SUFFIX)))
 }