Fix some clippy warnings

src/env.rs

@@ -10,7 +10,7 @@ use serde::de::IntoDeserializer;
 /// Semantically private, only public as it's used in the API of the `internal`
 /// module. Gets converted into `ErrorKind::EnvDeserialization` before reaching
 /// the real public API.
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq)]
 pub struct DeError(pub(crate) String);
 
 impl std::error::Error for DeError {}

src/template.rs

@@ -222,7 +222,7 @@ fn format_impl(out: &mut impl Formatter, meta: &Meta, options: &FormatOptions) {
         emitted_anything = true;
 
         let comments = if options.comments { field.doc } else { &[] };
-        out.start_nested(&field.name, comments);
+        out.start_nested(field.name, comments);
         format_impl(out, meta, options);
         out.end_nested();
     }

src/toml.rs

@@ -180,7 +180,7 @@ impl fmt::Display for PrintExpr<'_> {
 
                     match entry.key {
                         MapKey::Str(s) if is_valid_bare_key(s) => f.write_str(s)?,
-                        _ => PrintExpr(&entry.key.clone().into()).fmt(f)?,
+                        _ => PrintExpr(&entry.key.into()).fmt(f)?,
                     }
                     f.write_str(" = ")?;
                     PrintExpr(&entry.value).fmt(f)?;

src/yaml.rs

@@ -197,7 +197,7 @@ impl fmt::Display for PrintExpr<'_> {
                     if i != 0 {
                         f.write_str(", ")?;
                     }
-                    PrintExpr(&entry.key.clone().into()).fmt(f)?;
+                    PrintExpr(&entry.key.into()).fmt(f)?;
                     f.write_str(": ")?;
                     PrintExpr(&entry.value).fmt(f)?;
                 }