pcre2: small polishing

crates/pcre2/src/error.rs

@@ -1,6 +1,3 @@
-use std::error;
-use std::fmt;
-
 /// An error that can occur in this crate.
 ///
 /// Generally, this error corresponds to problems building a regular
@@ -12,7 +9,7 @@ pub struct Error {
 }
 
 impl Error {
-    pub(crate) fn regex<E: error::Error>(err: E) -> Error {
+    pub(crate) fn regex<E: std::error::Error>(err: E) -> Error {
         Error { kind: ErrorKind::Regex(err.to_string()) }
     }
 
@@ -24,6 +21,7 @@ impl Error {
 
 /// The kind of an error that can occur.
 #[derive(Clone, Debug)]
+#[non_exhaustive]
 pub enum ErrorKind {
     /// An error that occurred as a result of parsing a regular expression.
     /// This can be a syntax error or an error that results from attempting to
@@ -31,29 +29,20 @@ pub enum ErrorKind {
     ///
     /// The string here is the underlying error converted to a string.
     Regex(String),
-    /// Hints that destructuring should not be exhaustive.
-    ///
-    /// This enum may grow additional variants, so this makes sure clients
-    /// don't count on exhaustive matching. (Otherwise, adding a new variant
-    /// could break existing code.)
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
-impl error::Error for Error {
+impl std::error::Error for Error {
     fn description(&self) -> &str {
         match self.kind {
             ErrorKind::Regex(_) => "regex error",
-            ErrorKind::__Nonexhaustive => unreachable!(),
         }
     }
 }
 
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self.kind {
             ErrorKind::Regex(ref s) => write!(f, "{}", s),
-            ErrorKind::__Nonexhaustive => unreachable!(),
         }
     }
 }