Fix existing clippy warnings

purl/src/lib.rs

@@ -152,7 +152,7 @@ impl PurlShape for String {
 /// Without type-specific functionality, it's possible to create PURLs that have
 /// incorrect capitalization or are missing a required namespace or required
 /// qualifiers.
-impl<'a> PurlShape for Cow<'a, str> {
+impl PurlShape for Cow<'_, str> {
     type Error = ParseError;
 
     fn package_type(&self) -> Cow<str> {

purl/src/parse.rs

@@ -322,7 +322,7 @@ mod de {
 
     struct PurlVisitor<T>(PhantomData<T>);
 
-    impl<'de, T> Visitor<'de> for PurlVisitor<T>
+    impl<T> Visitor<'_> for PurlVisitor<T>
     where
         T: FromStr + PurlShape,
         <T as PurlShape>::Error: fmt::Display + From<<T as FromStr>::Err>,

purl/src/qualifiers.rs

@@ -501,9 +501,9 @@ impl<'a> Iterator for Iter<'a> {
     }
 }
 
-impl<'a> ExactSizeIterator for Iter<'a> {}
+impl ExactSizeIterator for Iter<'_> {}
 
-impl<'a> DoubleEndedIterator for Iter<'a> {
+impl DoubleEndedIterator for Iter<'_> {
     fn next_back(&mut self) -> Option<Self::Item> {
         let (k, v) = self.0.next_back()?;
         Some((k, v.as_str()))
@@ -534,9 +534,9 @@ impl<'a> Iterator for IterMut<'a> {
     }
 }
 
-impl<'a> ExactSizeIterator for IterMut<'a> {}
+impl ExactSizeIterator for IterMut<'_> {}
 
-impl<'a> DoubleEndedIterator for IterMut<'a> {
+impl DoubleEndedIterator for IterMut<'_> {
     fn next_back(&mut self) -> Option<Self::Item> {
         let (k, v) = self.0.next_back()?;
         Some((k, v))

purl/src/qualifiers/well_known.rs

@@ -100,7 +100,7 @@ pub struct Checksum<'a> {
     algorithms: HashMap<SmallString, Cow<'a, str>>,
 }
 
-impl<'a> KnownQualifierKey for Checksum<'a> {
+impl KnownQualifierKey for Checksum<'_> {
     const KEY: &'static str = "checksum";
 }
 
@@ -154,7 +154,7 @@ impl<'a> TryFrom<Checksum<'a>> for SmallString {
     }
 }
 
-impl<'a> Checksum<'a> {
+impl Checksum<'_> {
     /// Get a reference to the hex bytes of a hash.
     ///
     /// The hash may not be valid hex bytes.
@@ -258,7 +258,7 @@ impl<'a> ChecksumValue<'a> {
     }
 }
 
-impl<'a> Deref for ChecksumValue<'a> {
+impl Deref for ChecksumValue<'_> {
     type Target = str;
 
     fn deref(&self) -> &Self::Target {