fix new clippy and rustc warnings

There are only a few of these, and the lifetime ones are a compiler warning
rather than a clippy warning (meaning that they will cause failures in my
local CI) so fix them here.

Author: apoelstra

Cargo.toml

@@ -18,3 +18,7 @@ alloc = []
 
 [target.'cfg(mutate)'.dev-dependencies]
 mutagen = { git = "https://github.com/llogiq/mutagen" }
+
+[lints.rust]
+unexpected_cfgs = { level = "deny", check-cfg = ['cfg(bench)', 'cfg(kani)', 'cfg(mutate)'] }
+

src/primitives/decode.rs

@@ -134,7 +134,7 @@ impl<'s> UncheckedHrpstring<'s> {
 
         let ret = UncheckedHrpstring {
             hrp: Hrp::parse(hrp)?,
-            data_part_ascii: rest[1..].as_bytes(), // Skip the separator.
+            data_part_ascii: &rest.as_bytes()[1..], // Skip the separator.
             hrpstring_length: s.len(),
         };
 
@@ -442,7 +442,7 @@ impl<'s> CheckedHrpstring<'s> {
     ///
     /// Converts the ASCII bytes representing field elements to the respective field elements.
     #[inline]
-    pub fn fe32_iter<I: Iterator<Item = u8>>(&self) -> AsciiToFe32Iter {
+    pub fn fe32_iter<I: Iterator<Item = u8>>(&self) -> AsciiToFe32Iter<'_> {
         AsciiToFe32Iter { iter: self.ascii.iter().copied() }
     }
 
@@ -451,7 +451,7 @@ impl<'s> CheckedHrpstring<'s> {
     /// Converts the ASCII bytes representing field elements to the respective field elements, then
     /// converts the stream of field elements to a stream of bytes.
     #[inline]
-    pub fn byte_iter(&self) -> ByteIter {
+    pub fn byte_iter(&self) -> ByteIter<'_> {
         ByteIter { iter: AsciiToFe32Iter { iter: self.ascii.iter().copied() }.fes_to_bytes() }
     }
 
@@ -661,7 +661,7 @@ impl<'s> SegwitHrpstring<'s> {
     ///
     /// Use `self.witness_version()` to get the witness version.
     #[inline]
-    pub fn byte_iter(&self) -> ByteIter {
+    pub fn byte_iter(&self) -> ByteIter<'_> {
         ByteIter { iter: AsciiToFe32Iter { iter: self.ascii.iter().copied() }.fes_to_bytes() }
     }
 }

src/primitives/hrp.rs

@@ -163,24 +163,24 @@ impl Hrp {
     /// If an uppercase HRP was parsed during object construction then this iterator will yield
     /// uppercase ASCII `char`s. For lowercase bytes see [`Self::lowercase_byte_iter`]
     #[inline]
-    pub fn byte_iter(&self) -> ByteIter { ByteIter { iter: self.buf[..self.size].iter() } }
+    pub fn byte_iter(&self) -> ByteIter<'_> { ByteIter { iter: self.buf[..self.size].iter() } }
 
     /// Creates a character iterator over the ASCII characters of this HRP.
     ///
     /// If an uppercase HRP was parsed during object construction then this iterator will yield
     /// uppercase ASCII `char`s. For lowercase bytes see [`Self::lowercase_char_iter`].
     #[inline]
-    pub fn char_iter(&self) -> CharIter { CharIter { iter: self.byte_iter() } }
+    pub fn char_iter(&self) -> CharIter<'_> { CharIter { iter: self.byte_iter() } }
 
     /// Creates a lowercase iterator over the byte values (ASCII characters) of this HRP.
     #[inline]
-    pub fn lowercase_byte_iter(&self) -> LowercaseByteIter {
+    pub fn lowercase_byte_iter(&self) -> LowercaseByteIter<'_> {
         LowercaseByteIter { iter: self.byte_iter() }
     }
 
     /// Creates a lowercase character iterator over the ASCII characters of this HRP.
     #[inline]
-    pub fn lowercase_char_iter(&self) -> LowercaseCharIter {
+    pub fn lowercase_char_iter(&self) -> LowercaseCharIter<'_> {
         LowercaseCharIter { iter: self.lowercase_byte_iter() }
     }
 

src/primitives/iter.rs

@@ -61,7 +61,9 @@ pub trait Fe32IterExt: Sized + Iterator<Item = Fe32> {
 
     /// Adapts the Fe32 iterator to encode the field elements into a bech32 address.
     #[inline]
-    fn with_checksum<Ck: Checksum>(self, hrp: &Hrp) -> Encoder<Self, Ck> { Encoder::new(self, hrp) }
+    fn with_checksum<Ck: Checksum>(self, hrp: &Hrp) -> Encoder<'_, Self, Ck> {
+        Encoder::new(self, hrp)
+    }
 }
 
 impl<I> Fe32IterExt for I where I: Iterator<Item = Fe32> {}