Merge rust-bitcoin/rust-secp256k1#776: fix: fix some clippy warnings

0f7e5ffa21fdbd6d69190585a3b061a99c2d41a4 fix: fix some clippy warnings (Dimitris Apostolou)

Pull request description:

ACKs for top commit:
  apoelstra:
    ACK 0f7e5ffa21fdbd6d69190585a3b061a99c2d41a4; successfully ran local tests

Tree-SHA512: b72ac3b9d6bb2fe96104640acf1335b639bcfd3fbefde8d66deae2c0924e25e3f6ae13055812d1cb5d2f807aaa9a600f94b9c1319ba21ff92e13874a64ab0a36

Author: william2332-limf

src/context.rs

@@ -100,9 +100,9 @@ mod private {
     use super::*;
     pub trait Sealed {}
 
-    impl<'buf> Sealed for AllPreallocated<'buf> {}
-    impl<'buf> Sealed for VerifyOnlyPreallocated<'buf> {}
-    impl<'buf> Sealed for SignOnlyPreallocated<'buf> {}
+    impl Sealed for AllPreallocated<'_> {}
+    impl Sealed for VerifyOnlyPreallocated<'_> {}
+    impl Sealed for SignOnlyPreallocated<'_> {}
 }
 
 #[cfg(feature = "alloc")]
@@ -274,13 +274,13 @@ mod alloc_only {
     }
 }
 
-impl<'buf> Signing for SignOnlyPreallocated<'buf> {}
-impl<'buf> Signing for AllPreallocated<'buf> {}
+impl Signing for SignOnlyPreallocated<'_> {}
+impl Signing for AllPreallocated<'_> {}
 
-impl<'buf> Verification for VerifyOnlyPreallocated<'buf> {}
-impl<'buf> Verification for AllPreallocated<'buf> {}
+impl Verification for VerifyOnlyPreallocated<'_> {}
+impl Verification for AllPreallocated<'_> {}
 
-unsafe impl<'buf> Context for SignOnlyPreallocated<'buf> {
+unsafe impl Context for SignOnlyPreallocated<'_> {
     const FLAGS: c_uint = ffi::SECP256K1_START_SIGN;
     const DESCRIPTION: &'static str = "signing only";
 
@@ -289,7 +289,7 @@ unsafe impl<'buf> Context for SignOnlyPreallocated<'buf> {
     }
 }
 
-unsafe impl<'buf> Context for VerifyOnlyPreallocated<'buf> {
+unsafe impl Context for VerifyOnlyPreallocated<'_> {
     const FLAGS: c_uint = ffi::SECP256K1_START_VERIFY;
     const DESCRIPTION: &'static str = "verification only";
 
@@ -298,7 +298,7 @@ unsafe impl<'buf> Context for VerifyOnlyPreallocated<'buf> {
     }
 }
 
-unsafe impl<'buf> Context for AllPreallocated<'buf> {
+unsafe impl Context for AllPreallocated<'_> {
     const FLAGS: c_uint = SignOnlyPreallocated::FLAGS | VerifyOnlyPreallocated::FLAGS;
     const DESCRIPTION: &'static str = "all capabilities";
 

src/key.rs

@@ -1517,7 +1517,7 @@ impl<'de> serde::Deserialize<'de> for Parity {
     fn deserialize<D: serde::Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
         struct Visitor;
 
-        impl<'de> serde::de::Visitor<'de> for Visitor {
+        impl serde::de::Visitor<'_> for Visitor {
             type Value = Parity;
 
             fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {

src/lib.rs

@@ -499,7 +499,7 @@ fn to_hex<'a>(src: &[u8], target: &'a mut [u8]) -> Result<&'a str, ()> {
     }
     let result = &target[..hex_len];
     debug_assert!(str::from_utf8(result).is_ok());
-    return unsafe { Ok(str::from_utf8_unchecked(result)) };
+    unsafe { Ok(str::from_utf8_unchecked(result)) }
 }
 
 #[cfg(feature = "rand")]

src/serde_util.rs

@@ -18,7 +18,7 @@ impl<T> FromStrVisitor<T> {
     }
 }
 
-impl<'de, T> de::Visitor<'de> for FromStrVisitor<T>
+impl<T> de::Visitor<'_> for FromStrVisitor<T>
 where
     T: FromStr,
     <T as FromStr>::Err: fmt::Display,
@@ -49,7 +49,7 @@ where
     }
 }
 
-impl<'de, F, T, Err> de::Visitor<'de> for BytesVisitor<F>
+impl<F, T, Err> de::Visitor<'_> for BytesVisitor<F>
 where
     F: FnOnce(&[u8]) -> Result<T, Err>,
     Err: fmt::Display,