Resolve needless_lifetimes clippy lints

    warning: the following explicit lifetimes could be elided: 'a
       --> src/de.rs:138:11
        |
    138 | impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
        |           ^^                             ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
        = note: `-W clippy::needless-lifetimes` implied by `-W clippy::all`
        = help: to override `-W clippy::all` add `#[allow(clippy::needless_lifetimes)]`
    help: elide the lifetimes
        |
    138 - impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
    138 + impl<'de> de::Deserializer<'de> for &mut Deserializer<'de> {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/de.rs:516:11
        |
    516 | impl<'de, 'a> SeqAccess<'de> for CommaSeparated<'a, 'de> {
        |           ^^                                    ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
        = note: `-W clippy::needless-lifetimes` implied by `-W clippy::all`
        = help: to override `-W clippy::all` add `#[allow(clippy::needless_lifetimes)]`
    help: elide the lifetimes
        |
    516 - impl<'de, 'a> SeqAccess<'de> for CommaSeparated<'a, 'de> {
    516 + impl<'de> SeqAccess<'de> for CommaSeparated<'_, 'de> {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/de.rs:539:11
        |
    539 | impl<'de, 'a> MapAccess<'de> for CommaSeparated<'a, 'de> {
        |           ^^                                    ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    539 - impl<'de, 'a> MapAccess<'de> for CommaSeparated<'a, 'de> {
    539 + impl<'de> MapAccess<'de> for CommaSeparated<'_, 'de> {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/de.rs:589:11
        |
    589 | impl<'de, 'a> EnumAccess<'de> for Enum<'a, 'de> {
        |           ^^                           ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    589 - impl<'de, 'a> EnumAccess<'de> for Enum<'a, 'de> {
    589 + impl<'de> EnumAccess<'de> for Enum<'_, 'de> {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/de.rs:612:11
        |
    612 | impl<'de, 'a> VariantAccess<'de> for Enum<'a, 'de> {
        |           ^^                              ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    612 - impl<'de, 'a> VariantAccess<'de> for Enum<'a, 'de> {
    612 + impl<'de> VariantAccess<'de> for Enum<'_, 'de> {
        |

    warning: the following explicit lifetimes could be elided: 'a
      --> src/ser.rs:33:6
       |
    33 | impl<'a> ser::Serializer for &'a mut Serializer {
       |      ^^                       ^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
       |
    33 - impl<'a> ser::Serializer for &'a mut Serializer {
    33 + impl ser::Serializer for &mut Serializer {
       |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:311:6
        |
    311 | impl<'a> ser::SerializeSeq for &'a mut Serializer {
        |      ^^                         ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    311 - impl<'a> ser::SerializeSeq for &'a mut Serializer {
    311 + impl ser::SerializeSeq for &mut Serializer {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:336:6
        |
    336 | impl<'a> ser::SerializeTuple for &'a mut Serializer {
        |      ^^                           ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    336 - impl<'a> ser::SerializeTuple for &'a mut Serializer {
    336 + impl ser::SerializeTuple for &mut Serializer {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:357:6
        |
    357 | impl<'a> ser::SerializeTupleStruct for &'a mut Serializer {
        |      ^^                                 ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    357 - impl<'a> ser::SerializeTupleStruct for &'a mut Serializer {
    357 + impl ser::SerializeTupleStruct for &mut Serializer {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:386:6
        |
    386 | impl<'a> ser::SerializeTupleVariant for &'a mut Serializer {
        |      ^^                                  ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    386 - impl<'a> ser::SerializeTupleVariant for &'a mut Serializer {
    386 + impl ser::SerializeTupleVariant for &mut Serializer {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:414:6
        |
    414 | impl<'a> ser::SerializeMap for &'a mut Serializer {
        |      ^^                         ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    414 - impl<'a> ser::SerializeMap for &'a mut Serializer {
    414 + impl ser::SerializeMap for &mut Serializer {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:455:6
        |
    455 | impl<'a> ser::SerializeStruct for &'a mut Serializer {
        |      ^^                            ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    455 - impl<'a> ser::SerializeStruct for &'a mut Serializer {
    455 + impl ser::SerializeStruct for &mut Serializer {
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:479:6
        |
    479 | impl<'a> ser::SerializeStructVariant for &'a mut Serializer {
        |      ^^                                   ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    479 - impl<'a> ser::SerializeStructVariant for &'a mut Serializer {
    479 + impl ser::SerializeStructVariant for &mut Serializer {
        |

Author: dtolnay

src/de.rs

@@ -135,7 +135,7 @@ impl<'de> Deserializer<'de> {
     }
 }
 
-impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
+impl<'de> de::Deserializer<'de> for &mut Deserializer<'de> {
     type Error = Error;
 
     // Look at the input data to decide what Serde data model type to
@@ -513,7 +513,7 @@ impl<'a, 'de> CommaSeparated<'a, 'de> {
 
 // `SeqAccess` is provided to the `Visitor` to give it the ability to iterate
 // through elements of the sequence.
-impl<'de, 'a> SeqAccess<'de> for CommaSeparated<'a, 'de> {
+impl<'de> SeqAccess<'de> for CommaSeparated<'_, 'de> {
     type Error = Error;
 
     fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
@@ -536,7 +536,7 @@ impl<'de, 'a> SeqAccess<'de> for CommaSeparated<'a, 'de> {
 
 // `MapAccess` is provided to the `Visitor` to give it the ability to iterate
 // through entries of the map.
-impl<'de, 'a> MapAccess<'de> for CommaSeparated<'a, 'de> {
+impl<'de> MapAccess<'de> for CommaSeparated<'_, 'de> {
     type Error = Error;
 
     fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
@@ -586,7 +586,7 @@ impl<'a, 'de> Enum<'a, 'de> {
 //
 // Note that all enum deserialization methods in Serde refer exclusively to the
 // "externally tagged" enum representation.
-impl<'de, 'a> EnumAccess<'de> for Enum<'a, 'de> {
+impl<'de> EnumAccess<'de> for Enum<'_, 'de> {
     type Error = Error;
     type Variant = Self;
 
@@ -609,7 +609,7 @@ impl<'de, 'a> EnumAccess<'de> for Enum<'a, 'de> {
 
 // `VariantAccess` is provided to the `Visitor` to give it the ability to see
 // the content of the single variant that it decided to deserialize.
-impl<'de, 'a> VariantAccess<'de> for Enum<'a, 'de> {
+impl<'de> VariantAccess<'de> for Enum<'_, 'de> {
     type Error = Error;
 
     // If the `Visitor` expected this variant to be a unit variant, the input

src/ser.rs

@@ -30,7 +30,7 @@ where
     Ok(serializer.output)
 }
 
-impl<'a> ser::Serializer for &'a mut Serializer {
+impl ser::Serializer for &mut Serializer {
     // The output type produced by this `Serializer` during successful
     // serialization. Most serializers that produce text or binary output should
     // set `Ok = ()` and serialize into an `io::Write` or buffer contained
@@ -308,7 +308,7 @@ impl<'a> ser::Serializer for &'a mut Serializer {
 //
 // This impl is SerializeSeq so these methods are called after `serialize_seq`
 // is called on the Serializer.
-impl<'a> ser::SerializeSeq for &'a mut Serializer {
+impl ser::SerializeSeq for &mut Serializer {
     // Must match the `Ok` type of the serializer.
     type Ok = ();
     // Must match the `Error` type of the serializer.
@@ -333,7 +333,7 @@ impl<'a> ser::SerializeSeq for &'a mut Serializer {
 }
 
 // Same thing but for tuples.
-impl<'a> ser::SerializeTuple for &'a mut Serializer {
+impl ser::SerializeTuple for &mut Serializer {
     type Ok = ();
     type Error = Error;
 
@@ -354,7 +354,7 @@ impl<'a> ser::SerializeTuple for &'a mut Serializer {
 }
 
 // Same thing but for tuple structs.
-impl<'a> ser::SerializeTupleStruct for &'a mut Serializer {
+impl ser::SerializeTupleStruct for &mut Serializer {
     type Ok = ();
     type Error = Error;
 
@@ -383,7 +383,7 @@ impl<'a> ser::SerializeTupleStruct for &'a mut Serializer {
 //
 // So the `end` method in this impl is responsible for closing both the `]` and
 // the `}`.
-impl<'a> ser::SerializeTupleVariant for &'a mut Serializer {
+impl ser::SerializeTupleVariant for &mut Serializer {
     type Ok = ();
     type Error = Error;
 
@@ -411,7 +411,7 @@ impl<'a> ser::SerializeTupleVariant for &'a mut Serializer {
 // `serialize_entry` method allows serializers to optimize for the case where
 // key and value are both available simultaneously. In JSON it doesn't make a
 // difference so the default behavior for `serialize_entry` is fine.
-impl<'a> ser::SerializeMap for &'a mut Serializer {
+impl ser::SerializeMap for &mut Serializer {
     type Ok = ();
     type Error = Error;
 
@@ -452,7 +452,7 @@ impl<'a> ser::SerializeMap for &'a mut Serializer {
 
 // Structs are like maps in which the keys are constrained to be compile-time
 // constant strings.
-impl<'a> ser::SerializeStruct for &'a mut Serializer {
+impl ser::SerializeStruct for &mut Serializer {
     type Ok = ();
     type Error = Error;
 
@@ -476,7 +476,7 @@ impl<'a> ser::SerializeStruct for &'a mut Serializer {
 
 // Similar to `SerializeTupleVariant`, here the `end` method is responsible for
 // closing both of the curly braces opened by `serialize_struct_variant`.
-impl<'a> ser::SerializeStructVariant for &'a mut Serializer {
+impl ser::SerializeStructVariant for &mut Serializer {
     type Ok = ();
     type Error = Error;