Ignore needless_lifetimes clippy lint

    warning: the following explicit lifetimes could be elided: 'a
        --> src/de.rs:2169:11
         |
    2169 | impl<'de, 'a, R> MapKey<'a, R>
         |           ^^            ^^
         |
         = 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
         |
    2169 - impl<'de, 'a, R> MapKey<'a, R>
    2169 + impl<'de, R> MapKey<'_, R>
         |

    warning: the following explicit lifetimes could be elided: 'a
        --> src/de.rs:2176:11
         |
    2176 | impl<'de, 'a, R> de::Deserializer<'de> for MapKey<'a, R>
         |           ^^                                      ^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
         |
    2176 - impl<'de, 'a, R> de::Deserializer<'de> for MapKey<'a, R>
    2176 + impl<'de, R> de::Deserializer<'de> for MapKey<'_, R>
         |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/error.rs:467:6
        |
    467 | impl<'a> Display for JsonUnexpected<'a> {
        |      ^^                             ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    467 - impl<'a> Display for JsonUnexpected<'a> {
    467 + impl Display for JsonUnexpected<'_> {
        |

    warning: the following explicit lifetimes could be elided: 'a
      --> src/ser.rs:31:6
       |
    31 | impl<'a, W> Serializer<W, PrettyFormatter<'a>>
       |      ^^                                   ^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
       |
    31 - impl<'a, W> Serializer<W, PrettyFormatter<'a>>
    31 + impl<W> Serializer<W, PrettyFormatter<'_>>
       |

    warning: the following explicit lifetimes could be elided: 'ser
       --> src/ser.rs:420:14
        |
    420 |         impl<'ser, W, F> Write for Adapter<'ser, W, F>
        |              ^^^^                          ^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    420 -         impl<'ser, W, F> Write for Adapter<'ser, W, F>
    420 +         impl<W, F> Write for Adapter<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:480:6
        |
    480 | impl<'a, W, F> ser::SerializeSeq for Compound<'a, W, F>
        |      ^^                                       ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    480 - impl<'a, W, F> ser::SerializeSeq for Compound<'a, W, F>
    480 + impl<W, F> ser::SerializeSeq for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:527:6
        |
    527 | impl<'a, W, F> ser::SerializeTuple for Compound<'a, W, F>
        |      ^^                                         ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    527 - impl<'a, W, F> ser::SerializeTuple for Compound<'a, W, F>
    527 + impl<W, F> ser::SerializeTuple for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:549:6
        |
    549 | impl<'a, W, F> ser::SerializeTupleStruct for Compound<'a, W, F>
        |      ^^                                               ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    549 - impl<'a, W, F> ser::SerializeTupleStruct for Compound<'a, W, F>
    549 + impl<W, F> ser::SerializeTupleStruct for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:571:6
        |
    571 | impl<'a, W, F> ser::SerializeTupleVariant for Compound<'a, W, F>
        |      ^^                                                ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    571 - impl<'a, W, F> ser::SerializeTupleVariant for Compound<'a, W, F>
    571 + impl<W, F> ser::SerializeTupleVariant for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:609:6
        |
    609 | impl<'a, W, F> ser::SerializeMap for Compound<'a, W, F>
        |      ^^                                       ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    609 - impl<'a, W, F> ser::SerializeMap for Compound<'a, W, F>
    609 + impl<W, F> ser::SerializeMap for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:681:6
        |
    681 | impl<'a, W, F> ser::SerializeStruct for Compound<'a, W, F>
        |      ^^                                          ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    681 - impl<'a, W, F> ser::SerializeStruct for Compound<'a, W, F>
    681 + impl<W, F> ser::SerializeStruct for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:727:6
        |
    727 | impl<'a, W, F> ser::SerializeStructVariant for Compound<'a, W, F>
        |      ^^                                                 ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    727 - impl<'a, W, F> ser::SerializeStructVariant for Compound<'a, W, F>
    727 + impl<W, F> ser::SerializeStructVariant for Compound<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/ser.rs:793:6
        |
    793 | impl<'a, W, F> ser::Serializer for MapKeySerializer<'a, W, F>
        |      ^^                                             ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    793 - impl<'a, W, F> ser::Serializer for MapKeySerializer<'a, W, F>
    793 + impl<W, F> ser::Serializer for MapKeySerializer<'_, W, F>
        |

    warning: the following explicit lifetimes could be elided: 'a
        --> src/ser.rs:1157:6
         |
    1157 | impl<'a, W: io::Write, F: Formatter> ser::Serializer for NumberStrEmitter<'a, W, F> {
         |      ^^                                                                   ^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
         |
    1157 - impl<'a, W: io::Write, F: Formatter> ser::Serializer for NumberStrEmitter<'a, W, F> {
    1157 + impl<W: io::Write, F: Formatter> ser::Serializer for NumberStrEmitter<'_, W, F> {
         |

    warning: the following explicit lifetimes could be elided: 'a
        --> src/ser.rs:1334:6
         |
    1334 | impl<'a, W: io::Write, F: Formatter> ser::Serializer for RawValueStrEmitter<'a, W, F> {
         |      ^^                                                                     ^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
         |
    1334 - impl<'a, W: io::Write, F: Formatter> ser::Serializer for RawValueStrEmitter<'a, W, F> {
    1334 + impl<W: io::Write, F: Formatter> ser::Serializer for RawValueStrEmitter<'_, W, F> {
         |

    warning: the following explicit lifetimes could be elided: 'a
        --> src/ser.rs:1951:6
         |
    1951 | impl<'a> Default for PrettyFormatter<'a> {
         |      ^^                              ^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
         |
    1951 - impl<'a> Default for PrettyFormatter<'a> {
    1951 + impl Default for PrettyFormatter<'_> {
         |

    warning: the following explicit lifetimes could be elided: 'a
        --> src/ser.rs:1957:6
         |
    1957 | impl<'a> Formatter for PrettyFormatter<'a> {
         |      ^^                                ^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
         |
    1957 - impl<'a> Formatter for PrettyFormatter<'a> {
    1957 + impl Formatter for PrettyFormatter<'_> {
         |

    warning: the following explicit lifetimes could be elided: 'a, 'b
       --> src/value/mod.rs:227:14
        |
    227 |         impl<'a, 'b> io::Write for WriterFormatter<'a, 'b> {
        |              ^^  ^^                                ^^  ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    227 -         impl<'a, 'b> io::Write for WriterFormatter<'a, 'b> {
    227 +         impl io::Write for WriterFormatter<'_, '_> {
        |

    warning: the following explicit lifetimes could be elided: 'de
       --> src/value/de.rs:479:6
        |
    479 | impl<'de> IntoDeserializer<'de, Error> for Value {
        |      ^^^                   ^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    479 - impl<'de> IntoDeserializer<'de, Error> for Value {
    479 + impl IntoDeserializer<'_, Error> for Value {
        |

    warning: the following explicit lifetimes could be elided: 'de
        --> src/value/de.rs:1266:6
         |
    1266 | impl<'de> Visitor<'de> for KeyClassifier {
         |      ^^^          ^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
         |
    1266 - impl<'de> Visitor<'de> for KeyClassifier {
    1266 + impl Visitor<'_> for KeyClassifier {
         |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/value/index.rs:146:6
        |
    146 | impl<'a> Display for Type<'a> {
        |      ^^                   ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    146 - impl<'a> Display for Type<'a> {
    146 + impl Display for Type<'_> {
        |

        Checking toml v0.8.19
    warning: the following explicit lifetimes could be elided: 'de
       --> src/number.rs:460:14
        |
    460 |         impl<'de> de::Visitor<'de> for FieldVisitor {
        |              ^^^              ^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    460 -         impl<'de> de::Visitor<'de> for FieldVisitor {
    460 +         impl de::Visitor<'_> for FieldVisitor {
        |

    warning: the following explicit lifetimes could be elided: 'de
       --> src/number.rs:497:14
        |
    497 |         impl<'de> de::Visitor<'de> for Visitor {
        |              ^^^              ^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    497 -         impl<'de> de::Visitor<'de> for Visitor {
    497 +         impl de::Visitor<'_> for Visitor {
        |

    warning: the following explicit lifetimes could be elided: 'b, 'c
       --> src/read.rs:132:6
        |
    132 | impl<'b, 'c, T> Deref for Reference<'b, 'c, T>
        |      ^^  ^^                         ^^  ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    132 - impl<'b, 'c, T> Deref for Reference<'b, 'c, T>
    132 + impl<T> Deref for Reference<'_, '_, T>
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/read.rs:535:6
        |
    535 | impl<'a> private::Sealed for SliceRead<'a> {}
        |      ^^                                ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    535 - impl<'a> private::Sealed for SliceRead<'a> {}
    535 + impl private::Sealed for SliceRead<'_> {}
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/read.rs:673:6
        |
    673 | impl<'a> private::Sealed for StrRead<'a> {}
        |      ^^                              ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    673 - impl<'a> private::Sealed for StrRead<'a> {}
    673 + impl private::Sealed for StrRead<'_> {}
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/read.rs:827:6
        |
    827 | impl<'a> Fused for SliceRead<'a> {}
        |      ^^                      ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    827 - impl<'a> Fused for SliceRead<'a> {}
    827 + impl Fused for SliceRead<'_> {}
        |

    warning: the following explicit lifetimes could be elided: 'a
       --> src/read.rs:828:6
        |
    828 | impl<'a> Fused for StrRead<'a> {}
        |      ^^                    ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    828 - impl<'a> Fused for StrRead<'a> {}
    828 + impl Fused for StrRead<'_> {}
        |

    warning: the following explicit lifetimes could be elided: 'de
       --> src/raw.rs:374:14
        |
    374 |         impl<'de> Visitor<'de> for FieldVisitor {
        |              ^^^          ^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    374 -         impl<'de> Visitor<'de> for FieldVisitor {
    374 +         impl Visitor<'_> for FieldVisitor {
        |

    warning: the following explicit lifetimes could be elided: 'de
       --> src/raw.rs:439:6
        |
    439 | impl<'de> Visitor<'de> for BoxedFromString {
        |      ^^^          ^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
    help: elide the lifetimes
        |
    439 - impl<'de> Visitor<'de> for BoxedFromString {
    439 + impl Visitor<'_> for BoxedFromString {
        |

    warning: the following explicit lifetimes could be elided: 'de
      --> tests/regression/issue845.rs:12:6
       |
    12 | impl<'de, T> serde::de::Visitor<'de> for NumberVisitor<T>
       |      ^^^                        ^^^
       |
       = 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
       |
    12 - impl<'de, T> serde::de::Visitor<'de> for NumberVisitor<T>
    12 + impl<T> serde::de::Visitor<'_> for NumberVisitor<T>
       |

src/lib.rs

@@ -314,6 +314,7 @@
     clippy::match_single_binding,
     clippy::needless_doctest_main,
     clippy::needless_late_init,
+    clippy::needless_lifetimes,
     clippy::return_self_not_must_use,
     clippy::transmute_ptr_to_ptr,
     clippy::unconditional_recursion, // https://github.com/rust-lang/rust-clippy/issues/12133

tests/regression.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::needless_lifetimes)]
+
 mod regression {
     automod::dir!("tests/regression");
 }