src/tools/clippy/src/docs/derivable_impls.txt

   1 ### What it does
   2 Detects manual `std::default::Default` implementations that are identical to a derived implementation.
   3
   4 ### Why is this bad?
   5 It is less concise.
   6
   7 ### Example
   8 ```
   9 struct Foo {
  10     bar: bool
  11 }
  12
  13 impl Default for Foo {
  14     fn default() -> Self {
  15         Self {
  16             bar: false
  17         }
  18     }
  19 }
  20 ```
  21
  22 Use instead:
  23 ```
  24 #[derive(Default)]
  25 struct Foo {
  26     bar: bool
  27 }
  28 ```
  29
  30 ### Known problems
  31 Derive macros [sometimes use incorrect bounds](https://github.com/rust-lang/rust/issues/26925)
  32 in generic types and the user defined `impl` may be more generalized or
  33 specialized than what derive will produce. This lint can't detect the manual `impl`
  34 has exactly equal bounds, and therefore this lint is disabled for types with
  35 generic parameters.