src/tools/clippy/src/docs/wrong_self_convention.txt

   1 ### What it does
   2 Checks for methods with certain name prefixes and which
   3 doesn't match how self is taken. The actual rules are:
   4
   5 |Prefix |Postfix     |`self` taken                   | `self` type  |
   6 |-------|------------|-------------------------------|--------------|
   7 |`as_`  | none       |`&self` or `&mut self`         | any          |
   8 |`from_`| none       | none                          | any          |
   9 |`into_`| none       |`self`                         | any          |
  10 |`is_`  | none       |`&mut self` or `&self` or none | any          |
  11 |`to_`  | `_mut`     |`&mut self`                    | any          |
  12 |`to_`  | not `_mut` |`self`                         | `Copy`       |
  13 |`to_`  | not `_mut` |`&self`                        | not `Copy`   |
  14
  15 Note: Clippy doesn't trigger methods with `to_` prefix in:
  16 - Traits definition.
  17 Clippy can not tell if a type that implements a trait is `Copy` or not.
  18 - Traits implementation, when `&self` is taken.
  19 The method signature is controlled by the trait and often `&self` is required for all types that implement the trait
  20 (see e.g. the `std::string::ToString` trait).
  21
  22 Clippy allows `Pin<&Self>` and `Pin<&mut Self>` if `&self` and `&mut self` is required.
  23
  24 Please find more info here:
  25 https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv
  26
  27 ### Why is this bad?
  28 Consistency breeds readability. If you follow the
  29 conventions, your users won't be surprised that they, e.g., need to supply a
  30 mutable reference to a `as_..` function.
  31
  32 ### Example
  33 ```
  34 impl X {
  35     fn as_str(self) -> &'static str {
  36         // ..
  37     }
  38 }
  39 ```