# Configuring Rustfmt
-Rustfmt is designed to be very configurable. You can create a TOML file called `rustfmt.toml` or `.rustfmt.toml`, place it in the project or any other parent directory and it will apply the options in that file.
+Rustfmt is designed to be very configurable. You can create a TOML file called `rustfmt.toml` or `.rustfmt.toml`, place it in the project or any other parent directory and it will apply the options in that file. If none of these directories contain such a file, both your home directory and a directory called `rustfmt` in your [global config directory](https://docs.rs/dirs/1.0.4/dirs/fn.config_dir.html) (e.g. `.config/rustfmt/`) are checked as well.
A possible content of `rustfmt.toml` or `.rustfmt.toml` might look like this:
Below you find a detailed visual guide on all the supported configuration options of rustfmt:
+## `array_width`
-## `indent_style`
+Maximum width of an array literal before falling back to vertical formatting.
-Indent on expressions or items.
+- **Default value**: `60`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
-- **Default value**: `"Block"`
-- **Possible values**: `"Block"`, `"Visual"`
-- **Stable**: No
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `array_width` will take precedence.
-### Array
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-#### `"Block"` (default):
+## `attr_fn_like_width`
+
+Maximum width of the args of a function-like attributes before falling back to vertical formatting.
+
+- **Default value**: `70`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `attr_fn_like_width` will take precedence.
+
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
+
+## `binop_separator`
+
+Where to put a binary operator when a binary expression goes multiline.
+
+- **Default value**: `"Front"`
+- **Possible values**: `"Front"`, `"Back"`
+- **Stable**: No (tracking issue: #3368)
+
+#### `"Front"` (default):
```rust
fn main() {
- let lorem = vec![
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit",
- ];
+ let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo
+ || barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+
+ let sum = 123456789012345678901234567890
+ + 123456789012345678901234567890
+ + 123456789012345678901234567890;
+
+ let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ ..bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
}
```
-#### `"Visual"`:
+#### `"Back"`:
```rust
fn main() {
- let lorem = vec!["ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit"];
+ let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo ||
+ barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+
+ let sum = 123456789012345678901234567890 +
+ 123456789012345678901234567890 +
+ 123456789012345678901234567890;
+
+ let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
}
```
-### Control flow
+## `blank_lines_lower_bound`
-#### `"Block"` (default):
+Minimum number of blank lines which must be put between items. If two items have fewer blank lines between
+them, additional blank lines are inserted.
+
+- **Default value**: `0`
+- **Possible values**: *unsigned integer*
+- **Stable**: No (tracking issue: #3382)
+
+### Example
+Original Code (rustfmt will not change it with the default value of `0`):
```rust
-fn main() {
- if lorem_ipsum
- && dolor_sit
- && amet_consectetur
- && lorem_sit
- && dolor_consectetur
- && amet_ipsum
- && lorem_consectetur
- {
- // ...
- }
+#![rustfmt::skip]
+
+fn foo() {
+ println!("a");
+}
+fn bar() {
+ println!("b");
+ println!("c");
}
```
-#### `"Visual"`:
-
+#### `1`
```rust
-fn main() {
- if lorem_ipsum
- && dolor_sit
- && amet_consectetur
- && lorem_sit
- && dolor_consectetur
- && amet_ipsum
- && lorem_consectetur
- {
- // ...
- }
+fn foo() {
+
+ println!("a");
+}
+
+fn bar() {
+
+ println!("b");
+
+ println!("c");
}
```
-See also: [`control_brace_style`](#control_brace_style).
-### Function arguments
+## `blank_lines_upper_bound`
-#### `"Block"` (default):
+Maximum number of blank lines which can be put between items. If more than this number of consecutive empty
+lines are found, they are trimmed down to match this integer.
-```rust
-fn lorem() {}
+- **Default value**: `1`
+- **Possible values**: any non-negative integer
+- **Stable**: No (tracking issue: #3381)
-fn lorem(ipsum: usize) {}
+### Example
+Original Code:
-fn lorem(
- ipsum: usize,
- dolor: usize,
- sit: usize,
- amet: usize,
- consectetur: usize,
- adipiscing: usize,
- elit: usize,
-) {
- // body
+```rust
+#![rustfmt::skip]
+
+fn foo() {
+ println!("a");
}
-```
-#### `"Visual"`:
-```rust
-fn lorem() {}
-fn lorem(ipsum: usize) {}
+fn bar() {
+ println!("b");
-fn lorem(ipsum: usize,
- dolor: usize,
- sit: usize,
- amet: usize,
- consectetur: usize,
- adipiscing: usize,
- elit: usize) {
- // body
+
+ println!("c");
}
```
-### Function calls
+#### `1` (default):
+```rust
+fn foo() {
+ println!("a");
+}
-#### `"Block"` (default):
+fn bar() {
+ println!("b");
-```rust
-fn main() {
- lorem(
- "lorem",
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit",
- );
+ println!("c");
}
```
-#### `"Visual"`:
-
+#### `2`:
```rust
-fn main() {
- lorem("lorem",
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- "elit");
+fn foo() {
+ println!("a");
}
-```
-### Generics
-#### `"Block"` (default):
+fn bar() {
+ println!("b");
-```rust
-fn lorem<
- Ipsum: Eq = usize,
- Dolor: Eq = usize,
- Sit: Eq = usize,
- Amet: Eq = usize,
- Adipiscing: Eq = usize,
- Consectetur: Eq = usize,
- Elit: Eq = usize,
->(
- ipsum: Ipsum,
- dolor: Dolor,
- sit: Sit,
- amet: Amet,
- adipiscing: Adipiscing,
- consectetur: Consectetur,
- elit: Elit,
-) -> T {
- // body
+
+ println!("c");
}
```
-#### `"Visual"`:
+See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
-```rust
-fn lorem<Ipsum: Eq = usize,
- Dolor: Eq = usize,
- Sit: Eq = usize,
- Amet: Eq = usize,
- Adipiscing: Eq = usize,
- Consectetur: Eq = usize,
- Elit: Eq = usize>(
- ipsum: Ipsum,
- dolor: Dolor,
- sit: Sit,
- amet: Amet,
- adipiscing: Adipiscing,
- consectetur: Consectetur,
- elit: Elit)
- -> T {
- // body
-}
-```
+## `brace_style`
-#### Struct
+Brace style for items
-#### `"Block"` (default):
+- **Default value**: `"SameLineWhere"`
+- **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
+- **Stable**: No (tracking issue: #3376)
+
+### Functions
+
+#### `"SameLineWhere"` (default):
```rust
-fn main() {
- let lorem = Lorem {
- ipsum: dolor,
- sit: amet,
- };
+fn lorem() {
+ // body
}
-```
-#### `"Visual"`:
+fn lorem(ipsum: usize) {
+ // body
+}
-```rust
-fn main() {
- let lorem = Lorem { ipsum: dolor,
- sit: amet, };
+fn lorem<T>(ipsum: T)
+where
+ T: Add + Sub + Mul + Div,
+{
+ // body
}
```
-See also: [`struct_lit_single_line`](#struct_lit_single_line), [`indent_style`](#indent_style).
+#### `"AlwaysNextLine"`:
-### Where predicates
+```rust
+fn lorem()
+{
+ // body
+}
-#### `"Block"` (default):
+fn lorem(ipsum: usize)
+{
+ // body
+}
-```rust
-fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
+fn lorem<T>(ipsum: T)
where
- Ipsum: Eq,
- Dolor: Eq,
- Sit: Eq,
- Amet: Eq,
+ T: Add + Sub + Mul + Div,
{
// body
}
```
-#### `"Visual"`:
+#### `"PreferSameLine"`:
```rust
-fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
- where Ipsum: Eq,
- Dolor: Eq,
- Sit: Eq,
- Amet: Eq
-{
+fn lorem() {
// body
}
-```
-## `use_small_heuristics`
+fn lorem(ipsum: usize) {
+ // body
+}
-Whether to use different formatting for items and expressions if they satisfy a heuristic notion of 'small'.
+fn lorem<T>(ipsum: T)
+where
+ T: Add + Sub + Mul + Div, {
+ // body
+}
+```
-- **Default value**: `Default`
-- **Possible values**: `Default`, `Off`, `Max`
-- **Stable**: Yes
+### Structs and enums
-#### `Default` (default):
+#### `"SameLineWhere"` (default):
```rust
-enum Lorem {
- Ipsum,
- Dolor(bool),
- Sit { amet: Consectetur, adipiscing: Elit },
+struct Lorem {
+ ipsum: bool,
}
-fn main() {
- lorem(
- "lorem",
- "ipsum",
- "dolor",
- "sit",
- "amet",
- "consectetur",
- "adipiscing",
- );
-
- let lorem = Lorem {
- ipsum: dolor,
- sit: amet,
- };
- let lorem = Lorem { ipsum: dolor };
-
- let lorem = if ipsum { dolor } else { sit };
+struct Dolor<T>
+where
+ T: Eq,
+{
+ sit: T,
}
```
-#### `Off`:
+#### `"AlwaysNextLine"`:
```rust
-enum Lorem {
- Ipsum,
- Dolor(bool),
- Sit {
- amet: Consectetur,
- adipiscing: Elit,
- },
+struct Lorem
+{
+ ipsum: bool,
}
-fn main() {
- lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-
- let lorem = Lorem {
- ipsum: dolor,
- sit: amet,
- };
-
- let lorem = if ipsum {
- dolor
- } else {
- sit
- };
+struct Dolor<T>
+where
+ T: Eq,
+{
+ sit: T,
}
```
-#### `Max`:
+#### `"PreferSameLine"`:
```rust
-enum Lorem {
- Ipsum,
- Dolor(bool),
- Sit { amet: Consectetur, adipiscing: Elit },
+struct Lorem {
+ ipsum: bool,
}
-fn main() {
- lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-
- let lorem = Lorem { ipsum: dolor, sit: amet };
-
- let lorem = if ipsum { dolor } else { sit };
+struct Dolor<T>
+where
+ T: Eq, {
+ sit: T,
}
```
-## `binop_separator`
-
-Where to put a binary operator when a binary expression goes multiline.
-
-- **Default value**: `"Front"`
-- **Possible values**: `"Front"`, `"Back"`
-- **Stable**: No
-
-#### `"Front"` (default):
+## `chain_width`
-```rust
-fn main() {
- let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo
- || barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+Maximum width of a chain to fit on one line.
- let sum = 123456789012345678901234567890
- + 123456789012345678901234567890
- + 123456789012345678901234567890;
+- **Default value**: `60`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
- let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
- ..bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
-}
-```
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `chain_width` will take precedence.
-#### `"Back"`:
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-```rust
-fn main() {
- let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo ||
- barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
+## `color`
- let sum = 123456789012345678901234567890 +
- 123456789012345678901234567890 +
- 123456789012345678901234567890;
+Whether to use colored output or not.
- let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..
- bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
-}
-```
+- **Default value**: `"Auto"`
+- **Possible values**: "Auto", "Always", "Never"
+- **Stable**: No (tracking issue: #3385)
## `combine_control_expr`
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3369)
#### `true` (default):
- **Default value**: `80`
- **Possible values**: any positive integer
-- **Stable**: No
+- **Stable**: No (tracking issue: #3349)
**Note:** A value of `0` results in [`wrap_comments`](#wrap_comments) being applied regardless of a line's width.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3384)
#### `false` (default):
- **Default value**: `"AlwaysSameLine"`
- **Possible values**: `"AlwaysNextLine"`, `"AlwaysSameLine"`, `"ClosingNextLine"`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3377)
#### `"AlwaysSameLine"` (default):
```rust
-fn main() {
- if lorem {
- println!("ipsum!");
- } else {
- println!("dolor!");
- }
+fn main() {
+ if lorem {
+ println!("ipsum!");
+ } else {
+ println!("dolor!");
+ }
+}
+```
+
+#### `"AlwaysNextLine"`:
+
+```rust
+fn main() {
+ if lorem
+ {
+ println!("ipsum!");
+ }
+ else
+ {
+ println!("dolor!");
+ }
+}
+```
+
+#### `"ClosingNextLine"`:
+
+```rust
+fn main() {
+ if lorem {
+ println!("ipsum!");
+ }
+ else {
+ println!("dolor!");
+ }
+}
+```
+
+## `disable_all_formatting`
+
+Don't reformat anything
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3388)
+
+## `edition`
+
+Specifies which edition is used by the parser.
+
+- **Default value**: `"2015"`
+- **Possible values**: `"2015"`, `"2018"`, `"2021"`
+- **Stable**: Yes
+
+Rustfmt is able to pick up the edition used by reading the `Cargo.toml` file if executed
+through the Cargo's formatting tool `cargo fmt`. Otherwise, the edition needs to be specified
+in your config file:
+
+```toml
+edition = "2018"
+```
+
+## `empty_item_single_line`
+
+Put empty-body functions and impls on a single line
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3356)
+
+#### `true` (default):
+
+```rust
+fn lorem() {}
+
+impl Lorem {}
+```
+
+#### `false`:
+
+```rust
+fn lorem() {
+}
+
+impl Lorem {
+}
+```
+
+See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
+
+
+## `enum_discrim_align_threshold`
+
+The maximum length of enum variant having discriminant, that gets vertically aligned with others.
+Variants without discriminants would be ignored for the purpose of alignment.
+
+Note that this is not how much whitespace is inserted, but instead the longest variant name that
+doesn't get ignored when aligning.
+
+- **Default value** : 0
+- **Possible values**: any positive integer
+- **Stable**: No (tracking issue: #3372)
+
+#### `0` (default):
+
+```rust
+enum Bar {
+ A = 0,
+ Bb = 1,
+ RandomLongVariantGoesHere = 10,
+ Ccc = 71,
}
-```
-
-#### `"AlwaysNextLine"`:
-```rust
-fn main() {
- if lorem
- {
- println!("ipsum!");
- }
- else
- {
- println!("dolor!");
- }
+enum Bar {
+ VeryLongVariantNameHereA = 0,
+ VeryLongVariantNameHereBb = 1,
+ VeryLongVariantNameHereCcc = 2,
}
```
-#### `"ClosingNextLine"`:
+#### `20`:
```rust
-fn main() {
- if lorem {
- println!("ipsum!");
- }
- else {
- println!("dolor!");
- }
+enum Foo {
+ A = 0,
+ Bb = 1,
+ RandomLongVariantGoesHere = 10,
+ Ccc = 2,
}
-```
-
-## `disable_all_formatting`
-Don't reformat anything
+enum Bar {
+ VeryLongVariantNameHereA = 0,
+ VeryLongVariantNameHereBb = 1,
+ VeryLongVariantNameHereCcc = 2,
+}
+```
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
## `error_on_line_overflow`
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3391)
See also [`max_width`](#max_width).
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3392)
-## `fn_args_density`
+## `fn_args_layout`
-Argument density in functions
+Control the layout of arguments in a function
- **Default value**: `"Tall"`
- **Possible values**: `"Compressed"`, `"Tall"`, `"Vertical"`
-- **Stable**: No
+- **Stable**: Yes
#### `"Tall"` (default):
}
```
+## `fn_call_width`
+
+Maximum width of the args of a function call before falling back to vertical formatting.
+
+- **Default value**: `60`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `fn_call_width` will take precedence.
+
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
+
+## `fn_single_line`
+
+Put single-expression functions on a single line
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3358)
+
+#### `false` (default):
+
+```rust
+fn lorem() -> usize {
+ 42
+}
+
+fn lorem() -> usize {
+ let ipsum = 42;
+ ipsum
+}
+```
+
+#### `true`:
+
+```rust
+fn lorem() -> usize { 42 }
+
+fn lorem() -> usize {
+ let ipsum = 42;
+ ipsum
+}
+```
+
+See also [`control_brace_style`](#control_brace_style).
+
+
+## `force_explicit_abi`
+
+Always print the abi for extern items
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
+
+**Note:** Non-"C" ABIs are always printed. If `false` then "C" is removed.
+
+#### `true` (default):
+
+```rust
+extern "C" {
+ pub static lorem: c_int;
+}
+```
+
+#### `false`:
+
+```rust
+extern {
+ pub static lorem: c_int;
+}
+```
+
+## `force_multiline_blocks`
+
+Force multiline closure and match arm bodies to be wrapped in a block
+
+- **Default value**: `false`
+- **Possible values**: `false`, `true`
+- **Stable**: No (tracking issue: #3374)
+
+#### `false` (default):
+
+```rust
+fn main() {
+ result.and_then(|maybe_value| match maybe_value {
+ None => foo(),
+ Some(value) => bar(),
+ });
+
+ match lorem {
+ None => |ipsum| {
+ println!("Hello World");
+ },
+ Some(dolor) => foo(),
+ }
+}
+```
+
+#### `true`:
+
+```rust
+fn main() {
+ result.and_then(|maybe_value| {
+ match maybe_value {
+ None => foo(),
+ Some(value) => bar(),
+ }
+ });
+
+ match lorem {
+ None => {
+ |ipsum| {
+ println!("Hello World");
+ }
+ }
+ Some(dolor) => foo(),
+ }
+}
+```
+
+
+## `format_code_in_doc_comments`
+
+Format code snippet included in doc comments.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3348)
+
+#### `false` (default):
+
+```rust
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```rust
+/// let five=5;
+///
+/// assert_eq!(
+/// 6,
+/// add_one(5)
+/// );
+/// # fn add_one(x: i32) -> i32 {
+/// # x + 1
+/// # }
+/// ```
+fn add_one(x: i32) -> i32 {
+ x + 1
+}
+```
+
+#### `true`
+
+```rust
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```rust
+/// let five = 5;
+///
+/// assert_eq!(6, add_one(5));
+/// # fn add_one(x: i32) -> i32 {
+/// # x + 1
+/// # }
+/// ```
+fn add_one(x: i32) -> i32 {
+ x + 1
+}
+```
+
+## `format_macro_matchers`
+
+Format the metavariable matching patterns in macros.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3354)
+
+#### `false` (default):
+
+```rust
+macro_rules! foo {
+ ($a: ident : $b: ty) => {
+ $a(42): $b;
+ };
+ ($a: ident $b: ident $c: ident) => {
+ $a = $b + $c;
+ };
+}
+```
+
+#### `true`:
+
+```rust
+macro_rules! foo {
+ ($a:ident : $b:ty) => {
+ $a(42): $b;
+ };
+ ($a:ident $b:ident $c:ident) => {
+ $a = $b + $c;
+ };
+}
+```
+
+See also [`format_macro_bodies`](#format_macro_bodies).
+
+
+## `format_macro_bodies`
+
+Format the bodies of macros.
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3355)
+
+#### `true` (default):
+
+```rust
+macro_rules! foo {
+ ($a: ident : $b: ty) => {
+ $a(42): $b;
+ };
+ ($a: ident $b: ident $c: ident) => {
+ $a = $b + $c;
+ };
+}
+```
+
+#### `false`:
+
+```rust
+macro_rules! foo {
+ ($a: ident : $b: ty) => { $a(42): $b; };
+ ($a: ident $b: ident $c: ident) => { $a=$b+$c; };
+}
+```
+
+See also [`format_macro_matchers`](#format_macro_matchers).
+
+
+## `format_strings`
+
+Format string literals where necessary
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3353)
+
+#### `false` (default):
+
+```rust
+fn main() {
+ let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet consectetur adipiscing";
+}
+```
+
+#### `true`:
+
+```rust
+fn main() {
+ let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet \
+ consectetur adipiscing";
+}
+```
+
+See also [`max_width`](#max_width).
-## `brace_style`
-
-Brace style for items
+## `hard_tabs`
-- **Default value**: `"SameLineWhere"`
-- **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
-- **Stable**: No
+Use tab characters for indentation, spaces for alignment
-### Functions
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-#### `"SameLineWhere"` (default):
+#### `false` (default):
```rust
-fn lorem() {
- // body
+fn lorem() -> usize {
+ 42 // spaces before 42
}
+```
-fn lorem(ipsum: usize) {
- // body
-}
+#### `true`:
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div,
-{
- // body
+```rust
+fn lorem() -> usize {
+ 42 // tabs before 42
}
```
-#### `"AlwaysNextLine"`:
+See also: [`tab_spaces`](#tab_spaces).
-```rust
-fn lorem()
-{
- // body
-}
-fn lorem(ipsum: usize)
-{
- // body
-}
+## `hide_parse_errors`
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div,
-{
- // body
-}
-```
+Do not show parse errors if the parser failed to parse files.
-#### `"PreferSameLine"`:
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3390)
-```rust
-fn lorem() {
- // body
-}
+## `ignore`
-fn lorem(ipsum: usize) {
- // body
-}
+Skip formatting files and directories that match the specified pattern.
+The pattern format is the same as [.gitignore](https://git-scm.com/docs/gitignore#_pattern_format). Be sure to use Unix/forwardslash `/` style paths. This path style will work on all platforms. Windows style paths with backslashes `\` are not supported.
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div, {
- // body
-}
+- **Default value**: format every file
+- **Possible values**: See an example below
+- **Stable**: No (tracking issue: #3395)
+
+### Example
+
+If you want to ignore specific files, put the following to your config file:
+
+```toml
+ignore = [
+ "src/types.rs",
+ "src/foo/bar.rs",
+]
```
-### Structs and enums
+If you want to ignore every file under `examples/`, put the following to your config file:
-#### `"SameLineWhere"` (default):
+```toml
+ignore = [
+ "examples",
+]
+```
-```rust
-struct Lorem {
- ipsum: bool,
-}
+If you want to ignore every file under the directory where you put your rustfmt.toml:
-struct Dolor<T>
-where
- T: Eq,
-{
- sit: T,
-}
+```toml
+ignore = ["/"]
```
-#### `"AlwaysNextLine"`:
+## `imports_indent`
+
+Indent style of imports
+
+- **Default Value**: `"Block"`
+- **Possible values**: `"Block"`, `"Visual"`
+- **Stable**: No (tracking issue: #3360)
+
+#### `"Block"` (default):
```rust
-struct Lorem
-{
- ipsum: bool,
-}
+use foo::{
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
+ zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,
+};
+```
-struct Dolor<T>
-where
- T: Eq,
-{
- sit: T,
-}
+#### `"Visual"`:
+
+```rust
+use foo::{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
+ zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz};
```
-#### `"PreferSameLine"`:
+See also: [`imports_layout`](#imports_layout).
+
+## `imports_layout`
+
+Item layout inside a imports block
+
+- **Default value**: "Mixed"
+- **Possible values**: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"
+- **Stable**: No (tracking issue: #3361)
+
+#### `"Mixed"` (default):
```rust
-struct Lorem {
- ipsum: bool,
-}
+use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-struct Dolor<T>
-where
- T: Eq, {
- sit: T,
-}
+use foo::{
+ aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
+ eeeeeeeeeeeeeeeeee, ffffffffffffffffff,
+};
```
+#### `"Horizontal"`:
-## `empty_item_single_line`
+**Note**: This option forces all imports onto one line and may exceed `max_width`.
-Put empty-body functions and impls on a single line
+```rust
+use foo::{xxx, yyy, zzz};
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+use foo::{aaa, bbb, ccc, ddd, eee, fff};
+```
-#### `true` (default):
+#### `"HorizontalVertical"`:
```rust
-fn lorem() {}
+use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-impl Lorem {}
+use foo::{
+ aaaaaaaaaaaaaaaaaa,
+ bbbbbbbbbbbbbbbbbb,
+ cccccccccccccccccc,
+ dddddddddddddddddd,
+ eeeeeeeeeeeeeeeeee,
+ ffffffffffffffffff,
+};
```
-#### `false`:
+#### `"Vertical"`:
```rust
-fn lorem() {
-}
+use foo::{
+ xxx,
+ yyy,
+ zzz,
+};
-impl Lorem {
-}
+use foo::{
+ aaa,
+ bbb,
+ ccc,
+ ddd,
+ eee,
+ fff,
+};
```
-See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
-
+## `indent_style`
-## `fn_single_line`
+Indent on expressions or items.
-Put single-expression functions on a single line
+- **Default value**: `"Block"`
+- **Possible values**: `"Block"`, `"Visual"`
+- **Stable**: No (tracking issue: #3346)
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+### Array
-#### `false` (default):
+#### `"Block"` (default):
```rust
-fn lorem() -> usize {
- 42
-}
-
-fn lorem() -> usize {
- let ipsum = 42;
- ipsum
+fn main() {
+ let lorem = vec![
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit",
+ ];
}
```
-#### `true`:
+#### `"Visual"`:
```rust
-fn lorem() -> usize { 42 }
-
-fn lorem() -> usize {
- let ipsum = 42;
- ipsum
+fn main() {
+ let lorem = vec!["ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit"];
}
```
-See also [`control_brace_style`](#control_brace_style).
-
-
-## `where_single_line`
-
-Forces the `where` clause to be laid out on a single line.
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+### Control flow
-#### `false` (default):
+#### `"Block"` (default):
```rust
-impl<T> Lorem for T
-where
- Option<T>: Ipsum,
-{
- // body
+fn main() {
+ if lorem_ipsum
+ && dolor_sit
+ && amet_consectetur
+ && lorem_sit
+ && dolor_consectetur
+ && amet_ipsum
+ && lorem_consectetur
+ {
+ // ...
+ }
}
```
-#### `true`:
+#### `"Visual"`:
```rust
-impl<T> Lorem for T
-where Option<T>: Ipsum
-{
- // body
+fn main() {
+ if lorem_ipsum
+ && dolor_sit
+ && amet_consectetur
+ && lorem_sit
+ && dolor_consectetur
+ && amet_ipsum
+ && lorem_consectetur
+ {
+ // ...
+ }
}
```
-See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
-
-
-## `force_explicit_abi`
+See also: [`control_brace_style`](#control_brace_style).
-Always print the abi for extern items
+### Function arguments
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: Yes
+#### `"Block"` (default):
-**Note:** Non-"C" ABIs are always printed. If `false` then "C" is removed.
+```rust
+fn lorem() {}
-#### `true` (default):
+fn lorem(ipsum: usize) {}
-```rust
-extern "C" {
- pub static lorem: c_int;
+fn lorem(
+ ipsum: usize,
+ dolor: usize,
+ sit: usize,
+ amet: usize,
+ consectetur: usize,
+ adipiscing: usize,
+ elit: usize,
+) {
+ // body
}
```
-#### `false`:
+#### `"Visual"`:
```rust
-extern {
- pub static lorem: c_int;
-}
-```
+fn lorem() {}
-## `format_strings`
+fn lorem(ipsum: usize) {}
-Format string literals where necessary
+fn lorem(ipsum: usize,
+ dolor: usize,
+ sit: usize,
+ amet: usize,
+ consectetur: usize,
+ adipiscing: usize,
+ elit: usize) {
+ // body
+}
+```
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+### Function calls
-#### `false` (default):
+#### `"Block"` (default):
```rust
fn main() {
- let lorem =
- "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet consectetur adipiscing";
+ lorem(
+ "lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit",
+ );
}
```
-#### `true`:
+#### `"Visual"`:
```rust
fn main() {
- let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet \
- consectetur adipiscing";
+ lorem("lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit");
}
```
-See also [`max_width`](#max_width).
-
-## `format_macro_matchers`
-
-Format the metavariable matching patterns in macros.
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+### Generics
-#### `false` (default):
+#### `"Block"` (default):
```rust
-macro_rules! foo {
- ($a: ident : $b: ty) => {
- $a(42): $b;
- };
- ($a: ident $b: ident $c: ident) => {
- $a = $b + $c;
- };
+fn lorem<
+ Ipsum: Eq = usize,
+ Dolor: Eq = usize,
+ Sit: Eq = usize,
+ Amet: Eq = usize,
+ Adipiscing: Eq = usize,
+ Consectetur: Eq = usize,
+ Elit: Eq = usize,
+>(
+ ipsum: Ipsum,
+ dolor: Dolor,
+ sit: Sit,
+ amet: Amet,
+ adipiscing: Adipiscing,
+ consectetur: Consectetur,
+ elit: Elit,
+) -> T {
+ // body
}
```
-#### `true`:
+#### `"Visual"`:
```rust
-macro_rules! foo {
- ($a:ident : $b:ty) => {
- $a(42): $b;
- };
- ($a:ident $b:ident $c:ident) => {
- $a = $b + $c;
- };
+fn lorem<Ipsum: Eq = usize,
+ Dolor: Eq = usize,
+ Sit: Eq = usize,
+ Amet: Eq = usize,
+ Adipiscing: Eq = usize,
+ Consectetur: Eq = usize,
+ Elit: Eq = usize>(
+ ipsum: Ipsum,
+ dolor: Dolor,
+ sit: Sit,
+ amet: Amet,
+ adipiscing: Adipiscing,
+ consectetur: Consectetur,
+ elit: Elit)
+ -> T {
+ // body
}
```
-See also [`format_macro_bodies`](#format_macro_bodies).
-
-
-## `format_macro_bodies`
-
-Format the bodies of macros.
-
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+#### Struct
-#### `true` (default):
+#### `"Block"` (default):
```rust
-macro_rules! foo {
- ($a: ident : $b: ty) => {
- $a(42): $b;
- };
- ($a: ident $b: ident $c: ident) => {
- $a = $b + $c;
+fn main() {
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
};
}
```
-#### `false`:
+#### `"Visual"`:
```rust
-macro_rules! foo {
- ($a: ident : $b: ty) => { $a(42): $b; };
- ($a: ident $b: ident $c: ident) => { $a=$b+$c; };
+fn main() {
+ let lorem = Lorem { ipsum: dolor,
+ sit: amet };
}
```
-See also [`format_macro_matchers`](#format_macro_matchers).
-
-
-## `hard_tabs`
-
-Use tab characters for indentation, spaces for alignment
+See also: [`struct_lit_single_line`](#struct_lit_single_line), [`indent_style`](#indent_style).
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: Yes
+### Where predicates
-#### `false` (default):
+#### `"Block"` (default):
```rust
-fn lorem() -> usize {
- 42 // spaces before 42
+fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
+where
+ Ipsum: Eq,
+ Dolor: Eq,
+ Sit: Eq,
+ Amet: Eq,
+{
+ // body
}
```
-#### `true`:
+#### `"Visual"`:
```rust
-fn lorem() -> usize {
- 42 // tabs before 42
+fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
+ where Ipsum: Eq,
+ Dolor: Eq,
+ Sit: Eq,
+ Amet: Eq
+{
+ // body
}
```
-See also: [`tab_spaces`](#tab_spaces).
-
+## `inline_attribute_width`
-## `imports_indent`
-
-Indent style of imports
+Write an item and its attribute on the same line if their combined width is below a threshold
-- **Default Value**: `"Block"`
-- **Possible values**: `"Block"`, `"Visual"`
-- **Stable**: No
+- **Default value**: 0
+- **Possible values**: any positive integer
+- **Stable**: No (tracking issue: #3343)
-#### `"Block"` (default):
+### Example
+#### `0` (default):
```rust
-use foo::{
- xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
- zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,
-};
+#[cfg(feature = "alloc")]
+use core::slice;
```
-#### `"Visual"`:
-
+#### `50`:
```rust
-use foo::{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
- zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz};
+#[cfg(feature = "alloc")] use core::slice;
```
-See also: [`imports_layout`](#imports_layout).
-
-## `imports_layout`
-
-Item layout inside a imports block
+## `license_template_path`
-- **Default value**: "Mixed"
-- **Possible values**: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"
-- **Stable**: No
+Check whether beginnings of files match a license template.
-#### `"Mixed"` (default):
+- **Default value**: `""`
+- **Possible values**: path to a license template file
+- **Stable**: No (tracking issue: #3352)
-```rust
-use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
+A license template is a plain text file which is matched literally against the
+beginning of each source file, except for `{}`-delimited blocks, which are
+matched as regular expressions. The following license template therefore
+matches strings like `// Copyright 2017 The Rust Project Developers.`, `//
+Copyright 2018 The Rust Project Developers.`, etc.:
-use foo::{
- aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
- eeeeeeeeeeeeeeeeee, ffffffffffffffffff,
-};
+```
+// Copyright {\d+} The Rust Project Developers.
```
-#### `"Horizontal"`:
+`\{`, `\}` and `\\` match literal braces / backslashes.
-**Note**: This option forces all imports onto one line and may exceed `max_width`.
+## `match_arm_blocks`
-```rust
-use foo::{xxx, yyy, zzz};
+Wrap the body of arms in blocks when it does not fit on the same line with the pattern of arms
-use foo::{aaa, bbb, ccc, ddd, eee, fff};
-```
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3373)
-#### `"HorizontalVertical"`:
+#### `true` (default):
```rust
-use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-
-use foo::{
- aaaaaaaaaaaaaaaaaa,
- bbbbbbbbbbbbbbbbbb,
- cccccccccccccccccc,
- dddddddddddddddddd,
- eeeeeeeeeeeeeeeeee,
- ffffffffffffffffff,
-};
+fn main() {
+ match lorem {
+ true => {
+ foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
+ }
+ false => println!("{}", sit),
+ }
+}
```
-#### `"Vertical"`:
+#### `false`:
```rust
-use foo::{
- xxx,
- yyy,
- zzz,
-};
-
-use foo::{
- aaa,
- bbb,
- ccc,
- ddd,
- eee,
- fff,
-};
+fn main() {
+ match lorem {
+ true =>
+ foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
+ false => println!("{}", sit),
+ }
+}
```
-## `merge_imports`
+See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
-Merge multiple imports into a single nested import.
+## `match_arm_leading_pipes`
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+Controls whether to include a leading pipe on match arms
-#### `false` (default):
+- **Default value**: `Never`
+- **Possible values**: `Always`, `Never`, `Preserve`
+- **Stable**: Yes
-```rust
-use foo::{a, c, d};
-use foo::{b, g};
-use foo::{e, f};
+#### `Never` (default):
+```rust
+// Leading pipes are removed from this:
+// fn foo() {
+// match foo {
+// | "foo" | "bar" => {}
+// | "baz"
+// | "something relatively long"
+// | "something really really really realllllllllllllly long" => println!("x"),
+// | "qux" => println!("y"),
+// _ => {}
+// }
+// }
+
+// Becomes
+fn foo() {
+ match foo {
+ "foo" | "bar" => {}
+ "baz"
+ | "something relatively long"
+ | "something really really really realllllllllllllly long" => println!("x"),
+ "qux" => println!("y"),
+ _ => {}
+ }
+}
```
-#### `true`:
-
+#### `Always`:
```rust
-use foo::{a, b, c, d, e, f, g};
+// Leading pipes are emitted on all arms of this:
+// fn foo() {
+// match foo {
+// "foo" | "bar" => {}
+// "baz"
+// | "something relatively long"
+// | "something really really really realllllllllllllly long" => println!("x"),
+// "qux" => println!("y"),
+// _ => {}
+// }
+// }
+
+// Becomes:
+fn foo() {
+ match foo {
+ | "foo" | "bar" => {}
+ | "baz"
+ | "something relatively long"
+ | "something really really really realllllllllllllly long" => println!("x"),
+ | "qux" => println!("y"),
+ | _ => {}
+ }
+}
```
+#### `Preserve`:
+```rust
+fn foo() {
+ match foo {
+ | "foo" | "bar" => {}
+ | "baz"
+ | "something relatively long"
+ | "something really really really realllllllllllllly long" => println!("x"),
+ | "qux" => println!("y"),
+ _ => {}
+ }
+
+ match baz {
+ "qux" => {}
+ "foo" | "bar" => {}
+ _ => {}
+ }
+}
+```
## `match_block_trailing_comma`
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3380)
#### `false` (default):
pub enum Foo {}
```
-## `force_multiline_blocks`
+## `imports_granularity`
-Force multiline closure and match arm bodies to be wrapped in a block
+How imports should be grouped into `use` statements. Imports will be merged or split to the configured level of granularity.
-- **Default value**: `false`
-- **Possible values**: `false`, `true`
+- **Default value**: `Preserve`
+- **Possible values**: `Preserve`, `Crate`, `Module`, `Item`
- **Stable**: No
-#### `false` (default):
+#### `Preserve` (default):
+
+Do not change the granularity of any imports and preserve the original structure written by the developer.
```rust
-fn main() {
- result.and_then(|maybe_value| match maybe_value {
- None => foo(),
- Some(value) => bar(),
- });
+use foo::b;
+use foo::b::{f, g};
+use foo::{a, c, d::e};
+use qux::{h, i};
+```
- match lorem {
- None => if ipsum {
- println!("Hello World");
- },
- Some(dolor) => foo(),
- }
-}
+#### `Crate`:
+
+Merge imports from the same crate into a single `use` statement. Conversely, imports from different crates are split into separate statements.
+
+```rust
+use foo::{
+ a, b,
+ b::{f, g},
+ c,
+ d::e,
+};
+use qux::{h, i};
```
-#### `true`:
+#### `Module`:
+
+Merge imports from the same module into a single `use` statement. Conversely, imports from different modules are split into separate statements.
```rust
-fn main() {
- result.and_then(|maybe_value| {
- match maybe_value {
- None => foo(),
- Some(value) => bar(),
- }
- });
+use foo::b::{f, g};
+use foo::d::e;
+use foo::{a, b, c};
+use qux::{h, i};
+```
- match lorem {
- None => {
- if ipsum {
- println!("Hello World");
- }
- }
- Some(dolor) => foo(),
- }
-}
+#### `Item`:
+
+Flatten imports so that each has its own `use` statement.
+
+```rust
+use foo::a;
+use foo::b;
+use foo::b::f;
+use foo::b::g;
+use foo::c;
+use foo::d::e;
+use qux::h;
+use qux::i;
+```
+
+## `merge_imports`
+
+This option is deprecated. Use `imports_granularity = "Crate"` instead.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+
+#### `false` (default):
+
+```rust
+use foo::{a, c, d};
+use foo::{b, g};
+use foo::{e, f};
+```
+
+#### `true`:
+
+```rust
+use foo::{a, b, c, d, e, f, g};
```
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3350)
#### `false` (default):
fn adipiscing() -> usize {}
```
+## `normalize_doc_attributes`
+
+Convert `#![doc]` and `#[doc]` attributes to `//!` and `///` doc comments.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3351)
+
+#### `false` (default):
+
+```rust
+#![doc = "Example documentation"]
+
+#[doc = "Example item documentation"]
+pub enum Foo {}
+```
+
+#### `true`:
+
+```rust
+//! Example documentation
+
+/// Example item documentation
+pub enum Foo {}
+```
+
+## `overflow_delimited_expr`
+
+When structs, slices, arrays, and block/array-like macros are used as the last
+argument in an expression list, allow them to overflow (like blocks/closures)
+instead of being indented on a new line.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3370)
+
+#### `false` (default):
+
+```rust
+fn example() {
+ foo(ctx, |param| {
+ action();
+ foo(param)
+ });
+
+ foo(
+ ctx,
+ Bar {
+ x: value,
+ y: value2,
+ },
+ );
+
+ foo(
+ ctx,
+ &[
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ],
+ );
+
+ foo(
+ ctx,
+ vec![
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ],
+ );
+}
+```
+
+#### `true`:
+
+```rust
+fn example() {
+ foo(ctx, |param| {
+ action();
+ foo(param)
+ });
+
+ foo(ctx, Bar {
+ x: value,
+ y: value2,
+ });
+
+ foo(ctx, &[
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ]);
+
+ foo(ctx, vec![
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ]);
+}
+```
+
## `remove_nested_parens`
Remove nested parens.
#### `false`:
```rust
-fn main() {
- ((((foo()))));
+fn main() {
+ ((((foo()))));
+}
+```
+
+
+## `reorder_impl_items`
+
+Reorder impl items. `type` and `const` are put first, then macros and methods.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3363)
+
+#### `false` (default)
+
+```rust
+struct Dummy;
+
+impl Iterator for Dummy {
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
+
+ type Item = i32;
+}
+```
+
+#### `true`
+
+```rust
+struct Dummy;
+
+impl Iterator for Dummy {
+ type Item = i32;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
}
```
-
## `reorder_imports`
Reorder import and extern crate statements alphabetically in groups (a group is
use sit;
```
+## `group_imports`
+
+Controls the strategy for how imports are grouped together.
+
+- **Default value**: `Preserve`
+- **Possible values**: `Preserve`, `StdExternalCrate`
+- **Stable**: No
+
+#### `Preserve` (default):
+
+Preserve the source file's import groups.
+
+```rust
+use super::update::convert_publish_payload;
+use chrono::Utc;
+
+use alloc::alloc::Layout;
+use juniper::{FieldError, FieldResult};
+use uuid::Uuid;
+
+use std::sync::Arc;
+
+use broker::database::PooledConnection;
+
+use super::schema::{Context, Payload};
+use crate::models::Event;
+use core::f32;
+```
+
+#### `StdExternalCrate`:
+
+Discard existing import groups, and create three groups for:
+1. `std`, `core` and `alloc`,
+2. external crates,
+3. `self`, `super` and `crate` imports.
+
+```rust
+use alloc::alloc::Layout;
+use core::f32;
+use std::sync::Arc;
+
+use broker::database::PooledConnection;
+use chrono::Utc;
+use juniper::{FieldError, FieldResult};
+use uuid::Uuid;
+
+use super::schema::{Context, Payload};
+use super::update::convert_publish_payload;
+use crate::models::Event;
+```
## `reorder_modules`
mod sit;
```
-**Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantic
+**Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantics
of the original source code.
-## `reorder_impl_items`
-
-Reorder impl items. `type` and `const` are put first, then macros and methods.
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
-
-#### `false` (default)
-
-```rust
-struct Dummy;
-
-impl Iterator for Dummy {
- fn next(&mut self) -> Option<Self::Item> {
- None
- }
+## `report_fixme`
- type Item = i32;
-}
-```
+Report `FIXME` items in comments.
-#### `true`
+- **Default value**: `"Never"`
+- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
+- **Stable**: No (tracking issue: #3394)
-```rust
-struct Dummy;
+Warns about any comments containing `FIXME` in them when set to `"Always"`. If
+it contains a `#X` (with `X` being a number) in parentheses following the
+`FIXME`, `"Unnumbered"` will ignore it.
-impl Iterator for Dummy {
- type Item = i32;
+See also [`report_todo`](#report_todo).
- fn next(&mut self) -> Option<Self::Item> {
- None
- }
-}
-```
## `report_todo`
- **Default value**: `"Never"`
- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3393)
Warns about any comments containing `TODO` in them when set to `"Always"`. If
it contains a `#X` (with `X` being a number) in parentheses following the
See also [`report_fixme`](#report_fixme).
-## `report_fixme`
-
-Report `FIXME` items in comments.
-
-- **Default value**: `"Never"`
-- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
-- **Stable**: No
-
-Warns about any comments containing `FIXME` in them when set to `"Always"`. If
-it contains a `#X` (with `X` being a number) in parentheses following the
-`FIXME`, `"Unnumbered"` will ignore it.
+## `required_version`
-See also [`report_todo`](#report_todo).
+Require a specific version of rustfmt. If you want to make sure that the
+specific version of rustfmt is used in your CI, use this option.
+- **Default value**: `CARGO_PKG_VERSION`
+- **Possible values**: any published version (e.g. `"0.3.8"`)
+- **Stable**: No (tracking issue: #3386)
## `skip_children`
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3389)
+
+## `single_line_if_else_max_width`
+
+Maximum line length for single line if-else expressions. A value of `0` (zero) results in if-else expressions always being broken into multiple lines. Note this occurs when `use_small_heuristics` is set to `Off`.
+
+- **Default value**: `50`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `single_line_if_else_max_width` will take precedence.
+
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
## `space_after_colon`
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3366)
#### `true` (default):
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3365)
#### `false` (default):
See also: [`space_after_colon`](#space_after_colon).
-## `struct_field_align_threshold`
-
-The maximum diff of width between struct fields to be aligned with each other.
-
-- **Default value** : 0
-- **Possible values**: any positive integer
-- **Stable**: No
-
-#### `0` (default):
-
-```rust
-struct Foo {
- x: u32,
- yy: u32,
- zzz: u32,
-}
-```
-
-#### `20`:
-
-```rust
-struct Foo {
- x: u32,
- yy: u32,
- zzz: u32,
-}
-```
-
## `spaces_around_ranges`
Put spaces around the .., ..=, and ... range operators
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3367)
#### `false` (default):
}
```
+## `struct_field_align_threshold`
+
+The maximum diff of width between struct fields to be aligned with each other.
+
+- **Default value** : 0
+- **Possible values**: any non-negative integer
+- **Stable**: No (tracking issue: #3371)
+
+#### `0` (default):
+
+```rust
+struct Foo {
+ x: u32,
+ yy: u32,
+ zzz: u32,
+}
+```
+
+#### `20`:
+
+```rust
+struct Foo {
+ x: u32,
+ yy: u32,
+ zzz: u32,
+}
+```
+
## `struct_lit_single_line`
Put small struct literals on a single line
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3357)
#### `true` (default):
See also: [`indent_style`](#indent_style).
+## `struct_lit_width`
+
+Maximum width in the body of a struct literal before falling back to vertical formatting. A value of `0` (zero) results in struct literals always being broken into multiple lines. Note this occurs when `use_small_heuristics` is set to `Off`.
+
+- **Default value**: `18`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `struct_lit_width` will take precedence.
+
+See also [`max_width`](#max_width), [`use_small_heuristics`](#use_small_heuristics), and [`struct_lit_single_line`](#struct_lit_single_line)
+
+## `struct_variant_width`
+
+Maximum width in the body of a struct variant before falling back to vertical formatting. A value of `0` (zero) results in struct literals always being broken into multiple lines. Note this occurs when `use_small_heuristics` is set to `Off`.
+
+- **Default value**: `35`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+
+By default this option is set as a percentage of [`max_width`](#max_width) provided by [`use_small_heuristics`](#use_small_heuristics), but a value set directly for `struct_variant_width` will take precedence.
+
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
## `tab_spaces`
- **Default value**: `"Vertical"`
- **Possible values**: `"Always"`, `"Never"`, `"Vertical"`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3379)
#### `"Vertical"` (default):
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3378)
#### `true` (default):
```rust
- **Default value**: `"Wide"`
- **Possible values**: `"Compressed"`, `"Wide"`
-- **Stable**: No
+- **Stable**: No (tracking issue: #3364)
#### `"Wide"` (default):
}
```
+## `unstable_features`
+
+Enable unstable features on the unstable channel.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3387)
+
## `use_field_init_shorthand`
Use field initialize shorthand if possible.
}
fn main() {
- let x = 1;
- let y = 2;
- let z = 3;
- let a = Foo { x: x, y: y, z: z };
-}
-```
-
-#### `true`:
-
-```rust
-struct Foo {
- x: u32,
- y: u32,
- z: u32,
-}
-
-fn main() {
- let x = 1;
- let y = 2;
- let z = 3;
- let a = Foo { x, y, z };
-}
-```
-
-## `use_try_shorthand`
-
-Replace uses of the try! macro by the ? shorthand
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: Yes
-
-#### `false` (default):
-
-```rust
-fn main() {
- let lorem = try!(ipsum.map(|dolor| dolor.sit()));
-}
-```
-
-#### `true`:
-
-```rust
-fn main() {
- let lorem = ipsum.map(|dolor| dolor.sit())?;
-}
-```
-
-
-## `wrap_comments`
-
-Break comments to fit on the line
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
-
-#### `false` (default):
-
-```rust
-// Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
-```
-
-#### `true`:
-
-```rust
-// Lorem ipsum dolor sit amet, consectetur adipiscing elit,
-// sed do eiusmod tempor incididunt ut labore et dolore
-// magna aliqua. Ut enim ad minim veniam, quis nostrud
-// exercitation ullamco laboris nisi ut aliquip ex ea
-// commodo consequat.
-```
-
-## `match_arm_blocks`
-
-Wrap the body of arms in blocks when it does not fit on the same line with the pattern of arms
-
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No
-
-#### `true` (default):
-
-```rust
-fn main() {
- match lorem {
- true => {
- foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
- }
- false => println!("{}", sit),
- }
+ let x = 1;
+ let y = 2;
+ let z = 3;
+ let a = Foo { x: x, y: y, z: z };
}
```
-#### `false`:
+#### `true`:
```rust
+struct Foo {
+ x: u32,
+ y: u32,
+ z: u32,
+}
+
fn main() {
- match lorem {
- true =>
- foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
- false => println!("{}", sit),
- }
+ let x = 1;
+ let y = 2;
+ let z = 3;
+ let a = Foo { x, y, z };
}
```
-See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
-
+## `use_small_heuristics`
-## `blank_lines_upper_bound`
+This option can be used to simplify the management and bulk updates of the granular width configuration settings ([`fn_call_width`](#fn_call_width), [`attr_fn_like_width`](#attr_fn_like_width), [`struct_lit_width`](#struct_lit_width), [`struct_variant_width`](#struct_variant_width), [`array_width`](#array_width), [`chain_width`](#chain_width), [`single_line_if_else_max_width`](#single_line_if_else_max_width)), that respectively control when formatted constructs are multi-lined/vertical based on width.
-Maximum number of blank lines which can be put between items. If more than this number of consecutive empty
-lines are found, they are trimmed down to match this integer.
+Note that explicitly provided values for the width configuration settings take precedence and override the calculated values determined by `use_small_heuristics`.
-- **Default value**: `1`
-- **Possible values**: *unsigned integer*
-- **Stable**: No
+- **Default value**: `"Default"`
+- **Possible values**: `"Default"`, `"Off"`, `"Max"`
+- **Stable**: Yes
-### Example
-Original Code:
+#### `Default` (default):
+When `use_small_heuristics` is set to `Default`, the values for the granular width settings are calculated as a ratio of the value for `max_width`.
+
+The ratios are:
+* [`fn_call_width`](#fn_call_width) - `60%`
+* [`attr_fn_like_width`](#attr_fn_like_width) - `70%`
+* [`struct_lit_width`](#struct_lit_width) - `18%`
+* [`struct_variant_width`](#struct_variant_width) - `35%`
+* [`array_width`](#array_width) - `60%`
+* [`chain_width`](#chain_width) - `60%`
+* [`single_line_if_else_max_width`](#single_line_if_else_max_width) - `50%`
+
+For example when `max_width` is set to `100`, the width settings are:
+* `fn_call_width=60`
+* `attr_fn_like_width=70`
+* `struct_lit_width=18`
+* `struct_variant_width=35`
+* `array_width=60`
+* `chain_width=60`
+* `single_line_if_else_max_width=50`
+
+and when `max_width` is set to `200`:
+* `fn_call_width=120`
+* `attr_fn_like_width=140`
+* `struct_lit_width=36`
+* `struct_variant_width=70`
+* `array_width=120`
+* `chain_width=120`
+* `single_line_if_else_max_width=100`
```rust
-#![rustfmt::skip]
-
-fn foo() {
- println!("a");
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit { amet: Consectetur, adipiscing: Elit },
}
+fn main() {
+ lorem(
+ "lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ );
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+ let lorem = Lorem { ipsum: dolor };
-fn bar() {
- println!("b");
-
-
- println!("c");
+ let lorem = if ipsum { dolor } else { sit };
}
```
-#### `1` (default):
+#### `Off`:
+When `use_small_heuristics` is set to `Off`, the granular width settings are functionally disabled and ignored. See the documentation for the respective width config options for specifics.
+
```rust
-fn foo() {
- println!("a");
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit {
+ amet: Consectetur,
+ adipiscing: Elit,
+ },
}
-fn bar() {
- println!("b");
+fn main() {
+ lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
- println!("c");
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+
+ let lorem = if ipsum {
+ dolor
+ } else {
+ sit
+ };
}
```
-#### `2`:
+#### `Max`:
+When `use_small_heuristics` is set to `Max`, then each granular width setting is set to the same value as `max_width`.
+
+So if `max_width` is set to `200`, then all the width settings are also set to `200`.
+* `fn_call_width=200`
+* `attr_fn_like_width=200`
+* `struct_lit_width=200`
+* `struct_variant_width=200`
+* `array_width=200`
+* `chain_width=200`
+* `single_line_if_else_max_width=200`
+
```rust
-fn foo() {
- println!("a");
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit { amet: Consectetur, adipiscing: Elit },
}
+fn main() {
+ lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-fn bar() {
- println!("b");
-
+ let lorem = Lorem { ipsum: dolor, sit: amet };
- println!("c");
+ let lorem = if ipsum { dolor } else { sit };
}
```
-See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
-
-## `blank_lines_lower_bound`
-Minimum number of blank lines which must be put between items. If two items have fewer blank lines between
-them, additional blank lines are inserted.
+See also:
+* [`max_width`](#max_width)
+* [`fn_call_width`](#fn_call_width)
+* [`attr_fn_like_width`](#attr_fn_like_width)
+* [`struct_lit_width`](#struct_lit_width)
+* [`struct_variant_width`](#struct_variant_width)
+* [`array_width`](#array_width)
+* [`chain_width`](#chain_width)
+* [`single_line_if_else_max_width`](#single_line_if_else_max_width)
-- **Default value**: `0`
-- **Possible values**: *unsigned integer*
-- **Stable**: No
+## `use_try_shorthand`
-### Example
-Original Code (rustfmt will not change it with the default value of `0`):
+Replace uses of the try! macro by the ? shorthand
-```rust
-#![rustfmt::skip]
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-fn foo() {
- println!("a");
-}
-fn bar() {
- println!("b");
- println!("c");
-}
-```
+#### `false` (default):
-#### `1`
```rust
-fn foo() {
-
- println!("a");
+fn main() {
+ let lorem = try!(ipsum.map(|dolor| dolor.sit()));
}
+```
-fn bar() {
-
- println!("b");
+#### `true`:
- println!("c");
+```rust
+fn main() {
+ let lorem = ipsum.map(|dolor| dolor.sit())?;
}
```
+## `version`
-## `required_version`
-
-Require a specific version of rustfmt. If you want to make sure that the
-specific version of rustfmt is used in your CI, use this option.
-
-- **Default value**: `CARGO_PKG_VERSION`
-- **Possible values**: any published version (e.g. `"0.3.8"`)
-- **Stable**: No
-
-## `hide_parse_errors`
-
-Do not show parse errors if the parser failed to parse files.
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No
+Which version of the formatting rules to use. `Version::One` is backwards-compatible
+with Rustfmt 1.0. Other versions are only backwards compatible within a major
+version number.
-## `color`
+- **Default value**: `One`
+- **Possible values**: `One`, `Two`
+- **Stable**: No (tracking issue: #3383)
-Whether to use colored output or not.
+### Example
-- **Default value**: `"Auto"`
-- **Possible values**: "Auto", "Always", "Never"
-- **Stable**: No
+```toml
+version = "Two"
+```
-## `unstable_features`
+## `where_single_line`
-Enable unstable features on stable channel.
+Forces the `where` clause to be laid out on a single line.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No
-
-## `license_template_path`
+- **Stable**: No (tracking issue: #3359)
-Check whether beginnings of files match a license template.
+#### `false` (default):
-- **Default value**: `""``
-- **Possible values**: path to a license template file
-- **Stable**: No
+```rust
+impl<T> Lorem for T
+where
+ Option<T>: Ipsum,
+{
+ // body
+}
+```
-A license template is a plain text file which is matched literally against the
-beginning of each source file, except for `{}`-delimited blocks, which are
-matched as regular expressions. The following license template therefore
-matches strings like `// Copyright 2017 The Rust Project Developers.`, `//
-Copyright 2018 The Rust Project Developers.`, etc.:
+#### `true`:
-```
-// Copyright {\d+} The Rust Project Developers.
+```rust
+impl<T> Lorem for T
+where Option<T>: Ipsum
+{
+ // body
+}
```
-`\{`, `\}` and `\\` match literal braces / backslashes.
+See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
-## `ignore`
-Skip formatting the specified files and directories.
+## `wrap_comments`
-- **Default value**: format every files
-- **Possible values**: See an example below
-- **Stable**: No
+Break comments to fit on the line
-### Example
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #3347)
-If you want to ignore specific files, put the following to your config file:
+#### `false` (default):
-```toml
-ignore = [
- "src/types.rs",
- "src/foo/bar.rs",
-]
+```rust
+// Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
```
-If you want to ignore every file under `examples/`, put the following to your config file:
+#### `true`:
-```toml
-ignore = [
- "examples",
-]
+```rust
+// Lorem ipsum dolor sit amet, consectetur adipiscing elit,
+// sed do eiusmod tempor incididunt ut labore et dolore
+// magna aliqua. Ut enim ad minim veniam, quis nostrud
+// exercitation ullamco laboris nisi ut aliquip ex ea
+// commodo consequat.
```
-## `edition`
-
-Specifies which edition is used by the parser.
-
-- **Default value**: `2015`
-- **Possible values**: `2015`, `2018`
-- **Stable**: No
-
-### Example
-
-If you want to format code that requires edition 2018, add the following to your config file:
-
-```toml
-edition = "2018"
-```
+# Internal Options
## `emit_mode`
## `make_backup`
Internal option, use `--backup`
+
+## `print_misformatted_file_names`
+
+Internal option, use `-l` or `--files-with-diff`
projects / rust.git / blobdiff