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 (tracking issue: #3346)
+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](https://github.com/rust-lang/rustfmt/issues/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](https://github.com/rust-lang/rustfmt/issues/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](https://github.com/rust-lang/rustfmt/issues/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)
+
+## `brace_style`
+
+Brace style for items
+
+- **Default value**: `"SameLineWhere"`
+- **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
+- **Stable**: No (tracking issue: [#3376](https://github.com/rust-lang/rustfmt/issues/3376))
+
+### Functions
+
+#### `"SameLineWhere"` (default):
```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 {
+fn lorem() {
// body
}
-```
-
-#### Struct
-#### `"Block"` (default):
+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
}
```
-#### `"Visual"`:
+#### `"AlwaysNextLine"`:
```rust
-fn main() {
- let lorem = Lorem { ipsum: dolor,
- sit: amet };
+fn lorem()
+{
+ // body
}
-```
-
-See also: [`struct_lit_single_line`](#struct_lit_single_line), [`indent_style`](#indent_style).
-
-### Where predicates
-#### `"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 (tracking issue: #3368)
-
-#### `"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](https://github.com/rust-lang/rustfmt/issues/3385))
## `combine_control_expr`
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3369)
+- **Stable**: No (tracking issue: [#3369](https://github.com/rust-lang/rustfmt/issues/3369))
#### `true` (default):
- **Default value**: `80`
- **Possible values**: any positive integer
-- **Stable**: No (tracking issue: #3349)
+- **Stable**: No (tracking issue: [#3349](https://github.com/rust-lang/rustfmt/issues/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 (tracking issue: #3384)
+- **Stable**: No (tracking issue: [#3384](https://github.com/rust-lang/rustfmt/issues/3384))
#### `false` (default):
- **Default value**: `"AlwaysSameLine"`
- **Possible values**: `"AlwaysNextLine"`, `"AlwaysSameLine"`, `"ClosingNextLine"`
-- **Stable**: No (tracking issue: #3377)
+- **Stable**: No (tracking issue: [#3377](https://github.com/rust-lang/rustfmt/issues/3377))
#### `"AlwaysSameLine"` (default):
## `disable_all_formatting`
-Don't reformat anything
+Don't reformat anything.
+
+Note that this option may be soft-deprecated in the future once the [ignore](#ignore) option is stabilized. Nightly toolchain users are encouraged to use [ignore](#ignore) instead when possible.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3388)
+- **Stable**: Yes
+
+## `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](https://github.com/rust-lang/rustfmt/issues/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](https://github.com/rust-lang/rustfmt/issues/3372))
+
+#### `0` (default):
+
+```rust
+enum Bar {
+ A = 0,
+ Bb = 1,
+ RandomLongVariantGoesHere = 10,
+ Ccc = 71,
+}
+
+enum Bar {
+ VeryLongVariantNameHereA = 0,
+ VeryLongVariantNameHereBb = 1,
+ VeryLongVariantNameHereCcc = 2,
+}
+```
+
+#### `20`:
+
+```rust
+enum Foo {
+ A = 0,
+ Bb = 1,
+ RandomLongVariantGoesHere = 10,
+ Ccc = 2,
+}
+
+enum Bar {
+ VeryLongVariantNameHereA = 0,
+ VeryLongVariantNameHereBb = 1,
+ VeryLongVariantNameHereCcc = 2,
+}
+```
+
## `error_on_line_overflow`
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3391)
+- **Stable**: No (tracking issue: [#3391](https://github.com/rust-lang/rustfmt/issues/3391))
See also [`max_width`](#max_width).
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3392)
+- **Stable**: No (tracking issue: [#3392](https://github.com/rust-lang/rustfmt/issues/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 (tracking issue: #3375)
+- **Stable**: Yes
#### `"Tall"` (default):
}
```
+## `fn_call_width`
-## `brace_style`
+Maximum width of the args of a function call before falling back to vertical formatting.
-Brace style for 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**: `"SameLineWhere"`
-- **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
-- **Stable**: No (tracking issue: #3376)
+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.
-### Functions
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-#### `"SameLineWhere"` (default):
+## `fn_single_line`
+
+Put single-expression functions on a single line
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3358](https://github.com/rust-lang/rustfmt/issues/3358))
+
+#### `false` (default):
```rust
-fn lorem() {
- // body
+fn lorem() -> usize {
+ 42
}
-fn lorem(ipsum: usize) {
- // body
+fn lorem() -> usize {
+ let ipsum = 42;
+ ipsum
}
+```
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div,
-{
- // body
+#### `true`:
+
+```rust
+fn lorem() -> usize { 42 }
+
+fn lorem() -> usize {
+ let ipsum = 42;
+ ipsum
}
```
-#### `"AlwaysNextLine"`:
+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
-fn lorem()
-{
- // body
+extern "C" {
+ pub static lorem: c_int;
}
+```
-fn lorem(ipsum: usize)
-{
- // body
+#### `false`:
+
+```rust
+extern {
+ pub static lorem: c_int;
}
+```
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div,
-{
- // body
+## `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](https://github.com/rust-lang/rustfmt/issues/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(),
+ }
}
```
-#### `"PreferSameLine"`:
+#### `true`:
```rust
-fn lorem() {
- // body
+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(),
+ }
}
+```
-fn lorem(ipsum: usize) {
- // body
+
+## `format_code_in_doc_comments`
+
+Format code snippet included in doc comments.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3348](https://github.com/rust-lang/rustfmt/issues/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
}
+```
-fn lorem<T>(ipsum: T)
-where
- T: Add + Sub + Mul + Div, {
- // body
+#### `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
}
```
-### Structs and enums
+## `format_generated_files`
-#### `"SameLineWhere"` (default):
+Format generated files. A file is considered generated
+if any of the first five lines contain a `@generated` comment marker.
+By default, generated files are reformatted, i. e. `@generated` marker is ignored.
+This option is currently ignored for stdin (`@generated` in stdin is ignored.)
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#5080](https://github.com/rust-lang/rustfmt/issues/5080))
+
+## `format_macro_matchers`
+
+Format the metavariable matching patterns in macros.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3354](https://github.com/rust-lang/rustfmt/issues/3354))
+
+#### `false` (default):
```rust
-struct Lorem {
- ipsum: bool,
+macro_rules! foo {
+ ($a: ident : $b: ty) => {
+ $a(42): $b;
+ };
+ ($a: ident $b: ident $c: ident) => {
+ $a = $b + $c;
+ };
}
+```
-struct Dolor<T>
-where
- T: Eq,
-{
- sit: T,
+#### `true`:
+
+```rust
+macro_rules! foo {
+ ($a:ident : $b:ty) => {
+ $a(42): $b;
+ };
+ ($a:ident $b:ident $c:ident) => {
+ $a = $b + $c;
+ };
+}
+```
+
+See also [`format_macro_bodies`](#format_macro_bodies).
+
+
+## `format_macro_bodies`
+
+Format the bodies of macros.
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3355](https://github.com/rust-lang/rustfmt/issues/3355))
+
+#### `true` (default):
+
+```rust
+macro_rules! foo {
+ ($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](https://github.com/rust-lang/rustfmt/issues/3353))
+
+#### `false` (default):
+
+```rust
+fn main() {
+ let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet consectetur adipiscing";
}
```
-#### `"AlwaysNextLine"`:
+#### `true`:
```rust
-struct Lorem
-{
- ipsum: bool,
-}
-
-struct Dolor<T>
-where
- T: Eq,
-{
- sit: T,
+fn main() {
+ let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet \
+ consectetur adipiscing";
}
```
-#### `"PreferSameLine"`:
+See also [`max_width`](#max_width).
+
+## `hard_tabs`
+
+Use tab characters for indentation, spaces for alignment
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
+
+#### `false` (default):
```rust
-struct Lorem {
- ipsum: bool,
+fn lorem() -> usize {
+ 42 // spaces before 42
}
+```
-struct Dolor<T>
-where
- T: Eq, {
- sit: T,
+#### `true`:
+
+```rust
+fn lorem() -> usize {
+ 42 // tabs before 42
}
```
+See also: [`tab_spaces`](#tab_spaces).
-## `empty_item_single_line`
+## `hex_literal_case`
-Put empty-body functions and impls on a single line
+Control the case of the letters in hexadecimal literal values
-- **Default value**: `true`
+- **Default value**: `Preserve`
+- **Possible values**: `Upper`, `Lower`
+- **Stable**: No (tracking issue: [#5081](https://github.com/rust-lang/rustfmt/issues/5081))
+
+## `hide_parse_errors`
+
+Do not show parse errors if the parser failed to parse files.
+
+- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3356)
+- **Stable**: No (tracking issue: [#3390](https://github.com/rust-lang/rustfmt/issues/3390))
-#### `true` (default):
+## `ignore`
-```rust
-fn lorem() {}
+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.
-impl Lorem {}
-```
+- **Default value**: format every file
+- **Possible values**: See an example below
+- **Stable**: No (tracking issue: [#3395](https://github.com/rust-lang/rustfmt/issues/3395))
-#### `false`:
+### Example
-```rust
-fn lorem() {
-}
+If you want to ignore specific files, put the following to your config file:
-impl Lorem {
-}
+```toml
+ignore = [
+ "src/types.rs",
+ "src/foo/bar.rs",
+]
```
-See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
+If you want to ignore every file under `examples/`, put the following to your config file:
+```toml
+ignore = [
+ "examples",
+]
+```
-## `enum_discrim_align_threshold`
+If you want to ignore every file under the directory where you put your rustfmt.toml:
-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.
+```toml
+ignore = ["/"]
+```
-Note that this is not how much whitespace is inserted, but instead the longest variant name that
-doesn't get ignored when aligning.
+## `imports_indent`
-- **Default value** : 0
-- **Possible values**: any positive integer
-- **Stable**: No (tracking issue: #3372)
+Indent style of imports
-#### `0` (default):
+- **Default Value**: `"Block"`
+- **Possible values**: `"Block"`, `"Visual"`
+- **Stable**: No (tracking issue: [#3360](https://github.com/rust-lang/rustfmt/issues/3360))
+
+#### `"Block"` (default):
```rust
-enum Bar {
- A = 0,
- Bb = 1,
- RandomLongVariantGoesHere = 10,
- Ccc = 71,
-}
+use foo::{
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
+ zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,
+};
+```
-enum Bar {
- VeryLongVariantNameHereA = 0,
- VeryLongVariantNameHereBb = 1,
- VeryLongVariantNameHereCcc = 2,
-}
+#### `"Visual"`:
+
+```rust
+use foo::{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
+ zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz};
```
-#### `20`:
+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](https://github.com/rust-lang/rustfmt/issues/3361))
+
+#### `"Mixed"` (default):
```rust
-enum Foo {
- A = 0,
- Bb = 1,
- RandomLongVariantGoesHere = 10,
- Ccc = 2,
-}
+use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-enum Bar {
- VeryLongVariantNameHereA = 0,
- VeryLongVariantNameHereBb = 1,
- VeryLongVariantNameHereCcc = 2,
-}
+use foo::{
+ aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
+ eeeeeeeeeeeeeeeeee, ffffffffffffffffff,
+};
```
+#### `"Horizontal"`:
-## `fn_single_line`
+**Note**: This option forces all imports onto one line and may exceed `max_width`.
-Put single-expression functions on a single line
+```rust
+use foo::{xxx, yyy, zzz};
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3358)
+use foo::{aaa, bbb, ccc, ddd, eee, fff};
+```
-#### `false` (default):
+#### `"HorizontalVertical"`:
```rust
-fn lorem() -> usize {
- 42
-}
+use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
-fn lorem() -> usize {
- let ipsum = 42;
- ipsum
-}
+use foo::{
+ aaaaaaaaaaaaaaaaaa,
+ bbbbbbbbbbbbbbbbbb,
+ cccccccccccccccccc,
+ dddddddddddddddddd,
+ eeeeeeeeeeeeeeeeee,
+ ffffffffffffffffff,
+};
```
-#### `true`:
+#### `"Vertical"`:
```rust
-fn lorem() -> usize { 42 }
+use foo::{
+ xxx,
+ yyy,
+ zzz,
+};
-fn lorem() -> usize {
- let ipsum = 42;
- ipsum
-}
+use foo::{
+ aaa,
+ bbb,
+ ccc,
+ ddd,
+ eee,
+ fff,
+};
```
-See also [`control_brace_style`](#control_brace_style).
+## `indent_style`
+Indent on expressions or items.
-## `where_single_line`
+- **Default value**: `"Block"`
+- **Possible values**: `"Block"`, `"Visual"`
+- **Stable**: No (tracking issue: [#3346](https://github.com/rust-lang/rustfmt/issues/3346))
-Forces the `where` clause to be laid out on a single line.
+### Array
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3359)
+#### `"Block"` (default):
-#### `false` (default):
+```rust
+fn main() {
+ let lorem = vec![
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit",
+ ];
+}
+```
+
+#### `"Visual"`:
```rust
-impl<T> Lorem for T
-where
- Option<T>: Ipsum,
-{
- // body
+fn main() {
+ let lorem = vec!["ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ "elit"];
}
```
-#### `true`:
+### Control flow
+
+#### `"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
+ {
+ // ...
+ }
}
```
-See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
+#### `"Visual"`:
+```rust
+fn main() {
+ if lorem_ipsum
+ && dolor_sit
+ && amet_consectetur
+ && lorem_sit
+ && dolor_consectetur
+ && amet_ipsum
+ && lorem_consectetur
+ {
+ // ...
+ }
+}
+```
-## `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 (tracking issue: #3353)
+### 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 (tracking issue: #3354)
+### 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 + $c;
- };
+fn lorem<Ipsum: Eq = usize,
+ Dolor: Eq = usize,
+ Sit: Eq = usize,
+ Amet: Eq = usize,
+ Adipiscing: Eq = usize,
+ Consectetur: Eq = usize,
+ Elit: Eq = usize>(
+ ipsum: Ipsum,
+ dolor: Dolor,
+ sit: Sit,
+ amet: Amet,
+ adipiscing: Adipiscing,
+ consectetur: Consectetur,
+ elit: Elit)
+ -> T {
+ // body
}
```
-See also [`format_macro_bodies`](#format_macro_bodies).
-
-
-## `format_macro_bodies`
-
-Format the bodies of macros.
-
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3355)
+#### Struct
-#### `true` (default):
+#### `"Block"` (default):
```rust
-macro_rules! foo {
- ($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).
-
-
-## `imports_indent`
+## `inline_attribute_width`
-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 (tracking issue: #3360)
+- **Default value**: 0
+- **Possible values**: any positive integer
+- **Stable**: No (tracking issue: [#3343](https://github.com/rust-lang/rustfmt/issues/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
-
-- **Default value**: "Mixed"
-- **Possible values**: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"
-- **Stable**: No (tracking issue: #3361)
+## `license_template_path`
-#### `"Mixed"` (default):
+Check whether beginnings of files match a license template.
-```rust
-use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
+- **Default value**: `""`
+- **Possible values**: path to a license template file
+- **Stable**: No (tracking issue: [#3352](https://github.com/rust-lang/rustfmt/issues/3352))
-use foo::{
- aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
- eeeeeeeeeeeeeeeeee, ffffffffffffffffff,
-};
+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.:
+
+```
+// 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};
+Controls whether arm bodies are wrapped in cases where the first line of the body cannot fit on the same line as the `=>` operator.
-use foo::{aaa, bbb, ccc, ddd, eee, fff};
-```
+The Style Guide requires that bodies are block wrapped by default if a line break is required after the `=>`, but this option can be used to disable that behavior to prevent wrapping arm bodies in that event, so long as the body does not contain multiple statements nor line comments.
-#### `"HorizontalVertical"`:
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3373](https://github.com/rust-lang/rustfmt/issues/3373))
-```rust
-use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
+#### `true` (default):
-use foo::{
- aaaaaaaaaaaaaaaaaa,
- bbbbbbbbbbbbbbbbbb,
- cccccccccccccccccc,
- dddddddddddddddddd,
- eeeeeeeeeeeeeeeeee,
- ffffffffffffffffff,
-};
+```rust
+fn main() {
+ match lorem {
+ ipsum => {
+ foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
+ }
+ dolor => println!("{}", sit),
+ sit => foo(
+ "foooooooooooooooooooooooo",
+ "baaaaaaaaaaaaaaaaaaaaaaaarr",
+ "baaaaaaaaaaaaaaaaaaaazzzzzzzzzzzzz",
+ "qqqqqqqqquuuuuuuuuuuuuuuuuuuuuuuuuuxxx",
+ ),
+ }
+}
```
-#### `"Vertical"`:
+#### `false`:
```rust
-use foo::{
- xxx,
- yyy,
- zzz,
-};
-
-use foo::{
- aaa,
- bbb,
- ccc,
- ddd,
- eee,
- fff,
-};
+fn main() {
+ match lorem {
+ lorem =>
+ foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
+ ipsum => println!("{}", sit),
+ sit => foo(
+ "foooooooooooooooooooooooo",
+ "baaaaaaaaaaaaaaaaaaaaaaaarr",
+ "baaaaaaaaaaaaaaaaaaaazzzzzzzzzzzzz",
+ "qqqqqqqqquuuuuuuuuuuuuuuuuuuuuuuuuuxxx",
+ ),
+ }
+}
```
-## `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 (tracking issue: #3362)
+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 (tracking issue: #3380)
+- **Stable**: Yes
#### `false` (default):
#### `false`:
```rust
+#[derive(Eq, PartialEq, Debug, Copy, Clone)]
+pub enum Bar {}
+
#[derive(Eq, PartialEq)]
#[derive(Debug)]
#[derive(Copy, Clone)]
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**: `Preserve`
+- **Possible values**: `Preserve`, `Crate`, `Module`, `Item`, `One`
+- **Stable**: No (tracking issue: [#4991](https://github.com/rust-lang/rustfmt/issues/4991))
+
+#### `Preserve` (default):
+
+Do not change the granularity of any imports and preserve the original structure written by the developer.
+
+```rust
+use foo::b;
+use foo::b::{f, g};
+use foo::{a, c, d::e};
+use qux::{h, i};
+```
+
+#### `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};
+```
+
+#### `Module`:
+
+Merge imports from the same module into a single `use` statement. Conversely, imports from different modules are split into separate statements.
+
+```rust
+use foo::b::{f, g};
+use foo::d::e;
+use foo::{a, b, c};
+use qux::{h, i};
+```
+
+#### `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;
+```
+
+#### `One`:
+
+Merge all imports into a single `use` statement as long as they have the same visibility.
+
+```rust
+pub use foo::{x, y};
+use {
+ bar::{
+ a,
+ b::{self, f, g},
+ c,
+ d::e,
+ },
+ qux::{h, i},
+};
+```
+
+## `merge_imports`
+
+This option is deprecated. Use `imports_granularity = "Crate"` instead.
- **Default value**: `false`
-- **Possible values**: `false`, `true`
-- **Stable**: No (tracking issue: #3374)
+- **Possible values**: `true`, `false`
#### `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(),
- }
-}
+use foo::{a, c, d};
+use foo::{b, g};
+use foo::{e, f};
```
#### `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(),
- }
-}
+use foo::{a, b, c, d, e, f, g};
```
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3350)
+- **Stable**: No (tracking issue: [#3350](https://github.com/rust-lang/rustfmt/issues/3350))
#### `false` (default):
fn adipiscing() -> usize {}
```
-## `remove_nested_parens`
+## `normalize_doc_attributes`
-Remove nested parens.
+Convert `#![doc]` and `#[doc]` attributes to `//!` and `///` doc comments.
-- **Default value**: `true`,
+- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: Yes
+- **Stable**: No (tracking issue: [#3351](https://github.com/rust-lang/rustfmt/issues/3351))
+#### `false` (default):
-#### `true` (default):
```rust
-fn main() {
- (foo());
-}
+#![doc = "Example documentation"]
+
+#[doc = "Example item documentation"]
+pub enum Bar {}
+
+/// Example item documentation
+pub enum Foo {}
```
-#### `false`:
+#### `true`:
+
```rust
-fn main() {
- ((((foo()))));
-}
-```
+//! Example documentation
+/// Example item documentation
+pub enum Foo {}
+```
-## `reorder_imports`
+## `overflow_delimited_expr`
-Reorder import and extern crate statements alphabetically in groups (a group is
-separated by a newline).
+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**: `true`
+- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: Yes
+- **Stable**: No (tracking issue: [#3370](https://github.com/rust-lang/rustfmt/issues/3370))
-#### `true` (default):
+#### `false` (default):
```rust
-use dolor;
-use ipsum;
-use lorem;
-use sit;
+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,
+ ],
+ );
+}
```
-#### `false`:
+#### `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,
+ ]);
-```rust
-use lorem;
-use ipsum;
-use dolor;
-use sit;
+ foo(ctx, vec![
+ MAROON_TOMATOES,
+ PURPLE_POTATOES,
+ ORGANE_ORANGES,
+ GREEN_PEARS,
+ RED_APPLES,
+ ]);
+}
```
+## `remove_nested_parens`
-## `reorder_modules`
-
-Reorder `mod` declarations alphabetically in group.
+Remove nested parens.
-- **Default value**: `true`
+- **Default value**: `true`,
- **Possible values**: `true`, `false`
- **Stable**: Yes
-#### `true` (default)
+#### `true` (default):
```rust
-mod a;
-mod b;
-
-mod dolor;
-mod ipsum;
-mod lorem;
-mod sit;
+fn main() {
+ (foo());
+}
```
-#### `false`
-
+#### `false`:
```rust
-mod b;
-mod a;
+fn main() {
+ (foo());
-mod lorem;
-mod ipsum;
-mod dolor;
-mod sit;
+ ((((foo()))));
+}
```
-**Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantics
-of the original source code.
## `reorder_impl_items`
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3363)
+- **Stable**: No (tracking issue: [#3363](https://github.com/rust-lang/rustfmt/issues/3363))
#### `false` (default)
type Item = i32;
}
+
+impl Iterator for Dummy {
+ type Item = i32;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
+}
```
#### `true`
}
```
-## `report_todo`
-
-Report `TODO` items in comments.
-
-- **Default value**: `"Never"`
-- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
-- **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
-`TODO`, `"Unnumbered"` will ignore it.
-
-See also [`report_fixme`](#report_fixme).
-
-## `report_fixme`
-
-Report `FIXME` items in comments.
-
-- **Default value**: `"Never"`
-- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
-- **Stable**: No (tracking issue: #3394)
-
-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.
-
-See also [`report_todo`](#report_todo).
-
-
-## `skip_children`
-
-Don't reformat out of line modules
-
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3389)
-
-## `space_after_colon`
+## `reorder_imports`
-Leave a space after the colon.
+Reorder import and extern crate statements alphabetically in groups (a group is
+separated by a newline).
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3366)
+- **Stable**: Yes
#### `true` (default):
```rust
-fn lorem<T: Eq>(t: T) {
- let lorem: Dolor = Lorem {
- ipsum: dolor,
- sit: amet,
- };
-}
+use dolor;
+use ipsum;
+use lorem;
+use sit;
```
#### `false`:
```rust
-fn lorem<T:Eq>(t:T) {
- let lorem:Dolor = Lorem {
- ipsum:dolor,
- sit:amet,
- };
-}
+use lorem;
+use ipsum;
+use dolor;
+use sit;
```
-See also: [`space_before_colon`](#space_before_colon).
+## `group_imports`
-## `space_before_colon`
+Controls the strategy for how consecutive imports are grouped together.
-Leave a space before the colon.
+Controls the strategy for grouping sets of consecutive imports. Imports may contain newlines between imports and still be grouped together as a single set, but other statements between imports will result in different grouping sets.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3365)
+- **Default value**: `Preserve`
+- **Possible values**: `Preserve`, `StdExternalCrate`, `One`
+- **Stable**: No (tracking issue: [#5083](https://github.com/rust-lang/rustfmt/issues/5083))
-#### `false` (default):
+Each set of imports (one or more `use` statements, optionally separated by newlines) will be formatted independently. Other statements such as `mod ...` or `extern crate ...` will cause imports to not be grouped together.
-```rust
-fn lorem<T: Eq>(t: T) {
- let lorem: Dolor = Lorem {
- ipsum: dolor,
- sit: amet,
- };
-}
-```
+#### `Preserve` (default):
-#### `true`:
+Preserve the source file's import groups.
```rust
-fn lorem<T : Eq>(t : T) {
- let lorem : Dolor = Lorem {
- ipsum : dolor,
- sit : amet,
- };
-}
-```
+use super::update::convert_publish_payload;
+use chrono::Utc;
-See also: [`space_after_colon`](#space_after_colon).
+use alloc::alloc::Layout;
+use juniper::{FieldError, FieldResult};
+use uuid::Uuid;
-## `struct_field_align_threshold`
+use std::sync::Arc;
-The maximum diff of width between struct fields to be aligned with each other.
+use broker::database::PooledConnection;
-- **Default value** : 0
-- **Possible values**: any non-negative integer
-- **Stable**: No (tracking issue: #3371)
+use super::schema::{Context, Payload};
+use crate::models::Event;
+use core::f32;
+```
-#### `0` (default):
+#### `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
-struct Foo {
- x: u32,
- yy: u32,
- zzz: u32,
-}
+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;
```
-#### `20`:
+#### `One`:
+
+Discard existing import groups, and create a single group for everything
```rust
-struct Foo {
- x: u32,
- yy: u32,
- zzz: u32,
-}
+use super::schema::{Context, Payload};
+use super::update::convert_publish_payload;
+use crate::models::Event;
+use alloc::alloc::Layout;
+use broker::database::PooledConnection;
+use chrono::Utc;
+use core::f32;
+use juniper::{FieldError, FieldResult};
+use std::sync::Arc;
+use uuid::Uuid;
```
-## `spaces_around_ranges`
+## `reorder_modules`
-Put spaces around the .., ..=, and ... range operators
+Reorder `mod` declarations alphabetically in group.
-- **Default value**: `false`
+- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3367)
+- **Stable**: Yes
-#### `false` (default):
+#### `true` (default)
```rust
-fn main() {
- let lorem = 0..10;
- let ipsum = 0..=10;
-
- match lorem {
- 1..5 => foo(),
- _ => bar,
- }
-
- match lorem {
- 1..=5 => foo(),
- _ => bar,
- }
+mod a;
+mod b;
- match lorem {
- 1...5 => foo(),
- _ => bar,
- }
-}
+mod dolor;
+mod ipsum;
+mod lorem;
+mod sit;
```
-#### `true`:
+#### `false`
```rust
-fn main() {
- let lorem = 0 .. 10;
- let ipsum = 0 ..= 10;
-
- match lorem {
- 1 .. 5 => foo(),
- _ => bar,
- }
-
- match lorem {
- 1 ..= 5 => foo(),
- _ => bar,
- }
+mod b;
+mod a;
- match lorem {
- 1 ... 5 => foo(),
- _ => bar,
- }
-}
+mod lorem;
+mod ipsum;
+mod dolor;
+mod sit;
```
-## `struct_lit_single_line`
-
-Put small struct literals on a single line
-
-- **Default value**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3357)
-
-#### `true` (default):
+**Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantics
+of the original source code.
-```rust
-fn main() {
- let lorem = Lorem { foo: bar, baz: ofo };
-}
-```
+## `report_fixme`
-#### `false`:
+Report `FIXME` items in comments.
-```rust
-fn main() {
- let lorem = Lorem {
- foo: bar,
- baz: ofo,
- };
-}
-```
+- **Default value**: `"Never"`
+- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
+- **Stable**: No (tracking issue: [#3394](https://github.com/rust-lang/rustfmt/issues/3394))
-See also: [`indent_style`](#indent_style).
+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.
+See also [`report_todo`](#report_todo).
-## `tab_spaces`
-Number of spaces per tab
+## `report_todo`
-- **Default value**: `4`
-- **Possible values**: any positive integer
-- **Stable**: Yes
+Report `TODO` items in comments.
-#### `4` (default):
+- **Default value**: `"Never"`
+- **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
+- **Stable**: No (tracking issue: [#3393](https://github.com/rust-lang/rustfmt/issues/3393))
-```rust
-fn lorem() {
- let ipsum = dolor();
- let sit = vec![
- "amet consectetur adipiscing elit amet",
- "consectetur adipiscing elit amet consectetur.",
- ];
-}
-```
+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
+`TODO`, `"Unnumbered"` will ignore it.
-#### `2`:
+See also [`report_fixme`](#report_fixme).
-```rust
-fn lorem() {
- let ipsum = dolor();
- let sit = vec![
- "amet consectetur adipiscing elit amet",
- "consectetur adipiscing elit amet consectetur.",
- ];
-}
-```
+## `required_version`
-See also: [`hard_tabs`](#hard_tabs).
+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](https://github.com/rust-lang/rustfmt/issues/3386))
-## `trailing_comma`
+## `short_array_element_width_threshold`
-How to handle trailing commas for lists
+The width threshold for an array element to be considered "short".
-- **Default value**: `"Vertical"`
-- **Possible values**: `"Always"`, `"Never"`, `"Vertical"`
-- **Stable**: No (tracking issue: #3379)
+The layout of an array is dependent on the length of each of its elements.
+If the length of every element in an array is below this threshold (all elements are "short") then the array can be formatted in the mixed/compressed style, but if any one element has a length that exceeds this threshold then the array elements will have to be formatted vertically.
-#### `"Vertical"` (default):
+- **Default value**: `10`
+- **Possible values**: any positive integer that is less than or equal to the value specified for [`max_width`](#max_width)
+- **Stable**: Yes
+#### `10` (default):
```rust
fn main() {
- let Lorem { ipsum, dolor, sit } = amet;
- let Lorem {
- ipsum,
- dolor,
- sit,
- amet,
- consectetur,
- adipiscing,
- } = elit;
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000,
+ 0xaaaaaaaaaaaaaaaa,
+ 0xbbbbbbbbbbbbbbbb,
+ 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
}
```
-
-#### `"Always"`:
-
+#### `20`:
```rust
fn main() {
- let Lorem { ipsum, dolor, sit, } = amet;
- let Lorem {
- ipsum,
- dolor,
- sit,
- amet,
- consectetur,
- adipiscing,
- } = elit;
+ pub const FORMAT_TEST: [u64; 5] = [
+ 0x0000000000000000, 0xaaaaaaaaaaaaaaaa, 0xbbbbbbbbbbbbbbbb, 0xcccccccccccccccc,
+ 0xdddddddddddddddd,
+ ];
}
```
+See also [`max_width`](#max_width).
-#### `"Never"`:
+## `skip_children`
-```rust
-fn main() {
- let Lorem { ipsum, dolor, sit } = amet;
- let Lorem {
- ipsum,
- dolor,
- sit,
- amet,
- consectetur,
- adipiscing
- } = elit;
-}
-```
+Don't reformat out of line modules
-See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3389](https://github.com/rust-lang/rustfmt/issues/3389))
-## `trailing_semicolon`
+## `single_line_if_else_max_width`
-Add trailing semicolon after break, continue and return
+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**: `true`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3378)
+- **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
-#### `true` (default):
-```rust
-fn foo() -> usize {
- return 0;
-}
-```
+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.
-#### `false`:
-```rust
-fn foo() -> usize {
- return 0
-}
-```
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
-## `type_punctuation_density`
+## `space_after_colon`
-Determines if `+` or `=` are wrapped in spaces in the punctuation of types
+Leave a space after the colon.
-- **Default value**: `"Wide"`
-- **Possible values**: `"Compressed"`, `"Wide"`
-- **Stable**: No (tracking issue: #3364)
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3366](https://github.com/rust-lang/rustfmt/issues/3366))
-#### `"Wide"` (default):
+#### `true` (default):
```rust
-fn lorem<Ipsum: Dolor + Sit = Amet>() {
- // body
+fn lorem<T: Eq>(t: T) {
+ let lorem: Dolor = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
}
```
-#### `"Compressed"`:
+#### `false`:
```rust
-fn lorem<Ipsum: Dolor+Sit=Amet>() {
- // body
+fn lorem<T:Eq>(t:T) {
+ let lorem:Dolor = Lorem {
+ ipsum:dolor,
+ sit:amet,
+ };
}
```
-## `use_field_init_shorthand`
+See also: [`space_before_colon`](#space_before_colon).
-Use field initialize shorthand if possible.
+## `space_before_colon`
+
+Leave a space before the colon.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: Yes
+- **Stable**: No (tracking issue: [#3365](https://github.com/rust-lang/rustfmt/issues/3365))
#### `false` (default):
```rust
-struct Foo {
- x: u32,
- y: u32,
- z: u32,
-}
-
-fn main() {
- let x = 1;
- let y = 2;
- let z = 3;
- let a = Foo { x: x, y: y, z: z };
+fn lorem<T: Eq>(t: T) {
+ let lorem: Dolor = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
}
```
#### `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 };
+fn lorem<T : Eq>(t : T) {
+ let lorem : Dolor = Lorem {
+ ipsum : dolor,
+ sit : amet,
+ };
}
```
-## `use_try_shorthand`
+See also: [`space_after_colon`](#space_after_colon).
-Replace uses of the try! macro by the ? shorthand
+## `spaces_around_ranges`
+
+Put spaces around the .., ..=, and ... range operators
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: Yes
+- **Stable**: No (tracking issue: [#3367](https://github.com/rust-lang/rustfmt/issues/3367))
#### `false` (default):
```rust
fn main() {
- let lorem = try!(ipsum.map(|dolor| dolor.sit()));
-}
-```
-
-#### `true`:
-
-```rust
-fn main() {
- let lorem = ipsum.map(|dolor| dolor.sit())?;
-}
-```
-
-## `format_code_in_doc_comments`
-
-Format code snippet included in doc comments.
+ let lorem = 0..10;
+ let ipsum = 0..=10;
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3348)
+ match lorem {
+ 1..5 => foo(),
+ _ => bar,
+ }
-#### `false` (default):
+ match lorem {
+ 1..=5 => foo(),
+ _ => bar,
+ }
-```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
+ match lorem {
+ 1...5 => foo(),
+ _ => bar,
+ }
}
```
-#### `true`
+#### `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
+fn main() {
+ let lorem = 0 .. 10;
+ let ipsum = 0 ..= 10;
+
+ match lorem {
+ 1 .. 5 => foo(),
+ _ => bar,
+ }
+
+ match lorem {
+ 1 ..= 5 => foo(),
+ _ => bar,
+ }
+
+ match lorem {
+ 1 ... 5 => foo(),
+ _ => bar,
+ }
}
```
-## `wrap_comments`
+## `struct_field_align_threshold`
-Break comments to fit on the line
+The maximum diff of width between struct fields to be aligned with each other.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3347)
+- **Default value** : 0
+- **Possible values**: any non-negative integer
+- **Stable**: No (tracking issue: [#3371](https://github.com/rust-lang/rustfmt/issues/3371))
-#### `false` (default):
+#### `0` (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.
+struct Foo {
+ x: u32,
+ yy: u32,
+ zzz: u32,
+}
```
-#### `true`:
+#### `20`:
```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.
+struct Foo {
+ x: u32,
+ yy: u32,
+ zzz: u32,
+}
```
-## `match_arm_blocks`
+## `struct_lit_single_line`
-Wrap the body of arms in blocks when it does not fit on the same line with the pattern of arms
+Put small struct literals on a single line
- **Default value**: `true`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3373)
+- **Stable**: No (tracking issue: [#3357](https://github.com/rust-lang/rustfmt/issues/3357))
#### `true` (default):
```rust
fn main() {
- match lorem {
- true => {
- foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
- }
- false => println!("{}", sit),
- }
+ let lorem = Lorem { foo: bar, baz: ofo };
}
```
```rust
fn main() {
- match lorem {
- true =>
- foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
- false => println!("{}", sit),
- }
+ let lorem = Lorem {
+ foo: bar,
+ baz: ofo,
+ };
}
```
-See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
+See also: [`indent_style`](#indent_style).
-## `overflow_delimited_expr`
+## `struct_lit_width`
-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.
+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**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3370)
+- **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
-#### `false` (default):
+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.
-```rust
-fn example() {
- foo(ctx, |param| {
- action();
- foo(param)
- });
+See also [`max_width`](#max_width), [`use_small_heuristics`](#use_small_heuristics), and [`struct_lit_single_line`](#struct_lit_single_line)
- foo(
- ctx,
- Bar {
- x: value,
- y: value2,
- },
- );
+## `struct_variant_width`
- foo(
- ctx,
- &[
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ],
- );
+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`.
- foo(
- ctx,
- vec![
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ],
- );
-}
-```
+- **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
-#### `true`:
+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.
-```rust
-fn example() {
- foo(ctx, |param| {
- action();
- foo(param)
- });
+See also [`max_width`](#max_width) and [`use_small_heuristics`](#use_small_heuristics)
- foo(ctx, Bar {
- x: value,
- y: value2,
- });
+## `tab_spaces`
- foo(ctx, &[
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ]);
+Number of spaces per tab
- foo(ctx, vec![
- MAROON_TOMATOES,
- PURPLE_POTATOES,
- ORGANE_ORANGES,
- GREEN_PEARS,
- RED_APPLES,
- ]);
+- **Default value**: `4`
+- **Possible values**: any positive integer
+- **Stable**: Yes
+
+#### `4` (default):
+
+```rust
+fn lorem() {
+ let ipsum = dolor();
+ let sit = vec![
+ "amet consectetur adipiscing elit amet",
+ "consectetur adipiscing elit amet consectetur.",
+ ];
}
```
-## `blank_lines_upper_bound`
+#### `2`:
-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() {
+ let ipsum = dolor();
+ let sit = vec![
+ "amet consectetur adipiscing elit amet",
+ "consectetur adipiscing elit amet consectetur.",
+ ];
+}
+```
-- **Default value**: `1`
-- **Possible values**: any non-negative integer
-- **Stable**: No (tracking issue: #3381)
+See also: [`hard_tabs`](#hard_tabs).
-### Example
-Original Code:
-```rust
-#![rustfmt::skip]
+## `trailing_comma`
-fn foo() {
- println!("a");
-}
+How to handle trailing commas for lists
+- **Default value**: `"Vertical"`
+- **Possible values**: `"Always"`, `"Never"`, `"Vertical"`
+- **Stable**: No (tracking issue: [#3379](https://github.com/rust-lang/rustfmt/issues/3379))
+#### `"Vertical"` (default):
-fn bar() {
- println!("b");
+```rust
+fn main() {
+ let Lorem { ipsum, dolor, sit } = amet;
+ let Lorem {
+ ipsum,
+ dolor,
+ sit,
+ amet,
+ consectetur,
+ adipiscing,
+ } = elit;
+}
+```
+#### `"Always"`:
- println!("c");
+```rust
+fn main() {
+ let Lorem { ipsum, dolor, sit, } = amet;
+ let Lorem {
+ ipsum,
+ dolor,
+ sit,
+ amet,
+ consectetur,
+ adipiscing,
+ } = elit;
}
```
-#### `1` (default):
+#### `"Never"`:
+
```rust
-fn foo() {
- println!("a");
+fn main() {
+ let Lorem { ipsum, dolor, sit } = amet;
+ let Lorem {
+ ipsum,
+ dolor,
+ sit,
+ amet,
+ consectetur,
+ adipiscing
+ } = elit;
}
+```
-fn bar() {
- println!("b");
+See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
- println!("c");
+## `trailing_semicolon`
+
+Add trailing semicolon after break, continue and return
+
+- **Default value**: `true`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3378](https://github.com/rust-lang/rustfmt/issues/3378))
+
+#### `true` (default):
+```rust
+fn foo() -> usize {
+ return 0;
}
```
-#### `2`:
+#### `false`:
```rust
-fn foo() {
- println!("a");
+fn foo() -> usize {
+ return 0
}
+```
+## `type_punctuation_density`
-fn bar() {
- println!("b");
+Determines if `+` or `=` are wrapped in spaces in the punctuation of types
+- **Default value**: `"Wide"`
+- **Possible values**: `"Compressed"`, `"Wide"`
+- **Stable**: No (tracking issue: [#3364](https://github.com/rust-lang/rustfmt/issues/3364))
- println!("c");
+#### `"Wide"` (default):
+
+```rust
+fn lorem<Ipsum: Dolor + Sit = Amet>() {
+ // body
+}
+```
+
+#### `"Compressed"`:
+
+```rust
+fn lorem<Ipsum: Dolor+Sit=Amet>() {
+ // body
}
```
-See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
+## `unstable_features`
+
+Enable unstable features on the unstable channel.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3387](https://github.com/rust-lang/rustfmt/issues/3387))
-## `blank_lines_lower_bound`
+## `use_field_init_shorthand`
-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.
+Use field initialize shorthand if possible.
-- **Default value**: `0`
-- **Possible values**: *unsigned integer*
-- **Stable**: No (tracking issue: #3382)
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-### Example
-Original Code (rustfmt will not change it with the default value of `0`):
+#### `false` (default):
```rust
-#![rustfmt::skip]
-
-fn foo() {
- println!("a");
+struct Foo {
+ x: u32,
+ y: u32,
+ z: u32,
}
-fn bar() {
- println!("b");
- println!("c");
+
+fn main() {
+ let x = 1;
+ let y = 2;
+ let z = 3;
+ let a = Foo { x, y, z };
+ let b = Foo { x: x, y: y, z: z };
}
```
-#### `1`
-```rust
-fn foo() {
+#### `true`:
- println!("a");
+```rust
+struct Foo {
+ x: u32,
+ y: u32,
+ z: u32,
}
-fn bar() {
-
- println!("b");
-
- println!("c");
+fn main() {
+ let x = 1;
+ let y = 2;
+ let z = 3;
+ let a = Foo { x, y, z };
}
```
+## `use_small_heuristics`
-## `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 (tracking issue: #3386)
-
-## `hide_parse_errors`
-
-Do not show parse errors if the parser failed to parse files.
+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.
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3390)
+Note that explicitly provided values for the width configuration settings take precedence and override the calculated values determined by `use_small_heuristics`.
-## `color`
+- **Default value**: `"Default"`
+- **Possible values**: `"Default"`, `"Off"`, `"Max"`
+- **Stable**: Yes
-Whether to use colored output or not.
+#### `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`
-- **Default value**: `"Auto"`
-- **Possible values**: "Auto", "Always", "Never"
-- **Stable**: No (tracking issue: #3385)
+```rust
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit { amet: Consectetur, adipiscing: Elit },
+}
-## `unstable_features`
+fn main() {
+ lorem(
+ "lorem",
+ "ipsum",
+ "dolor",
+ "sit",
+ "amet",
+ "consectetur",
+ "adipiscing",
+ );
-Enable unstable features on the unstable channel.
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+ let lorem = Lorem { ipsum: dolor };
-- **Default value**: `false`
-- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3387)
+ let lorem = if ipsum { dolor } else { sit };
+}
+```
-## `license_template_path`
+#### `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.
-Check whether beginnings of files match a license template.
+```rust
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit {
+ amet: Consectetur,
+ adipiscing: Elit,
+ },
+}
-- **Default value**: `""`
-- **Possible values**: path to a license template file
-- **Stable**: No (tracking issue: #3352)
+fn main() {
+ lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-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.:
+ let lorem = Lorem {
+ ipsum: dolor,
+ sit: amet,
+ };
+ let lorem = if ipsum {
+ dolor
+ } else {
+ sit
+ };
+}
```
-// Copyright {\d+} The Rust Project Developers.
-```
-
-`\{`, `\}` and `\\` match literal braces / backslashes.
-## `ignore`
+#### `Max`:
+When `use_small_heuristics` is set to `Max`, then each granular width setting is set to the same value as `max_width`.
-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).
+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`
-- **Default value**: format every file
-- **Possible values**: See an example below
-- **Stable**: No (tracking issue: #3395)
+```rust
+enum Lorem {
+ Ipsum,
+ Dolor(bool),
+ Sit { amet: Consectetur, adipiscing: Elit },
+}
-### Example
+fn main() {
+ lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
-If you want to ignore specific files, put the following to your config file:
+ let lorem = Lorem { ipsum: dolor, sit: amet };
-```toml
-ignore = [
- "src/types.rs",
- "src/foo/bar.rs",
-]
+ let lorem = if ipsum { dolor } else { sit };
+}
```
-If you want to ignore every file under `examples/`, put the following to your config file:
-```toml
-ignore = [
- "examples",
-]
-```
+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)
-If you want to ignore every file under the directory where you put your rustfmt.toml:
+## `use_try_shorthand`
-```toml
-ignore = ["/"]
-```
+Replace uses of the try! macro by the ? shorthand
-## `edition`
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: Yes
-Specifies which edition is used by the parser.
+#### `false` (default):
-- **Default value**: `2015`
-- **Possible values**: `2015`, `2018`
-- **Stable**: Yes
+```rust
+fn main() {
+ let lorem = ipsum.map(|dolor| dolor.sit())?;
-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:
+ let lorem = try!(ipsum.map(|dolor| dolor.sit()));
+}
+```
-```toml
-edition = "2018"
+#### `true`:
+
+```rust
+fn main() {
+ let lorem = ipsum.map(|dolor| dolor.sit())?;
+}
```
## `version`
- **Default value**: `One`
- **Possible values**: `One`, `Two`
-- **Stable**: No (tracking issue: #3383)
+- **Stable**: No (tracking issue: [#3383](https://github.com/rust-lang/rustfmt/issues/3383))
### Example
version = "Two"
```
-## `normalize_doc_attributes`
+## `where_single_line`
-Convert `#![doc]` and `#[doc]` attributes to `//!` and `///` doc comments.
+Forces the `where` clause to be laid out on a single line.
- **Default value**: `false`
- **Possible values**: `true`, `false`
-- **Stable**: No (tracking issue: #3351)
+- **Stable**: No (tracking issue: [#3359](https://github.com/rust-lang/rustfmt/issues/3359))
#### `false` (default):
```rust
-#![doc = "Example documentation"]
-
-#[doc = "Example item documentation"]
-pub enum Foo {}
+impl<T> Lorem for T
+where
+ Option<T>: Ipsum,
+{
+ // body
+}
```
#### `true`:
```rust
-//! Example documentation
-
-/// Example item documentation
-pub enum Foo {}
+impl<T> Lorem for T
+where Option<T>: Ipsum
+{
+ // body
+}
```
-## `inline_attribute_width`
+See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
-Write an item and its attribute on the same line if their combined width is below a threshold
-- **Default value**: 0
-- **Possible values**: any positive integer
-- **Stable**: No (tracking issue: #3343)
+## `wrap_comments`
-### Example
+Break comments to fit on the line
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: [#3347](https://github.com/rust-lang/rustfmt/issues/3347))
+
+#### `false` (default):
-#### `0` (default):
```rust
-#[cfg(feature = "alloc")]
-use core::slice;
+// 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.
+
+// 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.
```
-#### `50`:
+#### `true`:
+
```rust
-#[cfg(feature = "alloc")] use core::slice;
+// 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.
```
+# Internal Options
+
## `emit_mode`
Internal option
## `make_backup`
Internal option, use `--backup`
+
+## `print_misformatted_file_names`
+
+Internal option, use `-l` or `--files-with-diff`
projects / rust.git / blobdiff