3 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.
5 A possible content of `rustfmt.toml` or `.rustfmt.toml` might look like this:
9 reorder_imports = false
12 Each configuration option is either stable or unstable.
13 Stable options can be used directly, while unstable options are opt-in.
14 To enable unstable options, set `unstable_features = true` in `rustfmt.toml` or pass `--unstable-features` to rustfmt.
16 # Configuration Options
18 Below you find a detailed visual guide on all the supported configuration options of rustfmt:
23 Indent on expressions or items.
25 - **Default value**: `"Block"`
26 - **Possible values**: `"Block"`, `"Visual"`
31 #### `"Block"` (default):
51 let lorem = vec!["ipsum",
63 #### `"Block"` (default):
67 if lorem_ipsum && dolor_sit && amet_consectetur && lorem_sit && dolor_consectetur && amet_ipsum
79 if lorem_ipsum && dolor_sit && amet_consectetur && lorem_sit && dolor_consectetur && amet_ipsum
87 See also: [`control_brace_style`](#control_brace_style).
89 ### Function arguments
91 #### `"Block"` (default):
96 fn lorem(ipsum: usize) {}
116 fn lorem(ipsum: usize) {}
118 fn lorem(ipsum: usize,
131 #### `"Block"` (default):
165 #### `"Block"` (default):
173 Adipiscing: Eq = usize,
174 Consectetur: Eq = usize,
181 adipiscing: Adipiscing,
182 consectetur: Consectetur,
192 fn lorem<Ipsum: Eq = usize,
196 Adipiscing: Eq = usize,
197 Consectetur: Eq = usize,
203 adipiscing: Adipiscing,
204 consectetur: Consectetur,
213 #### `"Block"` (default):
228 let lorem = Lorem { ipsum: dolor,
233 See also: [`struct_lit_single_line`](#struct_lit_single_line), [`indent_style`](#indent_style).
237 #### `"Block"` (default):
240 fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
254 fn lorem<Ipsum, Dolor, Sit, Amet>() -> T
264 ## `use_small_heuristics`
266 Whether to use different formatting for items and expressions if they satisfy a heuristic notion of 'small'.
268 - **Default value**: `true`
269 - **Possible values**: `true`, `false`
272 #### `true` (default):
278 Sit { amet: Consectetur, adipiscing: Elit },
296 let lorem = Lorem { ipsum: dolor };
298 let lorem = if ipsum { dolor } else { sit };
315 lorem("lorem", "ipsum", "dolor", "sit", "amet", "consectetur", "adipiscing");
322 let lorem = if ipsum {
332 Where to put a binary operator when a binary expression goes multiline.
334 - **Default value**: `"Front"`
335 - **Possible values**: `"Front"`, `"Back"`
338 #### `"Front"` (default):
342 let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo
343 || barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
345 let sum = 123456789012345678901234567890 + 123456789012345678901234567890
346 + 123456789012345678901234567890;
348 let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
349 ..bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
357 let or = foofoofoofoofoofoofoofoofoofoofoofoofoofoofoofoo ||
358 barbarbarbarbarbarbarbarbarbarbarbarbarbarbarbar;
360 let sum = 123456789012345678901234567890 + 123456789012345678901234567890 +
361 123456789012345678901234567890;
363 let range = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..
364 bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb;
368 ## `combine_control_expr`
370 Combine control expressions with function calls.
372 - **Default value**: `true`
373 - **Possible values**: `true`, `false`
376 #### `true` (default):
388 foo!(if let Some(..) = x {
401 foo!(while let Some(..) = x {
435 if let Some(..) = x {
452 while let Some(..) = x {
478 Maximum length of comments. No effect unless`wrap_comments = true`.
480 - **Default value**: `80`
481 - **Possible values**: any positive integer
484 **Note:** A value of `0` results in [`wrap_comments`](#wrap_comments) being applied regardless of a line's width.
486 #### `80` (default; comments shorter than `comment_width`):
488 // Lorem ipsum dolor sit amet, consectetur adipiscing elit.
491 #### `60` (comments longer than `comment_width`):
493 // Lorem ipsum dolor sit amet,
494 // consectetur adipiscing elit.
497 See also [`wrap_comments`](#wrap_comments).
499 ## `condense_wildcard_suffixes`
501 Replace strings of _ wildcards by a single .. in tuple patterns
503 - **Default value**: `false`
504 - **Possible values**: `true`, `false`
507 #### `false` (default):
511 let (lorem, ipsum, _, _) = (1, 2, 3, 4);
512 let (lorem, ipsum, ..) = (1, 2, 3, 4);
520 let (lorem, ipsum, ..) = (1, 2, 3, 4);
524 ## `control_brace_style`
526 Brace style for control flow constructs
528 - **Default value**: `"AlwaysSameLine"`
529 - **Possible values**: `"AlwaysNextLine"`, `"AlwaysSameLine"`, `"ClosingNextLine"`
532 #### `"AlwaysSameLine"` (default):
544 #### `"AlwaysNextLine"`:
559 #### `"ClosingNextLine"`:
572 ## `disable_all_formatting`
574 Don't reformat anything
576 - **Default value**: `false`
577 - **Possible values**: `true`, `false`
580 ## `error_on_line_overflow`
582 Error if Rustfmt is unable to get all lines within `max_width`, except for comments and string
583 literals. If this happens, then it is a bug in Rustfmt. You might be able to work around the bug by
584 refactoring your code to avoid long/complex expressions, usually by extracting a local variable or
585 using a shorter name.
587 - **Default value**: `false`
588 - **Possible values**: `true`, `false`
591 See also [`max_width`](#max_width).
593 ## `error_on_unformatted`
595 Error if unable to get comments or string literals within `max_width`, or they are left with
596 trailing whitespaces.
598 - **Default value**: `false`
599 - **Possible values**: `true`, `false`
604 Argument density in functions
606 - **Default value**: `"Tall"`
607 - **Possible values**: `"Compressed"`, `"Tall"`, `"Vertical"`
610 #### `"Tall"` (default):
614 fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);
616 fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
625 consectetur: Consectetur,
626 adipiscing: Adipiscing,
635 consectetur: Consectetur,
636 adipiscing: Adipiscing,
648 fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet);
650 fn lorem(ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet) {
655 ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
656 adipiscing: Adipiscing, elit: Elit,
660 ipsum: Ipsum, dolor: Dolor, sit: Sit, amet: Amet, consectetur: Consectetur,
661 adipiscing: Adipiscing, elit: Elit,
693 consectetur: Consectetur,
694 adipiscing: Adipiscing,
703 consectetur: Consectetur,
704 adipiscing: Adipiscing,
715 Brace style for items
717 - **Default value**: `"SameLineWhere"`
718 - **Possible values**: `"AlwaysNextLine"`, `"PreferSameLine"`, `"SameLineWhere"`
723 #### `"SameLineWhere"` (default):
730 fn lorem(ipsum: usize) {
734 fn lorem<T>(ipsum: T)
736 T: Add + Sub + Mul + Div,
742 #### `"AlwaysNextLine"`:
750 fn lorem(ipsum: usize)
755 fn lorem<T>(ipsum: T)
757 T: Add + Sub + Mul + Div,
763 #### `"PreferSameLine"`:
770 fn lorem(ipsum: usize) {
774 fn lorem<T>(ipsum: T)
776 T: Add + Sub + Mul + Div, {
781 ### Structs and enums
783 #### `"SameLineWhere"` (default):
798 #### `"AlwaysNextLine"`:
814 #### `"PreferSameLine"`:
829 ## `empty_item_single_line`
831 Put empty-body functions and impls on a single line
833 - **Default value**: `true`
834 - **Possible values**: `true`, `false`
837 #### `true` (default):
855 See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
860 Put single-expression functions on a single line
862 - **Default value**: `false`
863 - **Possible values**: `true`, `false`
866 #### `false` (default):
869 fn lorem() -> usize {
873 fn lorem() -> usize {
882 fn lorem() -> usize { 42 }
884 fn lorem() -> usize {
890 See also [`control_brace_style`](#control_brace_style).
893 ## `where_single_line`
895 Forces the `where` clause to be laid out on a single line.
897 - **Default value**: `false`
898 - **Possible values**: `true`, `false`
901 #### `false` (default):
916 where Option<T>: Ipsum
922 See also [`brace_style`](#brace_style), [`control_brace_style`](#control_brace_style).
925 ## `force_explicit_abi`
927 Always print the abi for extern items
929 - **Default value**: `true`
930 - **Possible values**: `true`, `false`
933 **Note:** Non-"C" ABIs are always printed. If `false` then "C" is removed.
935 #### `true` (default):
939 pub static lorem: c_int;
947 pub static lorem: c_int;
953 Format string literals where necessary
955 - **Default value**: `false`
956 - **Possible values**: `true`, `false`
959 #### `false` (default):
964 "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet consectetur adipiscing";
972 let lorem = "ipsum dolor sit amet consectetur adipiscing elit lorem ipsum dolor sit amet \
973 consectetur adipiscing";
977 See also [`max_width`](#max_width).
981 Use tab characters for indentation, spaces for alignment
983 - **Default value**: `false`
984 - **Possible values**: `true`, `false`
987 #### `false` (default):
990 fn lorem() -> usize {
991 42 // spaces before 42
998 fn lorem() -> usize {
1003 See also: [`tab_spaces`](#tab_spaces).
1008 Indent style of imports
1010 - **Default Value**: `"Visual"`
1011 - **Possible values**: `"Block"`, `"Visual"`
1014 #### `"Visual"` (default):
1017 use foo::{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
1018 zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz};
1025 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,
1026 zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,
1030 See also: [`imports_layout`](#imports_layout).
1034 Item layout inside a imports block
1036 - **Default value**: "Mixed"
1037 - **Possible values**: "Horizontal", "HorizontalVertical", "Mixed", "Vertical"
1040 #### `"Mixed"` (default):
1043 use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
1045 use foo::{aaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd,
1046 eeeeeeeeeeeeeeeeee, ffffffffffffffffff};
1049 #### `"Horizontal"`:
1051 **Note**: This option forces all imports onto one line and may exceed `max_width`.
1054 use foo::{xxx, yyy, zzz};
1056 use foo::{aaa, bbb, ccc, ddd, eee, fff};
1059 #### `"HorizontalVertical"`:
1062 use foo::{xxxxxxxxxxxxxxxxxx, yyyyyyyyyyyyyyyyyy, zzzzzzzzzzzzzzzzzz};
1064 use foo::{aaaaaaaaaaaaaaaaaa,
1069 ffffffffffffffffff};
1089 Merge multiple imports into a single nested import.
1091 - **Default value**: `false`
1092 - **Possible values**: `true`, `false`
1095 #### `false` (default):
1106 use foo::{a, b, c, d, e, f, g};
1110 ## `match_block_trailing_comma`
1112 Put a trailing comma after a block based match arm (non-block arms are not affected)
1114 - **Default value**: `false`
1115 - **Possible values**: `true`, `false`
1118 #### `false` (default):
1126 Lorem::Dolor => println!("dolor"),
1139 Lorem::Dolor => println!("dolor"),
1144 See also: [`trailing_comma`](#trailing_comma), [`match_arm_blocks`](#match_arm_blocks).
1148 Maximum width of each line
1150 - **Default value**: `100`
1151 - **Possible values**: any positive integer
1154 See also [`error_on_line_overflow`](#error_on_line_overflow).
1158 Merge multiple derives into a single one.
1160 - **Default value**: `true`
1161 - **Possible values**: `true`, `false`
1164 #### `true` (default):
1167 #[derive(Eq, PartialEq, Debug, Copy, Clone)]
1174 #[derive(Eq, PartialEq)]
1176 #[derive(Copy, Clone)]
1180 ## `force_multiline_blocks`
1182 Force multiline closure and match arm bodies to be wrapped in a block
1184 - **Default value**: `false`
1185 - **Possible values**: `false`, `true`
1188 #### `false` (default):
1192 result.and_then(|maybe_value| match maybe_value {
1194 Some(value) => bar(),
1199 println!("Hello World");
1201 Some(dolor) => foo(),
1210 result.and_then(|maybe_value| {
1213 Some(value) => bar(),
1220 println!("Hello World");
1223 Some(dolor) => foo(),
1231 Unix or Windows line endings
1233 - **Default value**: `"Unix"`
1234 - **Possible values**: `"Native"`, `"Unix"`, `"Windows"`
1237 ## `normalize_comments`
1239 Convert /* */ comments to // comments where possible
1241 - **Default value**: `false`
1242 - **Possible values**: `true`, `false`
1245 #### `false` (default):
1249 fn dolor() -> usize {}
1252 fn adipiscing() -> usize {}
1259 fn dolor() -> usize {}
1262 fn adipiscing() -> usize {}
1266 ## `reorder_imports`
1268 Reorder import and extern crate statements alphabetically in groups (a group is
1269 separated by a newline).
1271 - **Default value**: `true`
1272 - **Possible values**: `true`, `false`
1275 #### `false` (default):
1294 ## `reorder_modules`
1296 Reorder `mod` declarations alphabetically in group.
1298 - **Default value**: `true`
1299 - **Possible values**: `true`, `false`
1302 #### `true` (default)
1326 **Note** `mod` with `#[macro_export]` will not be reordered since that could change the semantic
1327 of the original source code.
1329 ## `reorder_impl_items`
1331 Reorder impl items. `type` and `const` are put first, then macros and methods.
1333 - **Default value**: `false`
1334 - **Possible values**: `true`, `false`
1337 #### `false` (default)
1342 impl Iterator for Dummy {
1343 fn next(&mut self) -> Option<Self::Item> {
1356 impl Iterator for Dummy {
1359 fn next(&mut self) -> Option<Self::Item> {
1367 Report `TODO` items in comments.
1369 - **Default value**: `"Never"`
1370 - **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
1373 Warns about any comments containing `TODO` in them when set to `"Always"`. If
1374 it contains a `#X` (with `X` being a number) in parentheses following the
1375 `TODO`, `"Unnumbered"` will ignore it.
1377 See also [`report_fixme`](#report_fixme).
1381 Report `FIXME` items in comments.
1383 - **Default value**: `"Never"`
1384 - **Possible values**: `"Always"`, `"Unnumbered"`, `"Never"`
1387 Warns about any comments containing `FIXME` in them when set to `"Always"`. If
1388 it contains a `#X` (with `X` being a number) in parentheses following the
1389 `FIXME`, `"Unnumbered"` will ignore it.
1391 See also [`report_todo`](#report_todo).
1396 Don't reformat out of line modules
1398 - **Default value**: `false`
1399 - **Possible values**: `true`, `false`
1402 ## `space_after_colon`
1404 Leave a space after the colon.
1406 - **Default value**: `true`
1407 - **Possible values**: `true`, `false`
1410 #### `true` (default):
1413 fn lorem<T: Eq>(t: T) {
1414 let lorem: Dolor = Lorem {
1424 fn lorem<T:Eq>(t:T) {
1425 let lorem:Dolor = Lorem {
1432 See also: [`space_before_colon`](#space_before_colon).
1434 ## `space_before_colon`
1436 Leave a space before the colon.
1438 - **Default value**: `false`
1439 - **Possible values**: `true`, `false`
1442 #### `false` (default):
1445 fn lorem<T: Eq>(t: T) {
1446 let lorem: Dolor = Lorem {
1456 fn lorem<T : Eq>(t : T) {
1457 let lorem : Dolor = Lorem {
1464 See also: [`space_after_colon`](#space_after_colon).
1466 ## `struct_field_align_threshold`
1468 The maximum diff of width between struct fields to be aligned with each other.
1470 - **Default value** : 0
1471 - **Possible values**: any positive integer
1494 ## `spaces_around_ranges`
1496 Put spaces around the .., ..=, and ... range operators
1498 - **Default value**: `false`
1499 - **Possible values**: `true`, `false`
1502 #### `false` (default):
1530 let lorem = 0 .. 10;
1531 let ipsum = 0 ..= 10;
1550 ## `spaces_within_parens_and_brackets`
1552 Put spaces within non-empty generic arguments, parentheses, and square brackets
1554 - **Default value**: `false`
1555 - **Possible values**: `true`, `false`
1558 #### `false` (default):
1561 // generic arguments
1562 fn lorem<T: Eq>(t: T) {
1566 // non-empty parentheses
1567 fn lorem<T: Eq>(t: T) {
1568 let lorem = (ipsum, dolor);
1571 // non-empty square brackets
1572 fn lorem<T: Eq>(t: T) {
1573 let lorem: [usize; 2] = [ipsum, dolor];
1580 // generic arguments
1581 fn lorem< T: Eq >( t: T ) {
1585 // non-empty parentheses
1586 fn lorem< T: Eq >( t: T ) {
1587 let lorem = ( ipsum, dolor );
1590 // non-empty square brackets
1591 fn lorem< T: Eq >( t: T ) {
1592 let lorem: [ usize; 2 ] = [ ipsum, dolor ];
1596 ## `struct_lit_single_line`
1598 Put small struct literals on a single line
1600 - **Default value**: `true`
1601 - **Possible values**: `true`, `false`
1604 #### `true` (default):
1608 let lorem = Lorem { foo: bar, baz: ofo };
1623 See also: [`indent_style`](#indent_style).
1628 Number of spaces per tab
1630 - **Default value**: `4`
1631 - **Possible values**: any positive integer
1638 let ipsum = dolor();
1640 "amet consectetur adipiscing elit amet",
1641 "consectetur adipiscing elit amet consectetur.",
1650 let ipsum = dolor();
1652 "amet consectetur adipiscing elit amet",
1653 "consectetur adipiscing elit amet consectetur.",
1658 See also: [`hard_tabs`](#hard_tabs).
1663 How to handle trailing commas for lists
1665 - **Default value**: `"Vertical"`
1666 - **Possible values**: `"Always"`, `"Never"`, `"Vertical"`
1669 #### `"Vertical"` (default):
1673 let Lorem { ipsum, dolor, sit } = amet;
1689 let Lorem { ipsum, dolor, sit, } = amet;
1705 let Lorem { ipsum, dolor, sit } = amet;
1717 See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
1719 ## `trailing_semicolon`
1721 Add trailing semicolon after break, continue and return
1723 - **Default value**: `true`
1724 - **Possible values**: `true`, `false`
1727 #### `true` (default):
1741 ## `type_punctuation_density`
1743 Determines if `+` or `=` are wrapped in spaces in the punctuation of types
1745 - **Default value**: `"Wide"`
1746 - **Possible values**: `"Compressed"`, `"Wide"`
1749 #### `"Wide"` (default):
1752 fn lorem<Ipsum: Dolor + Sit = Amet>() {
1757 #### `"Compressed"`:
1760 fn lorem<Ipsum: Dolor+Sit=Amet>() {
1765 ## `use_field_init_shorthand`
1767 Use field initialize shorthand if possible.
1769 - **Default value**: `false`
1770 - **Possible values**: `true`, `false`
1773 #### `false` (default):
1786 let a = Foo { x: x, y: y, z: z };
1803 let a = Foo { x, y, z };
1807 ## `use_try_shorthand`
1809 Replace uses of the try! macro by the ? shorthand
1811 - **Default value**: `false`
1812 - **Possible values**: `true`, `false`
1815 #### `false` (default):
1819 let lorem = try!(ipsum.map(|dolor| dolor.sit()));
1827 let lorem = ipsum.map(|dolor| dolor.sit())?;
1834 Break comments to fit on the line
1836 - **Default value**: `false`
1837 - **Possible values**: `true`, `false`
1840 #### `false` (default):
1843 // 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.
1849 // Lorem ipsum dolor sit amet, consectetur adipiscing elit,
1850 // sed do eiusmod tempor incididunt ut labore et dolore
1851 // magna aliqua. Ut enim ad minim veniam, quis nostrud
1852 // exercitation ullamco laboris nisi ut aliquip ex ea
1853 // commodo consequat.
1856 ## `match_arm_blocks`
1858 Wrap the body of arms in blocks when it does not fit on the same line with the pattern of arms
1860 - **Default value**: `true`
1861 - **Possible values**: `true`, `false`
1864 #### `true` (default):
1870 foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x)
1872 false => println!("{}", sit),
1883 foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo(x),
1884 false => println!("{}", sit),
1889 See also: [`match_block_trailing_comma`](#match_block_trailing_comma).
1893 What Write Mode to use when none is supplied: Replace, Overwrite, Display, Diff, Coverage
1895 - **Default value**: `"Overwrite"`
1896 - **Possible values**: `"Checkstyle"`, `"Coverage"`, `"Diff"`, `"Display"`, `"Overwrite"`, `"Plain"`, `"Replace"`
1899 ## `blank_lines_upper_bound`
1901 Maximum number of blank lines which can be put between items. If more than this number of consecutive empty
1902 lines are found, they are trimmed down to match this integer.
1904 - **Default value**: `1`
1905 - **Possible values**: *unsigned integer*
1956 See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
1958 ## `blank_lines_lower_bound`
1960 Minimum number of blank lines which must be put between items. If two items have fewer blank lines between
1961 them, additional blank lines are inserted.
1963 - **Default value**: `0`
1964 - **Possible values**: *unsigned integer*
1968 Original Code (rustfmt will not change it with the default value of `0`):
1997 ## `remove_blank_lines_at_start_or_end_of_block`
1999 Remove blank lines at the start or the end of a block.
2001 - **Default value**: `true`
2002 - **Possible values**: `true`, `false`
2010 let mut str = String::new();
2011 str.push_str("hello, ");
2012 str.push_str("world!");
2015 println!("{}", msg);
2026 let mut str = String::new();
2027 str.push_str("hello, ");
2028 str.push_str("world!");
2032 println!("{}", msg);
2037 ## `required_version`
2039 Require a specific version of rustfmt. If you want to make sure that the
2040 specific version of rustfmt is used in your CI, use this option.
2042 - **Default value**: `CARGO_PKG_VERSION`
2043 - **Possible values**: any published version (e.g. `"0.3.8"`)
2046 ## `hide_parse_errors`
2048 Do not show parse errors if the parser failed to parse files.
2050 - **Default value**: `false`
2051 - **Possible values**: `true`, `false`
2056 Whether to use colored output or not.
2058 - **Default value**: `"Auto"`
2059 - **Possible values**: "Auto", "Always", "Never"
2062 ## `unstable_features`
2064 Enable unstable features on stable channel.
2066 - **Default value**: `false`
2067 - **Possible values**: `true`, `false`
2070 ## `license_template_path`
2072 Check whether beginnings of files match a license template.
2074 - **Default value**: `""``
2075 - **Possible values**: path to a license template file
2078 A license template is a plain text file which is matched literally against the
2079 beginning of each source file, except for `{}`-delimited blocks, which are
2080 matched as regular expressions. The following license template therefore
2081 matches strings like `// Copyright 2017 The Rust Project Developers.`, `//
2082 Copyright 2018 The Rust Project Developers.`, etc.:
2085 // Copyright {\d+} The Rust Project Developers.
2088 `\{`, `\}` and `\\` match literal braces / backslashes.
2092 Skip formatting the specified files and directories.
2094 - **Default value**: format every files
2095 - **Possible values**: See an example below
2100 If you want to ignore specific files, put the following to your config file:
2109 If you want to ignore every file under `examples/`, put the following to your config file: