-`cargo fmt` uses `--write-mode=overwrite` by default.
-
-If you want to restrict reformatting to specific sets of lines, you can
-use the `--file-lines` option. Its argument is a JSON array of objects
-with `file` and `range` properties, where `file` is a file name, and
-`range` is an array representing a range of lines like `[7,13]`. Ranges
-are 1-based and inclusive of both end points. Specifying an empty array
-will result in no files being formatted. For example,
-
-```
-rustfmt --file-lines '[
- {"file":"src/lib.rs","range":[7,13]},
- {"file":"src/lib.rs","range":[21,29]},
- {"file":"src/foo.rs","range":[10,11]},
- {"file":"src/foo.rs","range":[15,15]}]'
-```
-
-would format lines `7-13` and `21-29` of `src/lib.rs`, and lines `10-11`,
-and `15` of `src/foo.rs`. No other files would be formatted, even if they
-are included as out of line modules from `src/lib.rs`.
-
-If `rustfmt` successfully reformatted the code it will exit with `0` exit
-status. Exit status `1` signals some unexpected error, like an unknown option or
-a failure to read a file. Exit status `2` is returned if there are syntax errors
-in the input files. `rustfmt` can't format syntactically invalid code. Finally,
-exit status `3` is returned if there are some issues which can't be resolved
-automatically. For example, if you have a very long comment line `rustfmt`
-doesn't split it. Instead it prints a warning and exits with `3`.
-
-You can run `rustfmt --help` for more information.