Closed
Description
Running rustfmt on this snippet of code:
pub const fn vector_width() -> usize {
#[cfg(feature="vec_width_2")]
{ 2 }
// Default
#[cfg(not(feature="vec_width_2"))]
{ 4 }
}
Rewrites it to the following, inserting two additional opening brackets {:
pub const fn vector_width() -> usize {
#[cfg(feature = "vec_width_2")]
{
{ 2
}
// Default
#[cfg(not(feature = "vec_width_2"))]
{
{ 4
}
}
To Reproduce
For a minimal working example, I created a new lib project with the following lib.rs file (gist):
pub const fn vector_width() -> usize {
#[cfg(feature="vec_width_2")]
{ 2 }
// Default
#[cfg(not(feature="vec_width_2"))]
{ 4 }
}
#[cfg(test)]
mod tests {
#[test]
fn it_works() {
assert_eq!(2 + 2, 4);
}
}
This project builds before cargo fmt but fails to build after:
fmt-bracket-bug (master) $ cargo build
Finished dev [unoptimized + debuginfo] target(s) in 0.00s
fmt-bracket-bug (master) $ cargo fmt
fmt-bracket-bug (master) $ cargo build
Compiling fmt-bracket-bug v0.1.0 (/Users/avh/research/fmt-bracket-bug)
error: this file contains an unclosed delimiter
--> src/lib.rs:19:3
|
1 | pub const fn vector_width() -> usize {
| - unclosed delimiter
2 | #[cfg(feature = "vec_width_2")]
3 | {
| - unclosed delimiter
4 | { 2
| - this delimiter might not be properly closed...
5 | }
| - ...as it matches this but it has different indentation
...
19 | }
| ^
error[E0308]: mismatched types
--> src/lib.rs:1:32
|
1 | pub const fn vector_width() -> usize {
| ------------ ^^^^^ expected `usize`, found `()`
| |
| implicitly returns `()` as its body has no tail or `return` expression
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.
error: could not compile `fmt-bracket-bug`
To learn more, run the command again with --verbose.
The following is the diff after cargo fmt
fmt-bracket-bug (master) $ git diff
diff --git a/src/lib.rs b/src/lib.rs
index d4cc40e..a790f92 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,9 +1,13 @@
pub const fn vector_width() -> usize {
- #[cfg(feature="vec_width_2")]
- { 2 }
+ #[cfg(feature = "vec_width_2")]
+ {
+ { 2
+ }
// Default
- #[cfg(not(feature="vec_width_2"))]
- { 4 }
+ #[cfg(not(feature = "vec_width_2"))]
+ {
+ { 4
+ }
}
Expected behavior
Rewrites for whitespace, without additional brackets:
pub const fn vector_width() -> usize {
#[cfg(feature = "vec_width_2")]
{
2
}
// Default
#[cfg(not(feature = "vec_width_2"))]
{
4
}
}
Meta
- rustfmt version: rustfmt 1.4.25-stable (0f29ff6 2020-11-11)
- From where did you install rustfmt?: rustup
- How do you run rustfmt:
cargo fmt