Closed
Description
Running cargo +nightly clippy on my fork.
fn pattern_to_vec(pattern: &str) -> Pattern {
pattern
.trim_matches('/')
.split('/')
.flat_map(|s| {
if let Some(idx) = s.find('.') {
vec![s[..idx].to_string(), s[idx..].to_string()]
} else {
vec![s.to_string()]
}
})
.collect::<Vec<_>>()
}The fix that is given to me for this if let Some:
warning: use Option::map_or_else instead of an if let/else
--> src/router.rs:85:17
|
85 | / if let Some(idx) = s.find('.') {
86 | | vec![s[..idx].to_string(), s[idx..].to_string()]
87 | | } else {
88 | | vec![s.to_string()]
89 | | }
| |_________________^ help: try: `s.find('.').map_or_else(|| <[_]>::into_vec(box [$($x),+]), |idx| <[_]>::into_vec(box [$($x),+]))`
|
This fix doesn't compile at all, the syntax is just borked.
The original function:
The errors given when implementing the suggestion:
The right fix: 
You can test this out on the codebase:
git clone https://github.com/sigaloid/vial
cd vial/
git checkout dfc9b61cba9436baa87931bae389e114d342437e
cargo +nightly clippy(it's the third warning from the bottom)
If I had to guess it would be something to do with the fact that it's an if statement inside of map_or_else, or maybe the vec macro?
Meta
Rust version (rustc -Vv):
rustc 1.56.1 (59eed8a2a 2021-11-01)
binary: rustc
commit-hash: 59eed8a2aac0230a8b53e89d4e99d55912ba6b35
commit-date: 2021-11-01
host: x86_64-unknown-linux-gnu
release: 1.56.1
LLVM version: 13.0.0
@rustbot label +I-suggestion-causes-error
clippy: clippy::option_if_let_else
note: the lint level is defined here
--> src/lib.rs:214:5
|
214 | clippy::nursery,
| ^^^^^^^^^^^^^^^
= note: `#[warn(clippy::option_if_let_else)]` implied by `#[warn(clippy::nursery)]`
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#option_if_let_else