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Description
Hello,
I was using clippy to check some code I wrote for advent of code 2018 and I believe I have a false positive for if_same_then_else.
The piece of code I get the error for:
use std::collections::HashSet;
fn main() {
let text = "x\ny\n";
let mut clays = HashSet::new();
for line in text.lines() {
let (from, to, p) = (10, 20, 10);
if line.starts_with('x') {
let x = p;
for y in from..=to {
clays.insert((x, y));
}
} else if line.starts_with('y') {
let y = p;
for x in from..=to {
clays.insert((x, y));
}
}
}
}
cargo clippy output:
$ cargo clippy (master ?)
Checking cl v0.1.0 (/tmp/cl)
error: this `if` has identical blocks
--> src/main.rs:15:41
|
15 | } else if line.starts_with('y') {
| _________________________________________^
16 | | let y = p;
17 | | for x in from..=to {
18 | | clays.insert((x, y));
19 | | }
20 | | }
| |_________^
|
= note: #[deny(clippy::if_same_then_else)] on by default
note: same as this
--> src/main.rs:10:34
|
10 | if line.starts_with('x') {
| __________________________________^
11 | | let x = p;
12 | | for y in from..=to {
13 | | clays.insert((x, y));
14 | | }
15 | | } else if line.starts_with('y') {
| |_________^
= help: for further information visit https://rust-lang-nursery.github.io/rust-clippy/master/index.html#if_same_then_else
error: aborting due to previous error
error: Could not compile `cl`.
In the code it either iterates fromfrom to to for x or y while p determines the stationary point. The blocks actually have different outcomes.
cargo clippy -V output:
$ cargo clippy -V (master ?)
clippy 0.0.212 (2e26fdc 2018-11-22)
The same error is reported on the version on Rust Playground:
Playground Link