abuse a nighly feature instead of a dependency

Cargo.lock

@@ -5,21 +5,3 @@ version = 3
 [[package]]
 name = "aoc2022"
 version = "0.1.0"
-dependencies = [
- "itertools",
-]
-
-[[package]]
-name = "either"
-version = "1.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90e5c1c8368803113bf0c9584fc495a58b86dc8a29edbf8fe877d21d9507e797"
-
-[[package]]
-name = "itertools"
-version = "0.10.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
-dependencies = [
- "either",
-]

Cargo.toml

@@ -6,4 +6,3 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-itertools = "0.10.5"

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"

src/day03.rs

@@ -1,5 +1,3 @@
-use itertools::Itertools;
-
 pub fn process_part_1(input: &str) -> u32 {
     input
         .lines()
@@ -23,16 +21,11 @@ pub fn process_part_1(input: &str) -> u32 {
 pub fn process_part_2(input: &str) -> u32 {
     let result = input
         .lines()
-        .chunks(3)
-        .into_iter()
-        .map(|chunk| {
-            let lines: Vec<_> = chunk
-                .map(|l| l.chars().unique().collect::<Vec<_>>())
-                .collect();
-
-            let overlap = *lines[0]
-                .iter()
-                .find(|c| lines[1].contains(*c) && lines[2].contains(*c))
+        .array_chunks::<3>()
+        .map(|[a, b, c]| {
+            let overlap = a
+                .chars()
+                .find(|chr| b.contains(*chr) && c.contains(*chr))
                 .unwrap();
 
             match overlap {

src/lib.rs

@@ -1,3 +1,4 @@
+#![feature(iter_array_chunks)]
 extern crate core;
 
 pub mod day01;