From 07a1391030bf4aed845edb75d8f1c26f7c5705be Mon Sep 17 00:00:00 2001
From: Xiretza <xiretza@xiretza.xyz>
Date: Thu, 9 Dec 2021 21:26:36 +0100
Subject: [PATCH] 2021 day8/rust: make v4 function unsafe

---
 2021/day8/day8_rs/benches/unscramble.rs | 2 +-
 2021/day8/day8_rs/src/v4.rs             | 2 +-
 2021/day8/day8_rs/tests/unscramble.rs   | 6 +++++-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/2021/day8/day8_rs/benches/unscramble.rs b/2021/day8/day8_rs/benches/unscramble.rs
index fe1b3d3..335a1f3 100644
--- a/2021/day8/day8_rs/benches/unscramble.rs
+++ b/2021/day8/day8_rs/benches/unscramble.rs
@@ -36,7 +36,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
     group.bench_function("v4", |b| {
         b.iter(|| {
             for line in &lines {
-                let _ = v4::unscramble(black_box(line));
+                let _ = unsafe { v4::unscramble(black_box(line)) };
             }
         })
     });
diff --git a/2021/day8/day8_rs/src/v4.rs b/2021/day8/day8_rs/src/v4.rs
index 76bd80a..89ec18f 100644
--- a/2021/day8/day8_rs/src/v4.rs
+++ b/2021/day8/day8_rs/src/v4.rs
@@ -17,7 +17,7 @@ const FREQ_TABLE: [usize; 256] = {
 
 #[must_use]
 #[inline]
-pub fn unscramble(line: &str) -> LineResult {
+pub unsafe fn unscramble(line: &str) -> LineResult {
     let mut bytes = line.bytes();
 
     let mut counts = [0; 7];
diff --git a/2021/day8/day8_rs/tests/unscramble.rs b/2021/day8/day8_rs/tests/unscramble.rs
index 1070a6a..5688005 100644
--- a/2021/day8/day8_rs/tests/unscramble.rs
+++ b/2021/day8/day8_rs/tests/unscramble.rs
@@ -73,5 +73,9 @@ pub fn test_unscramble_v3() {
 
 #[test]
 pub fn test_unscramble_v4() {
-    test_unscramble(v4::unscramble)
+    fn safe_v4(input: &str) -> LineResult {
+        unsafe { v4::unscramble(input) }
+    }
+
+    test_unscramble(safe_v4)
 }