From f28b3a32811b0bb89a38812f7fc7bd08a97a0425 Mon Sep 17 00:00:00 2001
From: becheran <becherarmin@gmail.com>
Date: Sat, 13 Aug 2022 11:07:39 +0200
Subject: [PATCH] Speedup idx function

---
 benches/benches.rs | 10 +++++-----
 src/lib.rs         | 28 ++++++++++++++--------------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/benches/benches.rs b/benches/benches.rs
index bde95d1..04bebbb 100644
--- a/benches/benches.rs
+++ b/benches/benches.rs
@@ -83,7 +83,7 @@ fn criterion_benchmark(c: &mut Criterion) {
         b.iter_batched(
             || (rand(), rand()),
             |(x, y)| {
-                let _v = vec_vec[criterion::black_box(x)][criterion::black_box(y)];
+                let _v = vec_vec[x][y];
             },
             criterion::BatchSize::SmallInput,
         )
@@ -92,7 +92,7 @@ fn criterion_benchmark(c: &mut Criterion) {
         let grid = init_grid();
         b.iter_batched(
             || (rand(), rand()),
-            |(x, y)| grid[criterion::black_box(x)][criterion::black_box(y)],
+            |(x, y)| grid[x][y],
             criterion::BatchSize::SmallInput,
         )
     });
@@ -102,9 +102,9 @@ fn criterion_benchmark(c: &mut Criterion) {
             || (rand(), rand()),
             |(x, y)| {
                 let _v = vec_vec
-                    .get(criterion::black_box(x))
+                    .get(x)
                     .unwrap()
-                    .get(criterion::black_box(y))
+                    .get(y)
                     .unwrap();
             },
             criterion::BatchSize::SmallInput,
@@ -116,7 +116,7 @@ fn criterion_benchmark(c: &mut Criterion) {
             || (rand(), rand()),
             |(x, y)| {
                 let _v = grid
-                    .get(criterion::black_box(x), criterion::black_box(y))
+                    .get(x, y)
                     .unwrap();
             },
             criterion::BatchSize::SmallInput,
diff --git a/src/lib.rs b/src/lib.rs
index 09a4776..15a7dfa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -723,22 +723,19 @@ impl<T: Clone> Clone for Grid<T> {
 impl<T> Index<usize> for Grid<T> {
     type Output = [T];
 
-    fn index(&self, idx: usize) -> &Self::Output {
-        if idx < self.rows {
-            let start_idx = idx * self.cols;
-            &self.data[start_idx..start_idx + self.cols]
-        } else {
-            panic!(
-                "index {:?} out of bounds. Grid has {:?} rows.",
-                self.rows, idx
-            );
-        }
+    #[inline]
+    fn index(&self, idx: usize) -> &[T] {
+        let start_idx = idx * self.cols;
+        &self.data[start_idx..start_idx + self.cols]
     }
 }
 
 impl<T> IndexMut<usize> for Grid<T> {
-    fn index_mut(&mut self, idx: usize) -> &mut Self::Output {
-        &mut self.data[(idx * self.cols)..]
+    
+    #[inline]
+    fn index_mut(&mut self, idx: usize) -> &mut [T] {
+        let start_idx = idx * self.cols;
+        &mut self.data[start_idx..start_idx + self.cols]
     }
 }
 
@@ -1217,8 +1214,11 @@ mod test {
 
     #[test]
     fn idx() {
-        let grid = Grid::init(1, 2, 3);
-        assert_eq!(grid[0][0], 3);
+        let grid: Grid<u8> = Grid::from_vec(vec![1, 2, 3, 4], 2);
+        assert_eq!(grid[0][0], 1);
+        assert_eq!(grid[0][1], 2);
+        assert_eq!(grid[1][0], 3);
+        assert_eq!(grid[1][1], 4);
     }
 
     #[test]