move get_index to misc.rs

src/repr/board.rs

@@ -1,5 +1,6 @@
 use super::{
     bitboard::BitBoard,
+    misc::get_index,
     misc::{diag_raw, split_from},
     piece::Piece,
 };
@@ -20,10 +21,6 @@ type ChainCollection = ArrayVec<Chain, 8>;
 pub struct PosMap<T: Default>(ArrayVec<T, { Board::BOARD_AREA }>);
 
 impl<T: Default> PosMap<T> {
-    const fn index(row: usize, col: usize) -> usize {
-        row * Board::BOARD_SIZE + col
-    }
-
     #[allow(clippy::new_without_default)]
     pub fn new() -> Self {
         Self(ArrayVec::from_iter(
@@ -32,7 +29,7 @@ impl<T: Default> PosMap<T> {
     }
 
     pub fn get(&self, row: usize, col: usize) -> &T {
-        let index = Self::index(row, col);
+        let index = get_index(row, col);
 
         debug_assert!(
             Board::BOARD_AREA + 1 >= index,
@@ -44,7 +41,7 @@ impl<T: Default> PosMap<T> {
     }
 
     pub fn set(&mut self, row: usize, col: usize, value: T) {
-        let index = Self::index(row, col);
+        let index = get_index(row, col);
         debug_assert!(
             Board::BOARD_AREA + 1 >= index,
             "index out of range, was: {}",