[bitboard] Remove #[must_use] from method calls; add it to BitBoard type

bitboard/src/bitboard.rs

@@ -30,12 +30,12 @@ const SQUARES_NUM: u8 = Square::NUM as u8;
 ///      A  B  C  D  E  F  G  H
 /// ```
 ///
+#[must_use]
 #[derive(Clone, Copy, Eq, Hash, PartialEq)]
 pub struct BitBoard(pub(crate) u64);
 
 macro_rules! moves_getter {
     ($getter_name:ident) => {
-        #[must_use]
         pub fn $getter_name(sq: Square) -> BitBoard {
             library::library().$getter_name(sq)
         }
@@ -46,44 +46,38 @@ impl BitBoard {
     const EMPTY: BitBoard = BitBoard(u64::MIN);
     const FULL: BitBoard = BitBoard(u64::MAX);
 
-    #[must_use]
     pub const fn empty() -> BitBoard {
         Self::EMPTY
     }
 
-    #[must_use]
     pub const fn full() -> BitBoard {
         Self::FULL
     }
 
-    #[must_use]
     pub const fn new(bits: u64) -> BitBoard {
         BitBoard(bits)
     }
 
-    #[must_use]
+    // TODO: Is &u8 really necessary here?
     pub fn rank(rank: &u8) -> BitBoard {
         debug_assert!(*rank < 8);
         library::RANKS[*rank as usize]
     }
 
-    #[must_use]
+    // TODO: Is &u8 really necessary here?
     pub fn file(file: &u8) -> BitBoard {
         debug_assert!(*file < 8);
         library::FILES[*file as usize]
     }
 
-    #[must_use]
     pub fn ray(sq: Square, dir: Direction) -> BitBoard {
         library::library().ray(sq, dir)
     }
 
-    #[must_use]
     pub fn pawn_attacks(sq: Square, color: Color) -> BitBoard {
         library::library().pawn_attacks(sq, color)
     }
 
-    #[must_use]
     pub fn pawn_pushes(sq: Square, color: Color) -> BitBoard {
         library::library().pawn_pushes(sq, color)
     }
@@ -94,12 +88,10 @@ impl BitBoard {
     moves_getter!(queen_moves);
     moves_getter!(king_moves);
 
-    #[must_use]
     pub const fn kingside(color: Color) -> &'static BitBoard {
         &library::KINGSIDES[color as usize]
     }
 
-    #[must_use]
     pub const fn queenside(color: Color) -> &'static BitBoard {
         &library::QUEENSIDES[color as usize]
     }
@@ -243,10 +235,12 @@ impl BitBoard {
         }
     }
 
+    #[must_use]
     pub fn occupied_squares_leading(&self) -> LeadingBitScanner {
         LeadingBitScanner::new(self.0)
     }
 
+    #[must_use]
     pub fn occupied_squares_trailing(&self) -> TrailingBitScanner {
         TrailingBitScanner::new(self.0)
     }