fix: const fn's that don't take arguments should just be consts

Author: Lars-Schumann

src/board.rs

@@ -15,10 +15,7 @@ pub const ROW_COUNT: usize = 8;
 #[derive(Copy, Clone, PartialEq, Eq)]
 pub struct Board(pub [[Option<Piece>; ROW_COUNT]; COL_COUNT]);
 impl Board {
-    #[must_use]
-    pub const fn empty() -> Self {
-        Self([[None; ROW_COUNT]; COL_COUNT])
-    }
+    pub const EMPTY: Self = Self([[None; ROW_COUNT]; COL_COUNT]);
 
     pub(crate) fn threatening_moves_by(
         &self,
@@ -60,13 +57,11 @@ impl Board {
         self[start] = None;
     }
 
-    #[must_use]
-    pub const fn new() -> Self {
-        #[allow(clippy::wildcard_imports)]
+    pub const NEW: Self = const {
         use crate::coord::Square as S;
         use crate::piece::Piece as P;
 
-        let mut board = Self::empty();
+        let mut board = Self::EMPTY;
 
         board[S::A1] = Some(P::WHITE_ROOK);
         board[S::B1] = Some(P::WHITE_KNIGHT);
@@ -105,7 +100,7 @@ impl Board {
         board[S::H7] = Some(P::BLACK_PAWN);
 
         board
-    }
+    };
 
     #[must_use]
     pub(crate) fn piece_counts(&self) -> PieceCounts {
@@ -120,7 +115,7 @@ impl Board {
 }
 impl const Default for Board {
     fn default() -> Self {
-        Self::new()
+        Self::NEW
     }
 }
 impl const core::ops::Index<Square> for Board {

src/game.rs

@@ -147,14 +147,12 @@ impl IndexMut<Piece> for PieceCounts {
 pub struct FullMoveCount(pub NonZeroU64); // non-zero & unsigned because this always starts at 1 and cant decrease 
 impl const Default for FullMoveCount {
     fn default() -> Self {
-        Self::new()
+        Self::NEW
     }
 }
 impl FullMoveCount {
-    #[must_use]
-    pub const fn new() -> Self {
-        const { Self(NonZeroU64::new(1).expect("1 to not be 0")) }
-    }
+    pub const NEW: Self = const { Self(NonZeroU64::new(1).expect("1 to not be 0")) };
+
     pub const fn increase(&mut self) {
         self.0 = self
             .0
@@ -452,25 +450,20 @@ impl CastlingRights {
             black_queenside,
         }
     }
-    #[must_use]
-    pub const fn all_available() -> Self {
-        Self::new(
-            CastlingRight::Available,
-            CastlingRight::Available,
-            CastlingRight::Available,
-            CastlingRight::Available,
-        )
-    }
 
-    #[must_use]
-    pub const fn none_available() -> Self {
-        Self::new(
-            CastlingRight::Unavailable,
-            CastlingRight::Unavailable,
-            CastlingRight::Unavailable,
-            CastlingRight::Unavailable,
-        )
-    }
+    pub const ALL_AVAILABLE: Self = Self::new(
+        CastlingRight::Available,
+        CastlingRight::Available,
+        CastlingRight::Available,
+        CastlingRight::Available,
+    );
+
+    pub const NONE_AVAILABLE: Self = Self::new(
+        CastlingRight::Unavailable,
+        CastlingRight::Unavailable,
+        CastlingRight::Unavailable,
+        CastlingRight::Unavailable,
+    );
 
     pub const ALL: [Self; 16] = [
         Self::new(O, O, O, O),
@@ -496,7 +489,7 @@ const O: CastlingRight = CastlingRight::Unavailable;
 
 impl const Default for CastlingRights {
     fn default() -> Self {
-        Self::all_available()
+        Self::ALL_AVAILABLE
     }
 }
 

src/notation/fen.rs

@@ -133,7 +133,7 @@ impl CastlingRights {
     #[must_use]
     fn from_fen_repr(value: &[AsciiChar]) -> Self {
         if value == [AsciiChar::HyphenMinus] {
-            return Self::none_available();
+            return Self::NONE_AVAILABLE;
         }
         Self {
             white_kingside: value.contains(&AsciiChar::CapitalK).into(), // `K`
@@ -145,7 +145,7 @@ impl CastlingRights {
 
     #[must_use]
     fn to_fen_repr(self) -> Vec<AsciiChar> {
-        if self == Self::none_available() {
+        if self == Self::NONE_AVAILABLE {
             return vec![AsciiChar::HyphenMinus];
         }
         let mut out = vec![];
@@ -321,7 +321,7 @@ impl Board {
             .map(Board)
             .map_err(|_| BoardFromFenError::IllegalColDimensions)?;
 
-        let mut new_board = Self::empty();
+        let mut new_board = Self::EMPTY;
 
         //TODO: un-fuck this
         for square in Square::ALL {