new constructors

src/board.rs

@@ -110,6 +110,17 @@ impl File {
         ]
     }
 
+    #[inline]
+    pub fn new(index: u8) -> Option<Self> {
+        (index < 8).then(|| unsafe { Self::new_unchecked(index) })
+    }
+
+    #[inline]
+    pub unsafe fn new_unchecked(index: u8) -> Self {
+        debug_assert!(index < 8);
+        std::mem::transmute(index)
+    }
+
     #[inline]
     pub fn to_char(self) -> char {
         self.to_ascii() as char
@@ -128,7 +139,10 @@ impl File {
     #[inline]
     pub(crate) fn from_ascii(c: u8) -> Option<Self> {
         (c <= b'h')
-            .then(|| c.checked_sub(b'a').map(|i| unsafe { Self::transmute(i) }))
+            .then(|| {
+                c.checked_sub(b'a')
+                    .map(|i| unsafe { Self::new_unchecked(i) })
+            })
             .flatten()
     }
 
@@ -136,12 +150,6 @@ impl File {
     pub(crate) fn bitboard(self) -> Bitboard {
         Bitboard(0x0101010101010101 << (self as u8))
     }
-
-    #[inline]
-    pub(crate) unsafe fn transmute(value: u8) -> Self {
-        debug_assert!(value < 8);
-        std::mem::transmute(value)
-    }
 }
 
 impl std::fmt::Display for File {
@@ -182,6 +190,17 @@ impl Rank {
         ]
     }
 
+    #[inline]
+    pub fn new(index: u8) -> Option<Self> {
+        (index < 8).then(|| unsafe { Self::new_unchecked(index) })
+    }
+
+    #[inline]
+    pub unsafe fn new_unchecked(index: u8) -> Self {
+        debug_assert!(index < 8);
+        std::mem::transmute(index)
+    }
+
     #[inline]
     pub fn to_char(self) -> char {
         self.to_ascii() as char
@@ -194,7 +213,7 @@ impl Rank {
 
     #[inline]
     pub fn mirror(self) -> Self {
-        unsafe { Self::transmute(7_u8.unchecked_sub(self as u8)) }
+        unsafe { Self::new_unchecked(7_u8.unchecked_sub(self as u8)) }
     }
 
     #[inline]
@@ -205,19 +224,16 @@ impl Rank {
     #[inline]
     pub(crate) fn from_ascii(c: u8) -> Option<Self> {
         (c <= b'8')
-            .then(|| c.checked_sub(b'1').map(|i| unsafe { Self::transmute(i) }))
+            .then(|| {
+                c.checked_sub(b'1')
+                    .map(|i| unsafe { Self::new_unchecked(i) })
+            })
             .flatten()
     }
 
     #[inline]
     pub(crate) fn bitboard(self) -> Bitboard {
-        Bitboard(0xFF << ((self as u64) << 3))
-    }
-
-    #[inline]
-    pub(crate) unsafe fn transmute(value: u8) -> Self {
-        debug_assert!(value < 8);
-        std::mem::transmute(value)
+        Bitboard(0xFF << ((self as u8) << 3))
     }
 }
 
@@ -262,23 +278,34 @@ impl Square {
     }
 
     #[inline]
-    pub fn new(file: File, rank: Rank) -> Self {
-        unsafe { Self::transmute(((rank as u8) << 3) | file as u8) }
+    pub fn new(index: u8) -> Option<Self> {
+        (index < 64).then(|| unsafe { Self::new_unchecked(index) })
+    }
+
+    #[inline]
+    pub unsafe fn new_unchecked(index: u8) -> Self {
+        debug_assert!(index < 64);
+        std::mem::transmute(index)
+    }
+
+    #[inline]
+    pub fn from_coords(file: File, rank: Rank) -> Self {
+        unsafe { Self::new_unchecked(((rank as u8) << 3) | file as u8) }
     }
 
     #[inline]
     pub fn file(self) -> File {
-        unsafe { File::transmute((self as u8) & 7) }
+        unsafe { File::new_unchecked((self as u8) & 7) }
     }
 
     #[inline]
     pub fn rank(self) -> Rank {
-        unsafe { Rank::transmute((self as u8) >> 3) }
+        unsafe { Rank::new_unchecked((self as u8) >> 3) }
     }
 
     #[inline]
     pub fn mirror(self) -> Self {
-        Self::new(self.file(), self.rank().mirror())
+        Self::from_coords(self.file(), self.rank().mirror())
     }
 
     #[inline]
@@ -312,7 +339,10 @@ impl Square {
     #[inline]
     pub(crate) fn from_ascii(s: &[u8; 2]) -> Option<Self> {
         let [f, r] = *s;
-        Some(Self::new(File::from_ascii(f)?, Rank::from_ascii(r)?))
+        Some(Self::from_coords(
+            File::from_ascii(f)?,
+            Rank::from_ascii(r)?,
+        ))
     }
 
     #[inline]
@@ -329,7 +359,7 @@ impl Square {
         debug_assert!(self.check_trans(direction));
         let i = self as u8;
         unsafe {
-            Self::transmute(match direction {
+            Self::new_unchecked(match direction {
                 Direction::East => i.unchecked_add(1),
                 Direction::NorthEast => i.unchecked_add(9),
                 Direction::North => i.unchecked_add(8),
@@ -356,12 +386,6 @@ impl Square {
             Direction::West => self.file() > File::A,
         }
     }
-
-    #[inline]
-    pub(crate) unsafe fn transmute(value: u8) -> Self {
-        debug_assert!(value < 64);
-        std::mem::transmute(value)
-    }
 }
 
 impl std::fmt::Display for Square {
@@ -419,7 +443,7 @@ impl OptionSquare {
         unsafe {
             match self {
                 Self::None => None,
-                _ => Some(Square::transmute(self as u8)),
+                _ => Some(Square::new_unchecked(self as u8)),
             }
         }
     }