[board, moves] Derive Clone on several error types

- PlacePieceError
- MakeMoveError
- UnmakeMoveError

board/src/piece_sets.rs

@@ -21,7 +21,7 @@ pub enum PlacePieceStrategy {
     PreserveExisting,
 }
 
-#[derive(Debug, Error, Eq, PartialEq)]
+#[derive(Clone, Debug, Error, Eq, PartialEq)]
 pub enum PlacePieceError {
     #[error("cannot place piece on {square} with existing {piece}")]
     ExisitingPiece { piece: Piece, square: Square },

moves/src/make_move.rs

@@ -18,7 +18,7 @@ pub enum ValidateMove {
     Yes,
 }
 
-#[derive(Debug, Error, Eq, PartialEq)]
+#[derive(Clone, Debug, Error, Eq, PartialEq)]
 pub enum MakeMoveError {
     #[error("no piece on {0}")]
     NoPiece(Square),

moves/src/unmake_move.rs

@@ -7,7 +7,7 @@ use thiserror::Error;
 
 pub type UnmakeMoveResult = Result<(), UnmakeMoveError>;
 
-#[derive(Debug, Error, Eq, PartialEq)]
+#[derive(Clone, Debug, Error, Eq, PartialEq)]
 pub enum UnmakeMoveError {
     #[error("no move to unmake")]
     NoMove,