[Move] Fix streaming with promotion

Move.cpp

@@ -1,6 +1,7 @@
 #include "Move.hpp"
 
 #include <ostream>
+#include <iostream>
 
 Move::Move(const Square &from, const Square &to, const std::optional<PieceType> &promotion)
         : mFrom(from), mTo(to), mPromotion(promotion) {
@@ -41,7 +42,7 @@ std::optional<PieceType> Move::promotion() const {
 std::ostream &operator<<(std::ostream &os, const Move &move) {
     os << move.from() << move.to();
     if (move.promotion().has_value()) {
-        os << static_cast<char>(move.promotion().value());
+        os << move.promotion().value();
     }
     return os;
 }

Piece.cpp

@@ -35,38 +35,42 @@ std::optional<PieceType> Piece::pieceTypeFromSymbol(char symbol) {
     }
 }
 
+char Piece::toSymbol() const {
+    return toSymbol(mType);
+}
+
+char Piece::toSymbol(PieceType type) {
+    switch (type) {
+    case PieceType::Pawn: return 'p';
+    case PieceType::Knight: return 'n';
+    case PieceType::Bishop: return 'b';
+    case PieceType::Rook: return 'r';
+    case PieceType::Queen: return 'q';
+    case PieceType::King: return 'k';
+    }
+
+    return '\0';
+}
+
 bool operator==(const Piece &lhs, const Piece &rhs) {
     return lhs.color() == rhs.color() && lhs.type() == rhs.type();
 }
 
 std::ostream &operator<<(std::ostream &os, const Piece &piece) {
-    int typeNum;
+    int typeNum = piece.toSymbol();
 
-    switch (piece.type()) {
+    if (piece.color() == PieceColor::White) {
-    case PieceType::Pawn: typeNum = 'P';
+        typeNum = std::toupper(typeNum);
-        break;
-    case PieceType::Knight: typeNum = 'N';
-        break;
-    case PieceType::Bishop: typeNum = 'B';
-        break;
-    case PieceType::Rook:typeNum = 'R';
-        break;
-    case PieceType::Queen: typeNum = 'Q';
-        break;
-    case PieceType::King: typeNum = 'K';
-        break;
-    default:
-        return os;
-    }
-
-    if (piece.color() == PieceColor::Black) {
-        typeNum = std::tolower(typeNum);
     }
 
     os << static_cast<char>(typeNum);
     return os;
 }
 
+std::ostream &operator<<(std::ostream &os, const PieceType &pt) {
+    return os << Piece::toSymbol(pt);
+}
+
 PieceColor operator!(PieceColor color) {
     return static_cast<PieceColor>((static_cast<int>(color) + 1) % 2);
 }

Piece.hpp

@@ -18,6 +18,8 @@ enum class PieceType {
     King
 };
 
+std::ostream &operator<<(std::ostream &os, const PieceType &pt);
+
 class Piece {
 
 public:
@@ -27,11 +29,13 @@ public:
     Piece(PieceColor color, PieceType type);
 
     static Optional fromSymbol(char symbol);
+    static char toSymbol(PieceType type);
 
     static std::optional<PieceType> pieceTypeFromSymbol(char symbol);
 
     PieceColor color() const;
     PieceType type() const;
+    char toSymbol() const;
 
 private:
     const PieceColor mColor;