Add assignment

Piece.cpp

@@ -0,0 +1,38 @@
+#include "Piece.hpp"
+
+#include <ostream>
+
+Piece::Piece(PieceColor color, PieceType type)
+{
+    (void)color;
+    (void)type;
+}
+
+Piece::Optional Piece::fromSymbol(char symbol) {
+    (void)symbol;
+    return std::nullopt;
+}
+
+PieceColor Piece::color() const {
+    return PieceColor::Black;
+}
+
+PieceType Piece::type() const {
+    return PieceType::Pawn;
+}
+
+bool operator==(const Piece& lhs, const Piece& rhs) {
+    (void)lhs;
+    (void)rhs;
+    return false;
+}
+
+std::ostream& operator<<(std::ostream& os, const Piece& piece) {
+    (void)piece;
+    return os;
+}
+
+PieceColor operator!(PieceColor color) {
+    (void)color;
+    return PieceColor::White;
+}