Add assignment

PrincipalVariation.hpp

@@ -0,0 +1,25 @@
+#ifndef CHESS_ENGINE_PRINCIPALVARIATION_HPP
+#define CHESS_ENGINE_PRINCIPALVARIATION_HPP
+
+#include "Move.hpp"
+#include "Piece.hpp"
+
+#include <iosfwd>
+#include <cstddef>
+
+class PrincipalVariation {
+public:
+
+    using MoveIter = Move*;
+
+    bool isMate() const;
+    int score() const;
+
+    std::size_t length() const;
+    MoveIter begin() const;
+    MoveIter end() const;
+};
+
+std::ostream& operator<<(std::ostream& os, const PrincipalVariation& pv);
+
+#endif