+/// Score struct keeps a midgame and an endgame value in a single
+/// ScoreValue 64 bit union.
+
+union ScoreValue {
+ int64_t v64;
+ struct {
+ int32_t mgv;
+ int32_t egv;
+ } v32;
+};
+
+struct Score {
+
+ Score() {}
+ Score(const Score& s) { v = s.v; }
+ Score(int mg, int eg) { v.v32.mgv = int32_t(mg); v.v32.egv = int32_t(eg); }
+
+ Score& operator=(const Score& s) { v = s.v; return *this; }
+ Score& operator+=(const Score& s) { v.v32.mgv += s.v.v32.mgv; v.v32.egv += s.v.v32.egv; return *this; }
+ Score& operator-=(const Score& s) { v.v32.mgv -= s.v.v32.mgv; v.v32.egv -= s.v.v32.egv; return *this; }
+
+ bool operator==(const Score& s) { return v.v64 == s.v.v64; }
+ bool operator!=(const Score& s) { return v.v64 != s.v.v64; }
+
+ Value mg() const { return Value(v.v32.mgv); }
+ Value eg() const { return Value(v.v32.egv); }
+
+private:
+ ScoreValue v;
+};
+
+inline Score operator+(Score s1, Score s2) { return Score(s1.mg() + s2.mg(), s1.eg() + s2.eg()); }
+inline Score operator-(Score s1, Score s2) { return Score(s1.mg() - s2.mg(), s1.eg() - s2.eg()); }
+inline Score operator*(Score s1, Score s2) { return Score(s1.mg() * s2.mg(), s1.eg() * s2.eg()); }
+inline Score operator*(int i, Score s) { return Score(i * s.mg(), i * s.eg()); }
+inline Score operator*(Score s, int i) { return Score(s.mg() * i, s.eg() * i); }
+inline Score operator/(Score s, int i) { return Score(s.mg() / i, s.eg() / i); }
+inline Score operator-(Score s) { return Score(-s.mg(), -s.eg()); }
+
+extern std::ostream& operator<<(std::ostream& os, Score s);
+