feat(game): add operator< for Card

src/game/Card.cpp

@@ -68,4 +68,11 @@ namespace UNO::GAME {
         }
         return std::format("{} {}", this->colorToString(), this->typeToString());
     }
+
+    bool Card::operator<(const Card &other) const {
+        if (this->color_ != other.color_) {
+            return this->color_ < other.color_;
+        }
+        return this->type_ < other.type_;
+    }
 }

src/game/Card.h

@@ -81,6 +81,11 @@ namespace UNO::GAME {
          * @return 卡牌对应的显示字符串
          */
         [[nodiscard]] std::string toString() const;
+
+        /**
+         * 比较运算符，用于排序
+         */
+        bool operator<(const Card &other) const;
     };
 }   // namespace UNO::GAME