据说是facebook笔试题，大家看看怎么做

设计一个variant类，这个类有如下特征variant v = string("jams"); //用string赋值variant v2 = 18; //用数值型赋值variant jam["name"] = v; //用variant型赋值jam["age"] = v2;jam["sex"] = string("famale");jam["hobby"] = variant.list_elem(); //“数组”型variant& hobby = jam["hobby"]; hobby[0] = string("basketball");hobby[1] = string("baseball");hobby[2] = string("classic music");const int MAGIC_NUM1 = 0x101010;const int MAGIC_NUM2 = 0x101011;hobby[3] = variant(MAGIC_NUM1);  //构造函...hobby[4] = MAGIC_NUM2;jam["address"]["state"] = string(""); // "递归"多层jam["address"]["city"] = string("");cout << jam["address"]["city"] << ", " << jam["age"] << endl;  //读取

求具体实现