class PartDescription
{
public:
   PartDescription(String part_name,
      int inventory_number);
private:
   const String name;
   const int part_number:
   vector<PartDescription*> subcomponents;
};
PartDescription::PartDescription(String part_name,
      int inventory_number)
   : name(part_name), part_number(inventory_number),
      subcomponents(3) {}