c++ - 分配给指向 std::list 类型的共享指针不起作用

Question

我正在尝试将值分配给指向 std::list 的共享指针，但分配失败并给出错误，下面是我的代码供引用:

struct X
{
   public:
      X();
      X(int a,int b, std::string ss)
      {
         y=a;
         z=b;
         aa=ss;
      }

      int y;
      int z;
      std::string aa;
      typedef std::list<X> Xdata;

   private:
      friend class boost::serialization::access;
      template<class Archive>
      void serialize(Archive &at, const unsigned int version)
      {
         at & y;
         at & z;
         at & aa;
      }  
};

struct Q
{
    public:
       Q();
       std::string q1;
       boost::shared_ptr<X::Xdata> xx;

     private:
      friend class boost::serialization::access;
      template<class Archive>
      void serialize(Archive &at, const unsigned int version)
      {
         at & q1;
         at & xx;   // will this serialize ??
      } 
};


void function_assignvalue(Q *e)
{
    e->q1 = "hello";

    X datax;
    datax.y=10;
    datax.z=20;
    datax.aa="x";

    e->xx.reset(new X::Xdata());  // gives error
}

它给出了一些未解析的符号的错误并且还会 xx 序列化？

Answer 1

为您的 X 和 Q 类提供默认构造函数(参见下面的代码):

struct X
{
   public:
      X() : a(0), b(0) {}
      X(int a,int b, std::string ss) : y(a), z(b), aa(ss) {}

      int y;
      int z;
      std::string aa;
      typedef std::list<X> Xdata;

   private:
      friend class boost::serialization::access;
      template<class Archive>
      void serialize(Archive &at, const unsigned int version)
      {
         at & y;
         at & z;
         at & aa;
      }  
};

struct Q
{
    public:
       Q() {}
       std::string q1;
       boost::shared_ptr<X::Xdata> xx;

     private:
      friend class boost::serialization::access;
      template<class Archive>
      void serialize(Archive &at, const unsigned int version)
      {
         at & q1;
         at & xx;   // will this serialize ??
      } 
};