[feat][struct_pack] not support shared_ptr

[manuel76413]

I saw the struct_pack library supports many STL containers
but after testing, I regretted that this library does not support the smart point of C++ 11.
like shared_ptr etc.

for example, I have a tree node struct like:

enum class type_e {
root = 0,
users = 1,
projs = 2,
};

struct Node {
type_e type;
std::string name;
std::string value;
std::list<std::shared_ptr<Node>> children;
};

for now, this library cannot serialize/deserialize the above Node structure.
you can reference another nonintrusive library named alpaca, which supports smart point.

[poor-circle]

Thank you. It's in my todolist.

[poor-circle]

But, in this case, the shared_ptr is unnecessary.

[poor-circle]

If you don't want to shared the nodes, just remove the shared_ptr.

enum class type_e {
root = 0,
users = 1,
projs = 2,
};

struct Node {
type_e type;
std::string name;
std::string value;
std::list<Node> children;
};

Serialize/deserilaize shared_ptr will cost additional price. First we need check if the address is same as previous one to shared the object. Second deserialize shared_ptr may cause memory leak and we need to check it. Anyway I will try to support it later.

[manuel76413]

thanks for your reply, This library is very cute

[982945902]

shared_ptr可能会导致循环引用问题，这个不是很好解决吧

[poor-circle]

shared_ptr可能会导致循环引用问题，这个不是很好解决吧

1. 首先在编译期检查类型是否成环。只有类型系统成环才可能出现循环引用。
2. 类型成环的情况下，要么禁止序列化这种类型，要么在反序列化时跑下dfs检测是否循环引用。

[982945902]

shared_ptr可能会导致循环引用问题，这个不是很好解决吧

1. 首先在编译期检查类型是否成环。只有类型系统成环才可能出现循环引用。
2. 类型成环的情况下，要么禁止序列化这种类型，要么在反序列化时跑下dfs检测是否循环引用。
   soga