如何定义包含指向本身就是一个typedef结构？ [英] How to define a typedef struct containing pointers to itself?

问题描述

我写在C链表，下面的code再present我的节点定义。

I am writing a LinkedList in C, the below code represent my Node definition.

typedef struct {
    int value;
    struct Node* next;
    struct Node* prev;
} Node;

据我所知（或认为我这样做）的结构节点同 typedef结构节点不是。当然我的code编译和运行，因为它是应该，但是，我分配接下来和 preV时<得到很多的警告/ code>（警告：从分配不兼容的指针类型）。我猜测，这与我在如何定义它们的节点结构做。
我上传的完整源这里

I understand (or think that I do) that struct Node not the same as typedef struct Node. Granted my code compiles and runs as it's supposed to, however, I get a lot of warnings when assigning next and prev (warning: assignment from incompatible pointer type). I am guessing that this has to do with how I'm defining them in the Node structure. I uploaded the full source here

所以，如果这确实是问题，应该怎么定义接下来和 $ P $光伏里面的 typedef结构节点？

So, if that is indeed the problem, how should I define next and prev inside the typedef struct Node?

我很担心这可能是一个重新发布，但不能完全找到我一直在寻找。谢谢你。

I was worried this may be a repost, but couldn't quite find what I was looking for. Thanks.

推荐答案

您需要做的是按以下顺序：

You need to do it in this order:

typedef struct Node Node;

struct Node
{
  int value;
  Node *next;
  Node *prev;
};

这不会做你问什么，但它解决了问题，就是如何这通常是完成的。我不认为有一个更好的办法。

That doesn't do exactly what you asked, but it solves the problem and is how this generally is done. I don't think there's a better way.

这种向前声明都有第二种用法，在数据隐藏。如果该列表是在一个库中实现，你可能只是在的typedef 在公共头，像函数一样：

This kind of forward declaration has a second usage, in data hiding. If the list was implemented in a library, you could have just the typedef in the public header, along with functions like:

Node * list_new(void);
Node * list_append(Node *head, Node *new_tail);
size_t list_length(const Node *head);

这样一来，图书馆的用户不容易接触到资料库的内部，即节点结构的字段。

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