C循环依赖 [英] C circular dependency

问题描述

我在 C 中遇到循环依赖的问题，我查看了有关此主题的其他问题，但实际上找不到答案。

I have this problem with circular dependency in C, I looked around the other questions about this topic but really couldn't find the answer.

我有第一个名为vertex的结构：

I have this first struct named vertex:

#ifndef MapTest_vertex_h
#define MapTest_vertex_h

#include "edgelist.h" //includes edgelist because it's needed

typedef struct 
{
    char* name;
    float x, y;
    edgelist* edges;
} vertex;

#endif

第二个结构是边缘列表，包含在vertex。

The second struct is the edgelist which is included by the vertex.

#ifndef edgelist_h
#define edgelist_h

#include "edge.h" //include edge, because its needed

typedef struct _edgelist
{
    edge** edges; 
    int capacity, size;
} edgelist;

//...

#endif

然后是最后一个结构，即问题引发的结构，边结构包含在上面的边缘列表中。

And then the last struct, the one where the problem raises, the edge struct gets included by the edgelist above.

#ifndef MapTest_edge_h
#define MapTest_edge_h

#include "vertex.h" //needs to be included because it will be unkown otherwise

typedef struct 
{
    float weight;
    vertex* destination;
    int found; 
} edge;

#endif

我尽我所能，转发声明，使用 #ifndef ， #define 等，但找不到答案。

I tried everything I could, forward declaring, using #ifndef, #define etc. but couldn't find the answer.

如何解决这个循环依赖问题？

How can I resolve this circular dependency problem?

推荐答案

似乎就像你不应该在任何文件中包含任何内容。相关类型的远期声明应该足够：

Seems like you shouldn't need to include anything in any of the files. A forward declaration of the relevant types should be sufficient:

#ifndef MapTest_vertex_h
#define MapTest_vertex_h

struct edgelist;

typedef struct
{
    char* name;
    float x, y;
    edgelist* edges;    // C++ only - not C
} vertex;

#endif

等。在C编码中，你必须写：

etc. In C coding, you have to write:

struct edgelist;

typedef struct
{
    char* name;
    float x, y;
    struct edgelist* edges;
} vertex;

这篇关于C循环依赖的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！