C++结构-错误1错误C2143:语法错误:缺失';‘在'*’之前

Question

当我试图编译以下内容时，我会收到错误"Error 1 error C2143:语法错误:缺失';‘前面'*'“。有人知道我为什么会收到这个错误吗？我在这里做错什么了？

struct HE_edge {
HE_vert* vert; // vertex at the end of the half-edge<br>
HE_edge* pair; // oppositely oriented half-edge<br>
HE_face* face; // the incident face<br>
HE_edge* prev; // previous half-edge around the face<br>
HE_edge* next; // next half-edge around the face<br>
};

struct HE_vert {
float x, y, z; // the vertex coordinates<br>
HE_edge* edge; // one of the half-edges emanating from the vertex<br>
};

struct HE_face {
HE_edge* edge; // one of the half-edges bordering the face<br>
};

Answer 1

尝试按照正确的顺序声明您的结构:因为HE_edge依赖于HE_vert和HE_face，所以在前面声明它们。

struct HE_vert;
struct HE_face;

struct HE_edge {
HE_vert* vert; // vertex at the end of the half-edge<br>
HE_edge* pair; // oppositely oriented half-edge<br>
HE_face* face; // the incident face<br>
HE_edge* prev; // previous half-edge around the face<br>
HE_edge* next; // next half-edge around the face<br>
};

struct HE_vert {
float x, y, z; // the vertex coordinates<br>
HE_edge* edge; // one of the half-edges emanating from the vertex<br>
};

struct HE_face {
HE_edge* edge; // one of the half-edges bordering the face<br>
};

Answer 2

在使用HE_vert和HE_face之前，您需要转发声明它们。

// fwd declarations. Can use "struct" or "class" interchangeably.
struct HE_vert;
struct HE_face;

struct HE_edge { /* as before */ };

请参阅When to use forward declaration?

Answer 3

在使用类类型创建指针之前，需要声明所有类：

struct HE_edge;
struct HE_vert;
struct HE_face;

// your code