Question

当我尝试编译以下内容时，我收到错误＆＃34;错误1错误C2143：语法错误：丢失＆＃39 ;;＆＃39;之前＆＃39; *＆＃39;＆＃34;。有谁知道为什么我收到这个错误？我在这做错了什么？

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

尝试以正确的顺序声明您的结构：由于HE_edge依赖于HE_vert和HE_face，因此请在之前声明它们。

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HE_vert中使用之前，您需要转发声明HE_face和HE_edge。

// 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

在使用类型生成指针之前，需要声明所有类：

struct HE_edge;
struct HE_vert;
struct HE_face;

// your code

Answer 4

在使用之前，您必须声明标识符。对于结构，这只是通过例如

完成的

struct HE_vert;

将其放在HE_edge的定义之前。

Answer 5

第一个声明不知道HE_vert和HE_face是什么，你需要告诉编译器那是什么：

struct HE_face;
struct HE_vert;//tell compiler what are HE_vert and 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>
};

勒兹。

C ++ Struct - 错误1错误C2143：语法错误：缺少';'在'*'之前

5 个答案: