C++ Struct - Error 1 error C2143: syntax error : missing ';' before '*'

Question

when i try to compile the following, i receive the error "Error 1 error C2143: syntax error : missing ';' before '*'". Does anyone know why am i receiving this error? What am i doing wrong here?

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>
};

You need your declarations in the opposite order. `HE_edge` tries to use `HE_vert`, which the compiler doesn't know about yet. — BoBTFish, Oct 09 '13 at 08:30
ho forward declaration of you types ? So HE_vert does not name a type in the definition of HE_edge. A lot of compiler tell you this now, apparently not yours. — Jaffa, Oct 09 '13 at 08:30
In fact, I didn't immediately realise you have a circular dependency. Look at [forward declarations](http://stackoverflow.com/q/553682/1171191). — BoBTFish, Oct 09 '13 at 08:32

score 4 · Accepted Answer · answered Oct 09 '13 at 08:33

Try to declare your structs in the right order : Since HE_edge depends on HE_vert and HE_face, declare them before.

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>
};

score 2 · Answer 2 · edited May 23 '17 at 12:28

2

You need to forward declare HE_vert and HE_face before you use them in HE_edge.

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

struct HE_edge { /* as before */ };

See When to use forward declaration?

edited May 23 '17 at 12:28

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answered Oct 09 '13 at 08:30

juanchopanza

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score 1 · Answer 3 · answered Oct 09 '13 at 08:30

1

You need to declare all the classes before you use their types to make pointers:

struct HE_edge;
struct HE_vert;
struct HE_face;

// your code

answered Oct 09 '13 at 08:30

Kerrek SB

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score 1 · Answer 4 · answered Oct 09 '13 at 08:30

1

You must declare identifiers before you use them. For structures this is simply done by e.g.

struct HE_vert;

Place that before the definition of HE_edge.

answered Oct 09 '13 at 08:30

Some programmer dude

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score 1 · Answer 5 · answered Oct 09 '13 at 08:32

The first declaration has no idea what HE_vert and HE_face is, to you need to tell the compiler what are those:

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>
};

Razvan.

C++ Struct - Error 1 error C2143: syntax error : missing ';' before '*'

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