typedef - does not name a type

Question

i have two headers

in header “BinTree.h":

typedef struct node {
    ElemType data;
    struct node *lchild;
    struct node *rchild;
}BTNode;

in header "Queue.h"(which includes BinTree.h):

typedef BTNode* Dataype;

at compiling the compilor said: error: ‘BTNode’ does not name a type

What's wrong?

Solution 1

Did you include BinTree.h in Queue.h before the declaration?

Or have you .cpp (or moral equivalent) include it beforehand

EDIT FOR CDT

Forward declarations are the answer.

As you did not post the code it is difficult to tell.

But I would hazzard a guess here

typedef struct node BTNode;

whould hit the ticket in Queue.h

Solution 2

If you have mutual inclusion you need a forward declaration of your node type. Add this before the typedef: typedef struct node BTnode;