Declaration rule in struct typedef

Question

I\'m reading \'The C Programming Language\' and encountered a problem about typedef of struct. The code is like this:

typedef struct tnode *         


        

Answer 1

A line typedef struct tnode *Treeptr; has implicit forward declaration of "tnode" struct. It's similar to:

typedef struct tnode Treenode;
typedef Treenode *Treeptr;

struct tnode { /* the tree node: */
    char *word; /* points to the text */
    int count; /* number of occurrences */
    struct tnode *left; /* left child */
    struct tnode *right; /* right child */
};