“'struct <anonymous>”没有名为

Question

寻找引用节点的方法，并将其设置为创建函数的null。来自给定输出的任何建议将队列中的前节点和后节点设置为NULL？

gcc -std=c99 -ggdb -Wall -Wextra  -c queueADT.c
queueADT.c:13:1: warning: useless storage class specifier in empty declaration [enabled by default]
 };
 ^
queueADT.c: In function 'que_create':
queueADT.c:36:6: error: 'struct <anonymous>' has no member named 'front'
   new->front = NULL;
      ^
queueADT.c:37:6: error: 'struct <anonymous>' has no member named 'rear'
   new->rear = NULL;
      ^
queueADT.c:38:8: error: expected identifier before '*' token
   new->*cmprFunc = NULL;

以下是导致错误的代码的主要部分。(2个结构)

typedef struct node {
    void* data;
    //size_t num;
    struct node *next;
};


struct QueueADT {
    struct node front;                     /* pointer to front of queue */
    struct node rear;                      /* pointer to rear of queue  */
    int *contents[ QUEUE_SIZE ];      /* number of items in queue  */
    int *cmprFunc;                    /* The compare function used for insert */
};


#include "queueADT.h"


/// create a queue that is either sorted by cmp or FIFO
//function with two void
QueueADT que_create( int (*cmp)(const void*a,const void*b) ) {

    QueueADT new;
    new = (QueueADT)malloc(sizeof(struct QueueADT));

    if (cmp == NULL) {
        //do I create a new pointer to the cmp_int64?
        new->front = NULL;
        new->rear = NULL;
        new->*cmprFunc = NULL;

    } else {
        new->*cmprFunc = &cmp;
        new->front = NULL;
        new->rear = NULL;
    }

    return ( new );
}

Answer 1

这在我看来是无效的：

    struct QueueADT new;
    new = (QueueADT)malloc(sizeof(struct QueueADT));

    if (cmp == NULL) {
        //do I create a new pointer to the cmp_int64?
        new->front = NULL;
        ...

也许你需要这个：

    struct QueueADT *new;
    new = (struct QueueADT*)malloc(sizeof(struct QueueADT));

    if (cmp == NULL) {
        //do I create a new pointer to the cmp_int64?
        new->front = NULL;
        ...

和

struct QueueADT {
    struct node front;                     /* pointer to front of queue */
    struct node rear;                      /* pointer to rear of queue  */
    int *contents[ QUEUE_SIZE ];      /* number of items in queue  */
    int *cmprFunc;                    /* The compare function used for insert */
};

可能应该是

struct QueueADT {
    struct node *front;                     /* pointer to front of queue */
    struct node *rear;                      /* pointer to rear of queue  */
    int *contents[ QUEUE_SIZE ];      /* number of items in queue  */
    int *cmprFunc;                    /* The compare function used for insert */
};

和这里的typedef是没有意义的，应该删除它：

typedef struct node {
    void* data;
    //size_t num;
    struct node *next;
};

其他问题：struct QueueADT中的这两个声明在我看来很可疑：

    int *contents[ QUEUE_SIZE ];      /* number of items in queue  */
    int *cmprFunc;                    /* The compare function used for insert */

Answer 2

删除从typedef struct node {..

• Change typedef到

1. typedef struct QueueADT {//body}; be QueueADT *new;

以此类推..