未定义类型的使用无效 - C.

Question

鉴于以下内容: -

#include <stdlib.h>
#include <stdio.h>
#include "SOM.h"
int N = 10;
int FEATURES = 5;

struct _Node{
  int x, y;
  double w[];
};

struct Node **nodes;

void main(){
  init();
}

void init(){
  int i, j;
  Node tmp;
  nodes = malloc(N * sizeof(Node*));
  for(i=0; i<N; i++){
    nodes[i] = malloc(N * (2*sizeof(int) + FEATURES*sizeof(double)));
    for(j=0; j<N; j++){
      nodes[i][j]->x = i; //Troublesome line
      nodes[i][j]->y = j; //Troublesome line
      nodes[i][j]->w = {0.0, 0.1}; //Troublesome line
    }
  }
}

void clean(){
  //
}

标题: -

#ifndef SOM
#define SOM
typedef struct _Node Node;

void init();
void clean();

#endif

我在编译时收到以下内容: -

SOM.c: In function ‘init’:
SOM.c:25:7: error: invalid use of undefined type ‘struct Node’
SOM.c:25:15: error: dereferencing pointer to incomplete type
SOM.c:26:7: error: invalid use of undefined type ‘struct Node’
SOM.c:26:15: error: dereferencing pointer to incomplete type
SOM.c:27:7: error: invalid use of undefined type ‘struct Node’
SOM.c:27:15: error: dereferencing pointer to incomplete type
SOM.c:27:24: error: expected expression before ‘{’ token

但是,我(据我所知)定义了_Node结构并给它起了假名Node.我想我误解了这个错误.有人能够解释什么是错的.我本身并不是在寻找代码修复,而是更多地解释了我出错的地方.

问候

Answer 1

这条线错了:

struct Node **nodes;

它需要是:

Node **nodes;

要么:

struct _Node **nodes;

但不是两者的混合物,正如你现在所拥有的那样.