我或多或少使用C中的指针，所以抱歉，如果我犯了一些可怕的错误！在这种情况下，我只是试图将浮动矢量的所有元素复制到另一个元素中。
我的 main.c 文件中有以下代码块，工作正常：
/* NOTE: hash_list is a global variable*/
void insertDataIntoOurHashList(int dia, int delay, char *aeO, char *aeD){
unsigned int numHash;
ListData *listData;
numHash = getHashValue(aeO);
/* If there's no list yet in this position, then... */
if (hash_list[numHash] == NULL) {
hash_list[numHash] = malloc(sizeof(List));
initList(hash_list[numHash]);
listData = malloc(sizeof(ListData));
listData->key = malloc(sizeof(char*)*strlen(aeD)+1);
strcpy(listData->key, aeD);
listData->key_sec = malloc(sizeof(char*)*strlen(aeO)+1);
strcpy(listData->key_sec, aeO);
listData->numTimes = 1;
listData->retrasos = (float*) malloc(sizeof(float)*7);
listData->retrasos[dia-1] = delay;
insertList(hash_list[numHash], listData);
}
else {
listData = findList2(hash_list[numHash],aeD,aeO);
/* If already exists a data with both equals keys, then... */
if (listData != NULL) {
listData->numTimes++; // We add in one the counter of the list
listData->retrasos[dia-1] = listData->retrasos[dia-1] + delay / 2;
}
/* If exists a data with the same aeD as primary key but not with the aeO as secundary key, then... */
else {
listData = malloc(sizeof(ListData));
listData->key = malloc(sizeof(char*)*strlen(aeD)+1);
strcpy(listData->key, aeD);
listData->key_sec = malloc(sizeof(char*)*strlen(aeO)+1);
strcpy(listData->key_sec, aeO);
listData->numTimes = 1;
listData->retrasos = (float*) malloc(sizeof(float)*7);
listData->retrasos[dia-1] = delay;
insertList(hash_list[numHash], listData);
}
}
free(aeO);
free(aeD);
}
ListData * listData 是指向我 linked-list.h 中定义的结构的指针文件， _hash_list _ 是 列表 类型的指针向量，其中每个指向 列表<的列表/ em> ，在同一个文件中定义：
/**
*
* The TYPE_LIST_KEY is used to define the type of the primary
* key used to index data in the list.
*
*/
#define TYPE_LIST_KEY char*
/**
*
* This structure holds the information to be stored at each list item. Change
* this structure according to your needs. In order to make this library work,
* you also need to adapt the functions compEQ and freeListData. For the
* current implementation the "key" member is used search within the list.
*
*/
typedef struct ListData_ {
// The variable used to index the list has to be called "key".
TYPE_LIST_KEY key;
char *key_sec;
// This is the additional information that will be stored
// within the structure. This additional information is associated
// to the key. You may include any field you may need useful.
float *retrasos;
int numTimes;
} ListData;
/**
*
* The item structure
*
*/
typedef struct ListItem_ {
ListData *data;
struct ListItem_ *next;
} ListItem;
/**
*
* The list structure
*
*/
typedef struct List_ {
int numItems;
ListItem *first;
} List;
然后，回到我的 main.c 文件中，我遍历 _hash_list _ 中的每个单元格，传递指针的那个指针单元格指向一个从列表中获取数据并将它们传递给另一个函数的函数，我的意思是：
void insertInHash(){
int i;
for(i = 0; i < HASH_SIZE; i++){
if (hash_list[i] != NULL) {
dumpList2(hash_list[i]);
}
}
}
/* This function is called for every cell while looping the hash_list */
void dumpList2(List *l){
ListItem *current;
current = l->first;
while (current != NULL)
{
insertDataIntoOurTree(current->data->key_sec, current->data->key, current->data->retrasos);
current = current->next;
}
}
void insertDataIntoOurTree(char *aeO, char *aeD, float *delays){
List *list;
ListData *listData;
int i;
/* Case when the node exists! */
if (treeData != NULL) {
treeData->num++; // We add in one the counter of treeData
listData = findList(treeData->list, aeD); // We check if the new destination airport is inside the list of the node...
/* If the destination is inside the list... */
if(listData != NULL)
listData->numTimes++; // We add in one the counter of the list
/* If the destination isn't inside... */
else {
/* We create and initialize the new item the list of the node will contain! */
listData = malloc(sizeof(ListData));
listData->key = malloc(sizeof(char*)*strlen(aeD)+1); // Counting with the final '\0' byte!
strcpy(listData->key, aeD); // Remember the case as above with aeO and aeD
listData->numTimes = 1;
listData->retrasos = (float*) malloc(sizeof(float)*7);
//listData->retrasos[dia-1] = delay; // minus one cos we don't want to be out of bound! ;)
//copyDelays(listData->retrasos, delays);
for (i = 0; i < 7; i++) {
listData->retrasos[i] = 0.0;
}
copyDelays(listData->retrasos, delays);
insertList(treeData->list, listData);
}
}
/* THERE ARE MORE CASES DOWN HERE, BUT THEY DON'T MATTER NOW... */
}
copyDelays 功能在我的 linked-list.c 文件中定义：
void copyDelays(float *delaysToCopy, float *delays){
int i;
for (i = 0; i < 7; i++) {
if (delaysToCopy[i] == 0.0) {
memcpy(delaysToCopy[i], delays[i], sizeof(float));
}
}
}
最后，当我尝试编译所有文件时，我得到了这个我不明白的错误：
linked-list.c:234:14: error: passing 'float' to parameter of incompatible type 'const void *'
memcpy(delaysToCopy[i], delays[i], sizeof(float*));
^~~~~~~~~~~~~~~
/usr/include/secure/_string.h:65:59: note: expanded from macro 'memcpy'
__builtin___memcpy_chk (dest, src, len, __darwin_obsz0 (dest))
^~~~
/usr/include/secure/_common.h:38:55: note: expanded from macro '__darwin_obsz0'
#define __darwin_obsz0(object) __builtin_object_size (object, 0)
^~~~~~
1 error generated.
make: *** [linked-list.o] Error 1
答案 0 :(得分：1)
问题是你传递给memcpy（）函数的参数与函数的签名不匹配。 memcpy（）函数签名如下：（http://www.cplusplus.com/reference/cstring/memcpy/）
void * memcpy ( void * destination, const void * source, size_t num );
如您所见，它将指针作为第一个和第二个参数，而delaysToCopy[i]和delays[i]不是指针，只是浮动。
如果您使用＆符号来获取地址，它应该可以解决您的问题，如下所示：
memcpy(&delaysToCopy[i], &delays[i], sizeof(float));