Question

I am writing a code where I have to add a value to an abstract data table, but I am not sure why I cannot as it shows “error C2106: ‘=’ : left operand must be l-value” error.

int top_add(top_string *table, const char index[257], const char other[257]) {

    top_remove(&table, index);

    if (table->item_count == table->size) {
        printf("/n Table is full.");
        return -1;
    }

    /* error C2106: '=' : left operand must be l-value */
    table->item[table->item_count].index = index; 

    /*error C2106: '=' : left operand must be l-value */
    table->item[table->item_count].other = other;

    table->item_count++;

    return 1;
}

I did some search online, but could not find too relative solution for me.

I would really appreciate any hint on that.

UPDATE:

typedef struct {
    char index[257];
    char other[257];
} pair;


typedef struct {
    pair *item;
    int item_count;
    int size;
} top_string;

int top_init(top_string *table, const int size) {

    table->item = malloc((size+1)*sizeof(top_string));
    table->size = size;
    table->item_count = 0;

    if (table->item == NULL) {
        return 0; /* failed to allocate memory */
    } else {
        return 1;
    }

}

Answer 1

The fields index and other are arrays, you can’t assign arrays. You’d have to copy them with memcpy.

Another option would to have top_add receive pair instead of the two separately. Then you could assign the struct.