Question Regarding Arrays

[Adron]

std::list works. If you have handles associated with each item and want to access them by handle you might want to use a std::map<handle,item> instead.

Example of deletion by moving things from old array to new array:

Code Select Expand


item *array;
int size;

void DeleteItem(int index)
{
  item *newarray = 0;
  if(--size) {
    int i, j;
    newarray = new item[size];
    for(i = j = 0; j < size; i++)
      if(i != index) newarray[j++] = array[i];
  }
  delete [] array;
  array = newarray;
}


[Mephisto]

If you write your own, linked lists can take a while to get right.  You might prefer to use STL - std::list is what you want, iirc. I'm not an STL person though so perhaps you should ask someone else (eibro?)

While you are correct, there are certain situations where realloc would be a good thing.  For instance, when inserting data into a buffer that may be of unknown size and you run out of room to insert data, it'd be better IMO to resize the buffer to make room then fail the operation as failing the operation may result in a terminal error (such as failing the Battle.net protocol for a bot).

[Zakath]

It's definitely worth it to learn how to make a linked list. It's an invaluable construct. I highly advise doing it that way.

[Adron]

While you are correct, there are certain situations where realloc would be a good thing.  For instance, when inserting data into a buffer that may be of unknown size and you run out of room to insert data, it'd be better IMO to resize the buffer to make room then fail the operation as failing the operation may result in a terminal error (such as failing the Battle.net protocol for a bot).

This sounds like jibberish? Did you read what everyone has been saying? Did you understand that calling "realloc" in many cases will result in a new allocation and copying of data, and that that's what we're talking about? Did anyone at any time suggest to just fail because your fixed size buffer is full?

Also, you shouldn't assume that you will be able to resize the buffer to make room. Perhaps you'll be out of memory at that time? If you want to be sure to be able to process the packets you want to process, it would actually be a very good method to preallocate a buffer of enough size to be able to hold the packets you are going to proces, and then not reallocate it at all.

[Mephisto]

While you are correct, there are certain situations where realloc would be a good thing.  For instance, when inserting data into a buffer that may be of unknown size and you run out of room to insert data, it'd be better IMO to resize the buffer to make room then fail the operation as failing the operation may result in a terminal error (such as failing the Battle.net protocol for a bot).

This sounds like jibberish? Did you read what everyone has been saying? Did you understand that calling "realloc" in many cases will result in a new allocation and copying of data, and that that's what we're talking about? Did anyone at any time suggest to just fail because your fixed size buffer is full?

Also, you shouldn't assume that you will be able to resize the buffer to make room. Perhaps you'll be out of memory at that time? If you want to be sure to be able to process the packets you want to process, it would actually be a very good method to preallocate a buffer of enough size to be able to hold the packets you are going to proces, and then not reallocate it at all.

Edit: Not even going to bother.

I'm sorry if I implied the wrong thing that upsetted you so much.   

[Dyndrilliac]

I've decided to use a linked list. Thanks guys.

[Mephisto]

I've decided to use a linked list. Thanks guys.

If you're going to be using the structure in the manner of an array a vector may be a more viable solution.  Do a search on std::vector.