Array of zero length

Question

I am working on refactoring some old code and have found few structs containing zero length arrays (below). Warnings depressed by pragma, of course, but I've failed to create by "new" structures containing such structures (error 2233). Array 'byData' used as pointer, but why not to use pointer instead? or array of length 1? And of course, no comments were added to make me enjoy the process... Any causes to use such thing? Any advice in refactoring those?

struct someData
{
   int nData;
   BYTE byData[0];
}

NB It's C++, Windows XP, VS 2003

Answer 1

Yes this is a C-Hack.
To create an array of any length:

struct someData* mallocSomeData(int size)
{
    struct someData*  result = (struct someData*)malloc(sizeof(struct someData) + size * sizeof(BYTE));
    if (result)
    {    result->nData = size;
    }
    return result;
}

Now you have an object of someData with an array of a specified length.