Nathan, Eljay, Lyle- Thanks for your responses. > >>you asked for an array of Bs, if you're not treating it as an array of > >>Bs it's not gonna work. As far as I know, I can do new B[10]; and store it in any pointer type. For example: char *ptr = (char *) new B[10]; C *ptr = (C *) new C[10]; No problem unless I try to dereference ptr, then I will get the wrong data. But I take the true size of one array element into account and always cast back to a A * before dereferencing an array element. I don't see this as lying to the compiler, just a clever use of casting and walking an array. I used to do a lot of video coding and we did that all the time, casting video memory between char * and long * and what not. The memory remains the same, we just look at it in a different way. But let's say I take your suggestion and implement an array of pointers. How do I allocate the memory for 10 Bs in one block? I don't want 10 separate instances of B, I want a contiguous block of 10 Bs. I could create a block of 10 Bs: B *block = new B[10]; and then an array of pointers: A **ptrarray = new A *[10]; and then point the elements in the array to the block-- for (int i = 0; i < 10; i++) ptrarray[i] = &block[i]; // Or block+i, whichever you prefer But then how would I delete the block? I would still have to do: delete[] block; and I can't do this because in my code the memory manager (base class) does not know about the derived classes. delete[] only appears to work when the pointer type matches the actual type allocated-- in contrast to 'delete', which works regardless. Kind Regards, -Mercury
