Re: Unbounded array

[Matthew Heaney <matthew_heaney@acm.org>]

Pawel Kobylarz <kobylarz@wbkst21.mach.uni-karlsruhe.de> writes:

> Realloc function takes two parameters, the actual pointer and new
> size, and it preserves the data already present in the memory block.
> Realloc is more efficient than allocate-copy-deallocate, because it
> can add a piece of memory without moving existing data if there is
> place after the existing block.

But that isn't guaranteed.  You save the cost of a copy only if there's
an adjacent block large enough to contain the new part of the array.


> In my textbook, I found only operators new and unchecked deallocation,
> nothing similar to realloc(). Is there in ADA something like
> realloc?

No, it is not built in.  However, you could

1) write a binding the C function

2) write your own storage pool that supports a realloc-style operation,
   and bind your access type to that pool; see RM95 13.11

There are open-source implementations of malloc, etc, so you should be
able to use the algorithm to implement an Ada95 version.