A manual memory manager for a set of mutable tuples. The point of Pool is to
allocate a single long-lived block of memory (the pool) that lives in the OCaml major
heap, and then to reuse the block, rather than continually allocating blocks on the
minor heap.
A pool stores a bounded-size set of tuples, where client code is responsible for
explicitly controlling when the pool allocates and frees tuples. One creates a pool
of a certain capacity, which returns an empty pool that can hold that many tuples.
One then uses new to allocate a tuple, which returns a Pointer.t to the tuple.
One then uses get and set along with the pointer to get and set slots of the
tuple. Finally, one free's a pointer to the pool's memory for a tuple, making the
memory available for subsequent reuse.
In typical usage, one wraps up a pool with an abstract interface, giving nice names to the tuple slots, and only exposing mutation where desired.
All the usual problems with manual memory allocation are present with pools:
There is a debugging functor, Pool.Error_check, that is useful for building pools
to help debug incorrect pointer usage.
module type Pool : sig ... end