Re: Ada containers and custom allocators

[Robert A Duff <bobduff@shell01.TheWorld.com>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:

> On Tue, 8 Jan 2008 17:54:44 -0600, Randy Brukardt wrote:
>
>> But it isn't valuable enough to force every user
>> of a container to define a storage pool (since there is no name for a
>> standard storage pool).
>
> That always wondered me, why there is no name for. Especially because the
> default storage pool can be obtained anyway:
>
> type Some_Ptr is access Integer; -- Goes to the default storage pool
> package Foo is new Boo (Some_Ptr'Storage_Pool);

The compiler is not required to use the same storage pool for all
types.  Therefore, the concept "THE default pool" does not exist.

Some_Ptr'Storage_Pool might be a special pool tuned for the fact that
Size_In_Storage_Elements = 4 and Alignment = 4.  Allocate could
add 4 to a known-aligned pointer, and ignore the
Size_In_Storage_Elements and Alignment parameters.

If Boo uses this pool for something other than Integer,
it might not work.

However, I see nothing wrong with having a predefined operation that
returns a suitable pool.

- Bob