Re: Prohibiting dynamic allocation for the given type

[gpriv@axonx.com]

On Mar 18, 5:30 pm, Maciej Sobczak <see.my.homep...@gmail.com> wrote:
> Is it possible to "prohibit" dynamic allocation for the given type?
>
> Let's suppose that I have a type which instances make sense only on
> the stack.

Ada is high level language and stack is implementation specific
entity. ARM does not mention how the local objects are allocated (it
simply irrelevant).  In fact, GNAT uses two stacks for different type
of objects but users don't have to know these details.

> I want to prohibit users from dynamically allocating
> instances of this type so that they don't get into troubles.
> Preferably at compile-time.

What's wrong with good old comments atop of type declaration. Like
some beverages have: "for most enjoyment serve chilled" or "for best
performance avoid heap allocation".

Don't know if it's ever possible to do it during compile, nothings
comes to my mind. But if you insist you may do run-time check by
defining custom Storage_Pool pool for your object and raising
exception from Allocate method. See ARM 3.11 for details.

G.

>
> My understanding is that it cannot be done (allocation is not
> considered to be a type's operation and there is no way to "hide" it
> from users - as is possible in C++), but I would like to have it
> confirmed.
>
> --
> Maciej Sobczak *www.msobczak.com*www.inspirel.com