Re: Weird controlled behavior - Gnat 3.15p NT

[Hyman Rosen <hyrosen@mail.com>]

Dmitry A. Kazakov wrote:
> You might say that the above is rubbish. Not at all. It is a design
> pattern for self-destructing objects.

Not at all. It's a well-known and good pattern, as you say.

> Now imagine what should happen if somebody would allocate
> Foo on the stack?

Undefined behavior. You are not allowed to do that, and if you do,
the behavior of the program is unspecifed by the language. (The
workaround is to make the destructor protected, by the way. Then the
compiler will prevent such objects from being allocated on the stack,
because the destructor will be inaccessible.)

If you call a destructor yourself, you must make sure that the
compiler will not call the destructor again on that object (which in
fact no longer exists, except as a region of storage with undefined
contents).