clear() causes crash?

[Denis Shelomovskij]

30.04.2013 1:04, "Luís Marques" <luismarques at gmail.com>" пишет:
> This crashes in the last line of main:
>
>      class A
>      {
>          void foo() {}
>      }
>
>      void main()
>      {
>          A a = new A();
>          a.foo();
>          clear(a);
>          assert(a !is null);
>          a.foo();  // crashes
>      }
>
> As far as I understand from TDPL book, this should not crash, but it
> does (DMD64 v2.062, OS X). Am I misunderstanding clear()?
>
> BTW, why not make clear also change 'a' to null?

Ideally is should throw with pretty message but it isn't implemented. 
See Issue 8139 - Make objects really disposable by addition of "Object 
finalized" assertion [1].

IMO, also `destroy` (renamed `clear`) looks like the worst mistake in D 
runtime and I'd recommend to not use it (or better recompile 
druntime+phobos without it for your own use). See Issue 9139 - `destroy` 
is dangerous and inconsistent [2]. Use 
`unstd.lifetime.finalizeClassInstance` [3] and friends for user-defined 
lifetime implementation to avoid serious problems.

[1] http://d.puremagic.com/issues/show_bug.cgi?id=8139
[2] http://d.puremagic.com/issues/show_bug.cgi?id=9139
[3] 
http://denis-sh.github.io/phobos-additions/unstd.lifetime.html#finalizeClassInstance

-- 
Денис В. Шеломовский
Denis V. Shelomovskij