On Fri, 09 Oct 2009 22:01:30 +0300, Andrei Alexandrescu
<seewebsiteforem...@erdani.org> wrote:
Andrei Alexandrescu wrote:
Jacob Carlborg wrote:
On 10/9/09 18:40, Andrei Alexandrescu wrote:
I'm talking with Sean and Walter about taking the first step towards
eliminating delete: defining function clear() that clears the state of
an object. Let me know of what you think.
One problem I encountered is that I can't distinguish between a
default
constructor that doesn't need to exist, and one that was disabled
because of other constructors. Consider:
class A {}
class B { this(int) {} }
You can evaluate "new A" but not "new B". So it's legit to create
objects of type A all default-initialized. But the pointer to
constructor stored in A.classinfo is null, same as B.
Any ideas?
Andrei
How about this:
static if (is(typeof({
auto t = new T;
})))
I'm in awe. Thanks, Jacob!!!
Andrei
Oh, wait, that doesn't work:
class A {}
class B : A { this(int) {} }
A a = new B;
clear(a); // oops
From what I understand, if you need to be able to look at derived classes,
then this information can only be stored in the ClassInfo - but, as you
have already pointed out, defaultConstructor is only set for explicit
constructors. Therefore you'll need some kind of new flag, which indicates
whether the class only has non-default constructors.
P.S. I hope that by "eliminating delete" you mean obsoleting it, and not
actually taking it out of the language :)
--
Best regards,
Vladimir mailto:thecybersha...@gmail.com
