On 15.05.2012 16:27, Ondrej Pokorny wrote:
On Tuesday, 15 May 2012 at 09:44:08 UTC, Jonathan M Davis wrote:
On Tuesday, May 15, 2012 11:26:49 Namespace wrote:
On Tuesday, 15 May 2012 at 09:23:51 UTC, Kagamin wrote:
> Difference with what?
> new is a safe feature: it allocates in the GC heap
That's what i mean. So i have to delete it yourself with "delete
arr;", or not?
No. _Never_ use delete. It's going to be deprecated. The GC worries about
freeing memory allocated on the GC heap, and new always allocates on
the GC
heap. If you don't want to allocate on the GC heap, then use malloc
and free,
in which case you _do_ need worry about freeing the memory.
If you need to force destruction before the GC collects an object, you
can
call clear on that object to have its destructor called and its vtbl
zeroed
out, but it's memory still isn't freed. That's the GC's job.
If you really have to, you can use core.memory to manipulate the GC heap
(including calling GC.free), but you really shouldn't be messing with
any of
that unless you really need to and you know what you're doing.
- Jonathan M Davis
Hi,
does this hold for structs too?
struct H
{
this(int a){writeln("ctor");}
~this(){writeln("dtor");}
};
...
H* h = new H(5);
clear(h);
...
output:
ctor
seems like destructor is not called.
if I change declaration of H to class H. output is following:
ctor
dtor
I tried to create object according to RAII idiom and in case of struct H
my file handle remained open and I was still able to write to file...
Ondrej
I thought in C++ RAII is about (i.e. even in C++ no heap allocation):
H h = H(5);
Same works in D. A call to clear in you code above doesn't call
destructor, it only zeros out pointer.
If you absolutely need pointers & heap and yet manual memory managment use:
clear(*h);
Explanation:
clear(x) calls x.__dtor if x is struct or class, then assigns
x = T.init;
A better way might be to just check if x.__dtor is callbale (thus
pointer to sstruct will also work).
--
Dmitry Olshansky
