Are D classes always garbage collected?

[Ali Çehreli]

On 12/21/2011 10:20 PM, Froglegs wrote:
 >
 >>> Which returned me a nice fat null pointer.. wth? Perhaps that should
 >>> be a compile time error if you aren't supposed to use classes..
 >>
 >> Strange... I'm not sure what the deal is with that overload. I meant
 >> the last one on the page (that takes a void[]).
 >
 >
 > Hum I've tried the array version but I believe it contains a rather
 > serious bug...
 >
 > T emplace(T, Args...)(void[] chunk, Args args) if (is(T == class))
 > {
 > enforce(chunk.length >= __traits(classInstanceSize, T),
 > new ConvException("emplace: chunk size too small"));
 > ...
 >
 > This fails whenever the size is greater or equal to the amount of memory
 > required :(

That bug has recently been fixed:

   http://d.puremagic.com/issues/show_bug.cgi?id=6204

 > Anyway I need the pointer version for what I was hoping to do, unless
 > there is some way to convert a pointer into an array?

emplace() with classes is a little more involved compared to structs; I 
think because the type of the class variable need not be the same type 
as the instance.

 > Is there any way to do something like this..
 >
 > void* pData = some_c_function();
 > void [] fakeArray = pData, size;

Yes, as Andrew Wiley has shown:

   void[] fakeArray = pData[0..size];

Ali

P.S. I have all of this in my Turkish book but that chapter hasn't been 
translated to English yet:

   http://ddili.org/ders/d/bellek_yonetimi.html