• Craig Black (4/4) Mar 14 2005 How do you use new/delete instead of GC? Are you stuck using struct ins...
• Kris (6/10) Mar 14 2005 Read these:
• Andrew Fedoniouk (13/13) Mar 14 2005 Interesting question in fact.
• Derek Parnell (30/51) Mar 14 2005 Yes that's right.
• Russ Lewis (11/14) Mar 14 2005 Everything (even structs) is under control of the GC. structs will get
• Stewart Gordon (11/14) Mar 15 2005

"Craig Black" <cblack ara.com> writes:

How do you use new/delete instead of GC?  Are you stuck using struct instead 
of class?  If so, then I guess I can't define constructors when I use 
new/delete.

-Craig 

"Kris" <fu bar.com> writes:

Read these:

http://digitalmars.com/d/class.html

http://digitalmars.com/d/memory.html



"Craig Black" <cblack ara.com> wrote in message
news:d158e8$2s78$1 digitaldaemon.com...
 How do you use new/delete instead of GC?  Are you stuck using struct

instead
 of class?  If so, then I guess I can't define constructors when I use
 new/delete.

 -Craig

"Andrew Fedoniouk" <news terrainformatica.com> writes:

Interesting question in fact.

This way it should work:

MyClass c = new MyClass();
delete c;

class instances are the heap beasts.

structs in D are 'primitive' types ( int, double, etc. )
E.g. to *allocate* an int you need to do int* myintptr = new int;
And to delete - delete myintptr;

Same for structures:

struct MyStruct { ... }

MyStruct *pms = new MyStruct;
delete pms;

I am not sure though :)

Derek Parnell <derek psych.ward> writes:

On Mon, 14 Mar 2005 16:47:06 -0800, Andrew Fedoniouk wrote:

 Interesting question in fact.
 
 This way it should work:
 
 MyClass c = new MyClass();
 delete c;
 
 class instances are the heap beasts.
 
 structs in D are 'primitive' types ( int, double, etc. )
 E.g. to *allocate* an int you need to do int* myintptr = new int;
 And to delete - delete myintptr;
 
 Same for structures:
 
 struct MyStruct { ... }
 
 MyStruct *pms = new MyStruct;
 delete pms;
 
 I am not sure though :)

Yes that's right.
<code>
import std.stdio;
struct S
{
    real r;
}

void main()
{
    int* x;
    
    S* y;
    
    x = new int;
    
    y = new S;
    
    *x = 4;
    y.r = 5.6;
    
    writefln("x = %d, y = %f", *x, y.r);
    delete x;    
    delete y;
}
</code>

-- 
Derek
Melbourne, Australia
15/03/2005 11:58:48 AM

Russ Lewis <spamhole-2001-07-16 deming-os.org> writes:

Craig Black wrote:
 How do you use new/delete instead of GC?  Are you stuck using struct instead 
 of class?  If so, then I guess I can't define constructors when I use 
 new/delete.

Everything (even structs) is under control of the GC.  structs will get 
cleaned up like everything else, when there are no references to them. 
Likewise with anything else allocated with new, such as arrays or 
individual ints.

However, you can explicitly delete anything, if you want; but you are 
responsible for making sure that the thing you are deleting hasn't 
already been collected by the GC, and that you never use it again.

If you want the GC to not collect your data, then you have two choices:
1) use malloc/free
2) Keep a reference to the thing

Stewart Gordon <smjg_1998 yahoo.com> writes:

Russ Lewis wrote:
<snip>
 However, you can explicitly delete anything, if you want; but you are 
 responsible for making sure that the thing you are deleting hasn't 
 already been collected by the GC, and that you never use it again.

<snip>

If you still have a reference to the thing in order to delete it, of 
course it won't be collected by the GC.  Of course you could (for the 
time being) use the tricks it tells you not to to hide the pointer from 
the GC, but what would be the point?

Stewart.

-- 
My e-mail is valid but not my primary mailbox.  Please keep replies on 
the 'group where everyone may benefit.