• Benji Smith <dlanguage benjismith.net> Oct 18 2008
• John Reimer <terminal.node gmail.com> Oct 18 2008
• "Jarrett Billingsley" <jarrett.billingsley gmail.com> Oct 18 2008
• Benji Smith <dlanguage benjismith.net> Oct 19 2008
• Lars Kyllingstad <public kyllingen.NOSPAMnet> Oct 19 2008
• Benji Smith <dlanguage benjismith.net> Oct 19 2008

Benji Smith <dlanguage benjismith.net> writes:

Looking at the official docs, I can't find the D1 syntax for forcing a 
struct to be allocated on the heap (so that it can safely be returned 
from a function). I'm pretty sure it's possible (without wrapping the 
struct in a class or an array), but I can't for the life of me remember 
how it's done.

Thanks for your help!

--benji

John Reimer <terminal.node gmail.com> writes:

Hello Benji,

 Looking at the official docs, I can't find the D1 syntax for forcing a
 struct to be allocated on the heap (so that it can safely be returned
 from a function). I'm pretty sure it's possible (without wrapping the
 struct in a class or an array), but I can't for the life of me
 remember how it's done.
 
 Thanks for your help!
 
 --benji
 



Doesn't this work?

-----------------------------
struct sample { int a; int b; }

auto s = new sample;
-----------------------------

or even the long way, following the example of D custom class allocators 
(from D language manual):

----------------------------
struct sample
{
int a;
int b;
}

sample* p;

p = std.c.stdlib.malloc(sample.sizeof);
if (!p)
throw new OutOfMemoryException();
std.gc.addRange(p, p + sample.sizeof);
----------------------------------------

-JJR

"Jarrett Billingsley" <jarrett.billingsley gmail.com> writes:

On Sun, Oct 19, 2008 at 12:25 AM, Benji Smith <dlanguage benjismith.net> wrote:
 Looking at the official docs, I can't find the D1 syntax for forcing a
 struct to be allocated on the heap (so that it can safely be returned from a
 function). I'm pretty sure it's possible (without wrapping the struct in a
 class or an array), but I can't for the life of me remember how it's done.


..you can always safely return a struct from a function, unless of
course it has members that point onto the stack.

Benji Smith <dlanguage benjismith.net> writes:

Jarrett Billingsley wrote:
 On Sun, Oct 19, 2008 at 12:25 AM, Benji Smith <dlanguage benjismith.net> wrote:
 Looking at the official docs, I can't find the D1 syntax for forcing a
 struct to be allocated on the heap (so that it can safely be returned from a
 function). I'm pretty sure it's possible (without wrapping the struct in a
 class or an array), but I can't for the life of me remember how it's done.


 ..you can always safely return a struct from a function, unless of
 course it has members that point onto the stack.


Oops. I meant to say that I need to return a struct *POINTER* from a 
function. In which case, I think I need to force heap allocation.

Thanks!

--benji

Lars Kyllingstad <public kyllingen.NOSPAMnet> writes:

Benji Smith wrote:
 Looking at the official docs, I can't find the D1 syntax for forcing a 
 struct to be allocated on the heap (so that it can safely be returned 
 from a function). I'm pretty sure it's possible (without wrapping the 
 struct in a class or an array), but I can't for the life of me remember 
 how it's done.
 
 Thanks for your help!
 
 --benji


You allocate a struct on the heap using the "new" keyword.

   struct Foo { ... }
   Foo* foo = new Foo;

Note that "new" returns a pointer for non-object types.

-Lars

Benji Smith <dlanguage benjismith.net> writes:

Lars Kyllingstad wrote:
 You allocate a struct on the heap using the "new" keyword.
 
   struct Foo { ... }
   Foo* foo = new Foo;
 
 Note that "new" returns a pointer for non-object types.



Perfect. Thanks!

--benji