'new' class method

[Yigal Chripun]

KennyTM~ wrote:
> KennyTM~ wrote:
>> Bill Baxter wrote:
>>> On Sat, Oct 25, 2008 at 2:04 AM, KennyTM~ <kennytm at gmail.com> wrote:
>>>
>>>>>  auto a = Class();  // heap   (default)
>>>>>  auto a = Struct(); // stack   (default)
>>>>>
>>>>>  auto a = Class.new(stack)(); // stack
>>>>>  auto a = Struct.new(stack)(); // stack
>>>>>
>>>>>  auto a = Class.new(heap)(); // heap
>>>>>  auto a = Struct.new(heap)(); // heap
>>>>>
>>>>>   void *addr;
>>>>>   auto a = Class.new(addr)(); // placement
>>>>>   auto a = Struct.new(addr)(); // placement
>>>>>
>>>> I strongly *oppose* using stack and heap as keywords because there
>>>> are also
>>>> (partly irrelevant) data structures called stack and heap, even though
>>>> according to the guideline these class/structs should be named Stack
>>>> and
>>>> Heap.
>>>
>>> Right, that's why both Benji and I proposed making them *context*
>>> keywords.  Just like "Windows" is a keyword only in the context of
>>> extern( ).  This would make heap and stack keywords only in the
>>> context of new(  ).
>>>
>>
>> I see. But with the your new(...) syntax this can't be done because it
>> is ambiguous with
>>
>>   void* stack = allocate();
>>   auto C = Class.new(stack)();
>>
>> The placement new syntax should use some other syntax.
>>
> 
> or do it like this:
> 
>    auto C = Class.new(placement, addr, etc)();
> //--------------------^ use this to specify it is a placement new.

maybe just add the concept of allocators.
auto C1 = Class.new(parameters/*, Allocator = GC.DefaultAllocator */);
auto C2 = Class.new(parameters, HeapAllocator); // on heap
auto C3 = Class.new(parameters, StackAllocator); // on stack
auto C4 = Class.new(parameters, MyPlacementNewAllocator);
etc..
initial Allocator hierarchy could be part of the run-time, and could be
user extended to allow for placement new.