Eliminate class allocators and deallocators?

[grauzone]

Andrei Alexandrescu wrote:
> Sean Kelly wrote:
>> == Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s 
>> article
>>> dsimcha wrote:
>>>> == Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s 
>>>> article
>>>>> It is a bad idea because distinguishing between release of (expensive)
>>>>> resources from dangerous memory recycling is the correct way to obtain
>>>>> deterministic resource management within the confines of safety.
>>>> This is based on two faulty assumptions:
>>>>
>>>> 1.  Memory is cheap.  (Not if you are working with absurd amounts of 
>>>> data).
>>>> 2.  Garbage collection is never a major bottleneck.  (Sometimes it's 
>>>> a worthwhile
>>>> tradeoff to add a few manual delete statements to code and sacrifice 
>>>> some safety
>>>> for making the GC run less often.)
>>> malloc.
>>
>> So for placement construction of a class, I guess it would look 
>> something like:
>>
>> auto x = cast(MyClass) malloc(MyClass.classinfo.init.length);
>> x.__ctor( a, b, c ); // construct
>> ...
>> x.__dtor();
>> free( cast(void*) x );
>>
>> Is that right?
> 
> Yes, I think so, but I haven't checked all the details. For example I'm 
> not sure whether __ctor copies .init over the memory before running the 
> user-defined constructor, or expects that to have been done already.

Apparently it doesn't: 
http://www.digitalmars.com/techtips/class_objects.html

See, it's even documented.

Anyway, does your statement mean that _ctor is officially supported (by 
all conform D compilers)?

Because, quoting from the page above:
"This technique goes "under the hood" of how D works, and as such it is 
not guaranteed to work with every D compiler. In particular, how the 
constructors and destructors are called is not necessarilly portable."