why allocators are not discussed here

[Adam D. Ruppe]

I was just quickly skimming some criticism of C++ allocators, 
since my thought here is similar to what they do. On one hand, 
maybe D can do it right by tweaking C++'s design rather than 
discarding it.

On the other hand, with all the C++ I've done, I have never 
actually used STL allocators, which could say something about me 
or could say something about them.


One thing I saw said making the differently allocated object a 
different type sucks. ...but must it? The complaint there was "so 
much for just doing a function that takes a std::string". But, 
the way I'd want to do it in D is the function would take a 
char[] instead, and our special allocated type provides that via 
opSlice and/or alias this.

So you'd only have to worry about the different type if you 
intend to take ownership of the container yourself. Which we 
already kinda think about in D: if you store a char[], someone 
else could overwrite it, so we prefer to store an 
immutable(char)[] aka string. If you're given a char[] and want 
to store it, you might idup. So I don't think doing a private 
copy with some other allocation scheme is any more of a hassle.

(BTW immutable objects IMO should *always* be garbage collected, 
because part of immutability is infinite lifetime. So we might 
want to be careful with implicit conversions to immutable based 
on allocation method, which I believe we can protect through 
member functions.)


Anyway, bottom line is I don't think that criticism necessarily 
applies to D. But there's surely many others and I'm more or less 
a n00b re c++'s allocators so idk yet.