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From: David Abrahams (dave_at_[hidden])
Date: 2004-02-24 03:59:10

Alberto Barbati <abarbati_at_[hidden]> writes:

> Hi Boosters,
> I had a very good time writing iterators with the new iterator_facade
> template. Very good job! It makes writing iterators so much simpler!
> What about having a similar template for allocators? Given that a
> large class of useful allocators are de facto built over a couple of
> typeless malloc-like/free-like functions, I imagine something that
> could be used like this:
> struct malloc_impl
> {
> static void* allocate(size_t n) { return malloc(n); }
> static void deallocate(void* p) { free(p); }
> };
> std::vector<int, boost::allocator_facade<int, malloc_impl> > v;
> where boost::allocator_facade<T, malloc_impl> satisfies all
> requirements that std::allocator<T> does.
> An implementation for a conforming compiler and library is
> straightforward and allocator_facade could also include workarounds
> for specific platforms where possible (for example it can easily and
> automatically provide the __stl_alloc_rebind hack in STLport).
> Is there any interest for such a thing?

My only reservation is that I don't find myself needing to make
allocators very often. In fact, the last time I wanted to make
something with an allocator interface, I found that the standard
interface wasn't appropriate for the project :(. Standard allocators
are really only good for containers, AFAICT.

Dave Abrahams
Boost Consulting

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