Boost logo

Boost :

Subject: Re: [boost] ASIO into the standard
From: Niall Douglas (s_sourceforge_at_[hidden])
Date: 2014-07-11 05:44:22


On 10 Jul 2014 at 23:48, Felipe Magno de Almeida wrote:

> > Nor are allocators consistently used for internals of STL containers.
> > They have to be used for the type being stored of course, but
> > internal data structures not exposed to external code may use any
> > allocator e.g. malloc().
>
> I thought this only applied to non-templated-on-allocator types.
> For example, list must use the allocator passed, rebound of course,
> to allocate its node. Or am I completely mistaken?
> If so then allocators are just fairy tale.

Of course it must. But if some implementation of list decided to keep
some internal housekeeping data, it could use malloc or any other
kind of allocator. For example some debug enhanced implementations
keep additional debug info.

The concurrent_unordered_map I am currently experimenting with uses
the externally supplied allocator to allocate the value_type, but
uses the default allocator for the bucket allocation. I believe this
is permitted.

Niall

-- 
ned Productions Limited Consulting
http://www.nedproductions.biz/ 
http://ie.linkedin.com/in/nialldouglas/



Boost list run by bdawes at acm.org, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk