Re: [Boost-users] Is there a boost equivalent of eastl::fixed_vector?

Subject: Re: [Boost-users] Is there a boost equivalent of eastl::fixed_vector?
From: Matthias Troyer (troyer_at_[hidden])
Date: 2008-09-24 05:47:14

On Sep 24, 2008, at 11:32 AM, dariomt_at_[hidden] wrote:

> In EASTL http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2271.html 
>  there is something like SSO (Small String Optimization) applied to  
> std::vector (and other STL containers)
>
> [begin quote]
> "Fixed containers are fixed-size containers with their memory stored  
> right within the container itself. Fixed containers allocate no  
> dynamic memory and their memory tends to be cache-friendly due to  
> its contiguity and proximity to the container's housekeeping data.  
> The user declares the max container size as a template parameter,  
> and can also specify that if the container overflows that an  
> auxiliary dynamic allocator is used.
>
> template <typename T, size_t nodeCount, bool enableOverflow = true,
>           typename Allocator overflowAllocator = EASTLAllocator>
> class fixed_vector
>
> {
>    ...
> };
> [end quote]
>
> I have tried a similar approach using some sort of  
> fixed_buffer_with_overflow allocator, with no success. I'm not sure  
> SSO is even possible just using an allocator with the standard  
> containers, because I always end up with stateful allocators.
>
> So my question is if there is something similar already in boost.

A small vector with fixed capacity has been proposed a few years ago  
by Synge Todo. In discussions about initial interest it was said  
though that people would prefer a full-featured policy-based vector  
instead. Synge's code is thus not in Boost, but is available under the  
Boost license as part of the ALPS project at http://alps.comp-phys.org/

Matthias