Boost logo

Boost :

Subject: Re: [boost] Stack-based vector container
From: Michael Caisse (boost_at_[hidden])
Date: 2010-12-28 18:17:37

On 12/28/2010 03:03 PM, Gregory Crosswhite wrote:
> Hey everyone,
> In the course of my work as a computational scientist I have written a
> container that emulates std::vector, but which is backed by an array
> whose size is fixed at compile time. Concretely, the class looks
> something like the following:
> template<typename T,unsigned int buffer_size> class static_vector {
> ...
> protected:
> T data[buffer_size];
> T* end_ptr;
> size_t current_size;
> }
> where in the [...] there are methods that emulate (at this time,
> partially) the interface of std::vector, save that the size of the
> static_vector is not allowed to grow beyond the buffer_size.
> The advantage of using a static_vector over vector is performance. In
> my code I have performed benchmarks that show up to a 30% performance
> boost of static_vector over vector; the benefit occurs most stongly
> when working with lots of arrays of small objects, so that the use of
> dynamic memory rather than stack memory appears to add significant
> overhead to the computation. (Note that I when running these
> benchmarks I would use std::vector::reserve() to pre-allocate the
> array so that std::vector would not perform multiple allocations as
> the container grew, so that should not have been a source of overhead.)
> It seems to me that it would be useful to have this functionality
> generally available as a library, and in particular it might be a good
> fit for the boost family of libraries. Is there any interest out
> there for having such a library in boost? If so, I would be happy to
> do the work of taking what I have and fleshing it out so that it can
> function as a drop-in replacement for vector, which means modeling the
> Random Access Container and Back Insertion Sequence concepts as well
> as adding capacity() and reserve(size_t) (no-op) methods.
> Thoughts?

How is this different than boost::array?

Michael Caisse
Object Modeling Designs

Boost list run by bdawes at, gregod at, cpdaniel at, john at