[container] Proposal for ring queues

From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2020-05-21 22:17:50

Hi,

Some time ago I have proposed to include ring_queue and small_ring_queue 
containers to Boost.Container:

https://github.com/boostorg/container/pull/121

The ring queues work similarly to std::queue with the main difference 
being that they use a ring buffer internally to store elements. The 
small_ring_queue also allows to allocate a static storage for a fixed 
amount of elements. The benefit of this is that dynamic memory 
allocations can be practically avoided when the number of enqueued 
elements does not exceed some limit.

In his reply in that PR Ion was not very enthusiastic about including 
these containers into Boost.Container mostly because (a) there was 
presumably not much interest from users and (b) because the current 
implementation requires C++17 while Boost.Container supports C++03.

I would like to ask if there is interest in the community for these 
kinds of containers. I know I would find them useful, and at least one 
person commented in the PR to the same effect. However, I would still 
like to see if more people need this.

If there is interest, what would be the preferred course of action?

1. Should we work on inclusion into Boost.Container or maybe some other 
library? Candidates? Boost.CircularBuffer was mentioned in the PR, 
although I'm not sure it is suitable for these components. Creating a 
new submodule is also a possibility, although it seems like an overkill.

2. Somewhat related to p.1, what minimum C++ version is preferred. E.g. 
if we agree that Boost.Container is the right place for these 
components, I could work on lowering minimum C++ version, although C++03 
would complicate things considerably.

Thanks.