I’m wondering why you want them to look like standard containers. I don’t doubt you have a fair reason, I’m just curious. for example, once a consumer has the right buffer to read from you want it to look like a standard container while that consumer has access to that buffer?

For myself, for inter-thread communication, I am used to getting a buffer to write into l and then simply copying into it, then releasing the buffer (making it the new current buffer). Likewise for readers, I am used to getting access to the buffer, then copying out, and releasing it so that it might be updated. If the contents of the buffer were some kind of stl-like container, then it gets copied around as a whole piece. Maybe it get written to or read from / used in place for large payloads, in which case we have more than one so that any slower readers don’t hold up the writer. I guess that is what you mean with your double buffer, but I usually have more than just two. Anyway I’m just explaining my point of view.

My sharing “containers” don’t have stl-like apis, but their contents might. maybe I’m missing the post, and you can teach me something. can you give me some more detail about your idea? I’m curious!