I am working on a circular queue library that contains a non-owning circular span, a fixed-sized circular array, and a dynamically resizable circular vector. Would you be interested in adding such a library to Boost? The design is inspired by Boost.CircularBuffer, std::span, and P0059R4 std::experimental::ring_span. The code can be found at: https://github.com/breese/trial.circular The documentation can be found at: https://github.com/breese/trial.circular/tree/develop/doc circular::span can be used to implement the P0059R4 ring_span, as shown in one of the example: https://github.com/breese/trial.circular/blob/develop/example/p0059/ring_spa... circular::span can also be used to implement most parts of boost::circular_buffer; all except insertions and erasure at arbitrary positions.