This PR adds #550's FlatContainer container, as well as a StreamCore::container<C>() method to use for hinting when containers are potentially ambiguous. Some amount of an experiment in ergonomics; the approach is #550 is still valid (specifying the container in the generics of the method), but this allows you to avoid that and only specify the container in a container::<HERE>() call.
This PR adds #550's
FlatContainercontainer, as well as aStreamCore::container<C>()method to use for hinting when containers are potentially ambiguous. Some amount of an experiment in ergonomics; the approach is #550 is still valid (specifying the container in the generics of the method), but this allows you to avoid that and only specify the container in acontainer::<HERE>()call.