//! Mirrors (`docs/design/bus.md`, "Mirrors"): data read every tick kept in
//! shared memory, written by its provider at the rate asked, read by
//! anyone in place — no call, no copy.
//!
//! * [`Store`] — the runtime's: key spaces, columns, mirrors, demand.
//! * [`view`] — what everyone else holds: columns and key spaces read (and
//! written, by a column's one writer) through their headers.
//! * [`Cell`] — what a row of a column is.
pub use ;
pub use KeySpace;
pub use ;
pub use ;
pub use ;