//! A synchronous time source for [blocking retry](super).
use ;
/// A synchronous time source: read "now", and block for a duration.
///
/// Injected so tests can supply a mock that advances a *virtual* clock and returns from
/// `sleep` instantly. Open on purpose: implement it for a mock or a simulation runtime.
///
/// This is the blocking counterpart of mettle's async `Clock` trait; the two are separate
/// because the async one's `sleep` returns a `Future` and this one just blocks.
/// A [`Clock`] backed by [`std::thread::sleep`] and [`std::time::Instant`].
;