//! What a system adds beyond winit. Each system has its own module with the same
//! functions and types, and the target picks the module, so the host calls one name and
//! carries no `cfg` of its own; a system winit alone covers gets the generic answers.
//!
//! The one type every module supplies is `Vsync`: the system's signal for each refresh of
//! a window's display, started with `Vsync::start` and paused with `set_paused`, or `None`
//! from a system that has none to give, which the host paces by a timer instead.
pub use *;
pub use *;