/// Generates a sealed marker trait and one or more unit struct implementors.
///
/// Produces a `pub trait $trait: $sealed_trait {}` and, for each `$unit_type`,
/// a `#[derive(Debug, Clone, Copy)] pub struct $unit_type` with both the seal
/// and the marker trait implemented.
$+
};
}
/// Re-exports [`impl_sealed_marker_types!`] for use throughout the crate.
pub use impl_sealed_marker_types;