Struct PhantomContravariantLifetime
pub struct PhantomContravariantLifetime<'a>(/* private fields */);🔬This is a nightly-only experimental API. (phantom_variance_markers #135806)
Expand description
Zero-sized type used to mark a lifetime as contravariant.
Contravariant lifetimes must live at most as long as declared. See the reference for more information.
Note: If 'a is otherwise covariant or invariant, the resulting type is invariant.
§Layout
For all 'a, the following are guaranteed:
size_of::<PhantomContravariantLifetime<'a>>() == 0align_of::<PhantomContravariantLifetime<'a>>() == 1