/// (ideally) or `PhantomData<*const T>` (if no lifetime applies), so
/// as not to indicate ownership.
///
+/// ## Layout
+///
+/// For all `T`, the following are guaranteed:
+/// * `size_of::<PhantomData<T>>() == 0`
+/// * `align_of::<PhantomData<T>>() == 1`
+///
/// [drop check]: ../../nomicon/dropck.html
#[lang = "phantom_data"]
#[stable(feature = "rust1", since = "1.0.0")]