impl<T: ?Sized> cmp::Eq for $t<T> {}
如果代码没有实现,你为什么要写它?这种情况在许多地方都会发生,特别是与Eq有关的情况。
#[unstable(feature = "structural_match", issue = "31434")]
impl<T: ?Sized> StructuralPartialEq for $t<T> {}
#[unstable(feature = "structural_match", issue = "31434")]
impl<T: ?Sized> StructuralEq for $t<T> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized> Copy for $t<T> {}
impl<T: ?Sized> !Freeze for UnsafeCell<T> {}
unsafe impl<T: ?Sized> Freeze for PhantomData<T> {}
unsafe impl<T: ?Sized> Freeze for *const T {}
unsafe impl<T: ?Sized> Freeze for *mut T {}
unsafe impl<T: ?Sized> Freeze for &T {}
unsafe impl<T: ?Sized> Freeze for &mut T {}
Ord
的例子吗?我不明白如果不实现fn cmp(&self, other: &Self) -> Ordering;
它是如何实现的。 - John Kugelman