src/test/ui/traits/alias/bounds.rs

   1 // run-pass
   2
   3 #![feature(trait_alias)]
   4
   5 use std::marker::PhantomData;
   6
   7 trait Empty {}
   8 trait EmptyAlias = Empty;
   9 trait CloneDefault = Clone + Default;
  10 trait SendSyncAlias = Send + Sync;
  11 trait WhereSendAlias = where Self: Send;
  12 trait SendEqAlias<T> = Send where T: PartialEq<Self>;
  13 trait I32Iterator = Iterator<Item = i32>;
  14
  15 #[allow(dead_code)]
  16 struct Foo<T: SendSyncAlias>(PhantomData<T>);
  17 #[allow(dead_code)]
  18 struct Bar<T>(PhantomData<T>) where T: SendSyncAlias;
  19
  20 impl dyn EmptyAlias {}
  21
  22 impl<T: SendSyncAlias> Empty for T {}
  23
  24 fn a<T: CloneDefault>() -> (T, T) {
  25     let one = T::default();
  26     let two = one.clone();
  27     (one, two)
  28 }
  29
  30 fn b(x: &impl SendEqAlias<i32>) -> bool {
  31     22_i32 == *x
  32 }
  33
  34 fn c<T: I32Iterator>(x: &mut T) -> Option<i32> {
  35     x.next()
  36 }
  37
  38 fn d<T: SendSyncAlias>() {
  39     is_send_and_sync::<T>();
  40 }
  41
  42 fn is_send_and_sync<T: Send + Sync>() {}
  43
  44 fn main() {
  45     let both = a::<i32>();
  46     assert_eq!(both.0, 0);
  47     assert_eq!(both.1, 0);
  48     let both: (i32, i32) = a();
  49     assert_eq!(both.0, 0);
  50     assert_eq!(both.1, 0);
  51
  52     assert!(b(&22));
  53
  54     assert_eq!(c(&mut vec![22].into_iter()), Some(22));
  55
  56     d::<i32>();
  57 }