src/test/run-pass/traits/traits-repeated-supertrait.rs

   1 // run-pass
   2 // Test a case of a trait which extends the same supertrait twice, but
   3 // with difference type parameters. Test that we can invoke the
   4 // various methods in various ways successfully.
   5 // See also `compile-fail/trait-repeated-supertrait-ambig.rs`.
   6
   7
   8 trait CompareTo<T> {
   9     fn same_as(&self, t: T) -> bool;
  10 }
  11
  12 trait CompareToInts : CompareTo<i64> + CompareTo<u64> {
  13 }
  14
  15 impl CompareTo<i64> for i64 {
  16     fn same_as(&self, t: i64) -> bool { *self == t }
  17 }
  18
  19 impl CompareTo<u64> for i64 {
  20     fn same_as(&self, t: u64) -> bool { *self == (t as i64) }
  21 }
  22
  23 impl CompareToInts for i64 { }
  24
  25 fn with_obj(c: &dyn CompareToInts) -> bool {
  26     c.same_as(22_i64) && c.same_as(22_u64)
  27 }
  28
  29 fn with_trait<C:CompareToInts>(c: &C) -> bool {
  30     c.same_as(22_i64) && c.same_as(22_u64)
  31 }
  32
  33 fn with_ufcs1<C:CompareToInts>(c: &C) -> bool {
  34     CompareToInts::same_as(c, 22_i64) && CompareToInts::same_as(c, 22_u64)
  35 }
  36
  37 fn with_ufcs2<C:CompareToInts>(c: &C) -> bool {
  38     CompareTo::same_as(c, 22_i64) && CompareTo::same_as(c, 22_u64)
  39 }
  40
  41 fn main() {
  42     assert_eq!(22_i64.same_as(22_i64), true);
  43     assert_eq!(22_i64.same_as(22_u64), true);
  44     assert_eq!(with_trait(&22), true);
  45     assert_eq!(with_obj(&22), true);
  46     assert_eq!(with_ufcs1(&22), true);
  47     assert_eq!(with_ufcs2(&22), true);
  48 }