src/test/ui/type-alias-impl-trait/generic_duplicate_param_use.rs

   1 #![feature(type_alias_impl_trait)]
   2
   3 use std::fmt::Debug;
   4
   5 fn main() {}
   6
   7 // test that unused generic parameters are ok
   8 type TwoTys<T, U> = impl Debug;
   9
  10 type TwoLifetimes<'a, 'b> = impl Debug;
  11
  12 type TwoConsts<const X: usize, const Y: usize> = impl Debug;
  13
  14
  15 fn one_ty<T: Debug>(t: T) -> TwoTys<T, T> {
  16     t
  17     //~^ ERROR non-defining opaque type use in defining scope
  18 }
  19
  20 fn one_lifetime<'a>(t: &'a u32) -> TwoLifetimes<'a, 'a> {
  21     t
  22     //~^ ERROR non-defining opaque type use in defining scope
  23 }
  24
  25 fn one_const<const N: usize>(t: *mut [u8; N]) -> TwoConsts<N, N> {
  26     t
  27     //~^ ERROR non-defining opaque type use in defining scope
  28 }