src/test/ui/dynamically-sized-types/dst-index.rs

   1 // run-pass
   2 #![allow(unused_variables)]
   3 // Test that overloaded index expressions with DST result types
   4 // work and don't ICE.
   5
   6 use std::ops::Index;
   7 use std::fmt::Debug;
   8
   9 struct S;
  10
  11 impl Index<usize> for S {
  12     type Output = str;
  13
  14     fn index<'a>(&'a self, _: usize) -> &'a str {
  15         "hello"
  16     }
  17 }
  18
  19 struct T;
  20
  21 impl Index<usize> for T {
  22     type Output = dyn Debug + 'static;
  23
  24     fn index<'a>(&'a self, idx: usize) -> &'a (dyn Debug + 'static) {
  25         static X: usize = 42;
  26         &X as &(dyn Debug + 'static)
  27     }
  28 }
  29
  30 fn main() {
  31     assert_eq!(&S[0], "hello");
  32     let _ = &T[0];
  33     // let x = &x as &Debug;
  34 }