src/test/run-pass/issue-37655.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Regression test for #37655. The problem was a false edge created by
  12 // coercion that wound up requiring that `'a` (in `split()`) outlive
  13 // `'b`, which shouldn't be necessary.
  14
  15 #![allow(warnings)]
  16
  17 trait SliceExt<T> {
  18     type Item;
  19
  20     fn get_me<I>(&self, index: I) -> &I::Output
  21         where I: SliceIndex<Self::Item>;
  22 }
  23
  24 impl<T> SliceExt<T> for [T] {
  25     type Item = T;
  26
  27     fn get_me<I>(&self, index: I) -> &I::Output
  28         where I: SliceIndex<T>
  29     {
  30         panic!()
  31     }
  32 }
  33
  34 pub trait SliceIndex<T> {
  35     type Output: ?Sized;
  36 }
  37
  38 impl<T> SliceIndex<T> for usize {
  39     type Output = T;
  40 }
  41
  42 fn foo<'a, 'b>(split: &'b [&'a [u8]]) -> &'a [u8] {
  43     split.get_me(0)
  44 }
  45
  46 fn main() { }