src/test/compile-fail/issue-40288-2.rs

   1 // Copyright 2017 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 fn prove_static<T: 'static + ?Sized>(_: &'static T) {}
  12
  13 fn lifetime_transmute_slice<'a, T: ?Sized>(x: &'a T, y: &T) -> &'a T {
  14     let mut out = [x];
  15     {
  16         let slice: &mut [_] = &mut out;
  17         slice[0] = y;
  18     }
  19     out[0]
  20     //~^ ERROR 19:5: 19:11: explicit lifetime required in the type of `y` [E0621]
  21 }
  22
  23 struct Struct<T, U: ?Sized> {
  24     head: T,
  25     _tail: U
  26 }
  27
  28 fn lifetime_transmute_struct<'a, T: ?Sized>(x: &'a T, y: &T) -> &'a T {
  29     let mut out = Struct { head: x, _tail: [()] };
  30     {
  31         let dst: &mut Struct<_, [()]> = &mut out;
  32         dst.head = y;
  33     }
  34     out.head
  35     //~^ ERROR 34:5: 34:13: explicit lifetime required in the type of `y` [E0621]
  36 }
  37
  38 fn main() {
  39     prove_static(lifetime_transmute_slice("", &String::from("foo")));
  40     prove_static(lifetime_transmute_struct("", &String::from("bar")));
  41 }