tests/ui/lifetimes/lifetime-bound-will-change-warning.rs

   1 // aux-build:lifetime_bound_will_change_warning_lib.rs
   2
   3 // Test that various corner cases cause an error. These are tests
   4 // that used to pass before we tweaked object defaults.
   5
   6 #![allow(dead_code)]
   7 #![allow(unused_variables)]
   8
   9
  10 extern crate lifetime_bound_will_change_warning_lib as lib;
  11
  12 fn just_ref(x: &dyn Fn()) {
  13 }
  14
  15 fn ref_obj(x: &Box<dyn Fn()>) {
  16     // this will change to &Box<Fn()+'static>...
  17
  18     // Note: no warning is issued here, because the type of `x` will change to 'static
  19     if false { ref_obj(x); }
  20 }
  21
  22 fn test1<'a>(x: &'a Box<dyn Fn() + 'a>) {
  23     // just_ref will stay the same.
  24     just_ref(&**x)
  25 }
  26
  27 fn test1cc<'a>(x: &'a Box<dyn Fn() + 'a>) {
  28     // same as test1, but cross-crate
  29     lib::just_ref(&**x)
  30 }
  31
  32 fn test2<'a>(x: &'a Box<dyn Fn() + 'a>) {
  33     // but ref_obj will not, so warn.
  34     ref_obj(x)
  35     //~^ ERROR borrowed data escapes
  36 }
  37
  38 fn test2cc<'a>(x: &'a Box<dyn Fn() + 'a>) {
  39     // same as test2, but cross crate
  40     lib::ref_obj(x)
  41     //~^ ERROR borrowed data escapes
  42 }
  43
  44 fn test3<'a>(x: &'a Box<dyn Fn() + 'static>) {
  45     // here, we have a 'static bound, so even when ref_obj changes, no error results
  46     ref_obj(x)
  47 }
  48
  49 fn test3cc<'a>(x: &'a Box<dyn Fn() + 'static>) {
  50     // same as test3, but cross crate
  51     lib::ref_obj(x)
  52 }
  53
  54
  55 fn main() {
  56 }