src/test/ui/consts/const-eval/dont_promote_unstable_const_fn.rs

   1 #![unstable(feature = "humans",
   2             reason = "who ever let humans program computers,
   3             we're apparently really bad at it",
   4             issue = "none")]
   5
   6 #![feature(staged_api)]
   7
   8 #[stable(feature = "rust1", since = "1.0.0")]
   9 #[rustc_const_unstable(feature="foo", issue = "none")]
  10 const fn foo() -> u32 { 42 }
  11
  12 fn meh() -> u32 { 42 }
  13
  14 const fn bar() -> u32 { foo() } //~ ERROR `foo` is not yet stable as a const fn
  15
  16 fn a() {
  17     let _: &'static u32 = &foo(); //~ ERROR temporary value dropped while borrowed
  18 }
  19
  20 fn main() {
  21     let _: &'static u32 = &meh(); //~ ERROR temporary value dropped while borrowed
  22     let x: &'static _ = &std::time::Duration::from_millis(42).subsec_millis();
  23     //~^ ERROR temporary value dropped while borrowed
  24 }