src/test/ui/rfc-2632-const-trait-impl/stability.rs

   1 #![allow(incomplete_features)]
   2 #![feature(allow_internal_unstable)]
   3 #![feature(const_add)]
   4 #![feature(const_trait_impl)]
   5 #![feature(staged_api)]
   6
   7 pub struct Int(i32);
   8
   9 #[stable(feature = "rust1", since = "1.0.0")]
  10 #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
  11 impl const std::ops::Sub for Int {
  12     type Output = Self;
  13
  14     fn sub(self, rhs: Self) -> Self {
  15         //~^ ERROR trait methods cannot be stable const fn
  16         Int(self.0 - rhs.0)
  17     }
  18 }
  19
  20 #[rustc_const_unstable(feature = "const_add", issue = "none")]
  21 impl const std::ops::Add for Int {
  22     type Output = Self;
  23
  24     fn add(self, rhs: Self) -> Self {
  25         Int(self.0 + rhs.0)
  26     }
  27 }
  28
  29 #[stable(feature = "rust1", since = "1.0.0")]
  30 #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
  31 pub const fn foo() -> Int {
  32     Int(1i32) + Int(2i32)
  33     //~^ ERROR not yet stable as a const fn
  34 }
  35
  36 // ok
  37 #[stable(feature = "rust1", since = "1.0.0")]
  38 #[rustc_const_unstable(feature = "bar", issue = "none")]
  39 pub const fn bar() -> Int {
  40     Int(1i32) + Int(2i32)
  41 }
  42
  43 fn main() {}