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

   1 #![feature(allow_internal_unstable)]
   2 #![feature(const_add)]
   3 #![feature(const_trait_impl)]
   4 #![feature(staged_api)]
   5 #![stable(feature = "rust1", since = "1.0.0")]
   6
   7 #[stable(feature = "rust1", since = "1.0.0")]
   8 pub struct Int(i32);
   9
  10 #[stable(feature = "rust1", since = "1.0.0")]
  11 #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
  12 impl const std::ops::Sub for Int {
  13     type Output = Self;
  14
  15     fn sub(self, rhs: Self) -> Self {
  16         //~^ ERROR trait methods cannot be stable const fn
  17         Int(self.0 - rhs.0)
  18     }
  19 }
  20
  21 #[stable(feature = "rust1", since = "1.0.0")]
  22 #[rustc_const_unstable(feature = "const_add", issue = "none")]
  23 impl const std::ops::Add for Int {
  24     type Output = Self;
  25
  26     fn add(self, rhs: Self) -> Self {
  27         Int(self.0 + rhs.0)
  28     }
  29 }
  30
  31 #[stable(feature = "rust1", since = "1.0.0")]
  32 #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
  33 pub const fn foo() -> Int {
  34     Int(1i32) + Int(2i32)
  35     //~^ ERROR not yet stable as a const fn
  36 }
  37
  38 // ok
  39 #[stable(feature = "rust1", since = "1.0.0")]
  40 #[rustc_const_unstable(feature = "bar", issue = "none")]
  41 pub const fn bar() -> Int {
  42     Int(1i32) + Int(2i32)
  43 }
  44
  45 fn main() {}