diff options
Diffstat (limited to 'src/test/ui/auto-traits/typeck-auto-trait-no-supertraits.rs')
-rw-r--r-- | src/test/ui/auto-traits/typeck-auto-trait-no-supertraits.rs | 39 |
1 files changed, 0 insertions, 39 deletions
diff --git a/src/test/ui/auto-traits/typeck-auto-trait-no-supertraits.rs b/src/test/ui/auto-traits/typeck-auto-trait-no-supertraits.rs deleted file mode 100644 index 2a76893fe..000000000 --- a/src/test/ui/auto-traits/typeck-auto-trait-no-supertraits.rs +++ /dev/null @@ -1,39 +0,0 @@ -// This test is for #29859, we need to ensure auto traits, -// (also known previously as default traits), do not have -// supertraits. Since the compiler synthesizes these -// instances on demand, we are essentially enabling -// users to write axioms if we view trait selection, -// as a proof system. -// -// For example the below test allows us to add the rule: -// forall (T : Type), T : Copy -// -// Providing a copy instance for *any* type, which -// is most definitely unsound. Imagine copying a -// type that contains a mutable reference, enabling -// mutable aliasing. -// -// You can imagine an even more dangerous test, -// which currently compiles on nightly. -// -// fn main() { -// let mut i = 10; -// let (a, b) = copy(&mut i); -// println!("{:?} {:?}", a, b); -// } - -#![feature(auto_traits)] -#![feature(negative_impls)] - -auto trait Magic: Copy {} //~ ERROR E0568 -impl<T:Magic> Magic for T {} - -fn copy<T: Magic>(x: T) -> (T, T) { (x, x) } - -#[derive(Debug)] -struct NoClone; - -fn main() { - let (a, b) = copy(NoClone); - println!("{:?} {:?}", a, b); -} |