rust/src/test/ui/error-codes/E0199.rs
Niko Matsakis fda3378e3f introduce negative_impls feature gate and document
They used to be covered by `optin_builtin_traits` but negative impls
are now applicable to all traits, not just auto traits.

This also adds docs in the unstable book for the current state of auto traits.
2020-03-26 06:52:55 -04:00

9 lines
160 B
Rust

#![feature(negative_impls)]
struct Foo;
trait Bar { }
unsafe impl Bar for Foo { } //~ ERROR implementing the trait `Bar` is not unsafe [E0199]
fn main() {
}