rust/src/test/ui/parser/trait-object-bad-parens.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

17 lines
575 B
Rust

#![feature(optin_builtin_traits)]
#![feature(negative_impls)]
#![allow(bare_trait_objects)]
auto trait Auto {}
fn main() {
let _: Box<((Auto)) + Auto>;
//~^ ERROR expected a path on the left-hand side of `+`, not `((Auto))`
let _: Box<(Auto + Auto) + Auto>;
//~^ ERROR expected a path on the left-hand side of `+`, not `(Auto + Auto)`
let _: Box<(Auto +) + Auto>;
//~^ ERROR expected a path on the left-hand side of `+`, not `(Auto)`
let _: Box<(dyn Auto) + Auto>;
//~^ ERROR expected a path on the left-hand side of `+`, not `(dyn Auto)`
}