rust/src/test/ui/async-await/issue-64130-3-other.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

27 lines
533 B
Rust

#![feature(optin_builtin_traits)]
#![feature(negative_impls)]
// edition:2018
// This tests the the unspecialized async-await-specific error when futures don't implement an
// auto trait (which is not Send or Sync) due to some type that was captured.
auto trait Qux { }
struct Foo;
impl !Qux for Foo {}
fn is_qux<T: Qux>(t: T) { }
async fn bar() {
let x = Foo;
baz().await;
}
async fn baz() { }
fn main() {
is_qux(bar());
//~^ ERROR the trait bound `Foo: Qux` is not satisfied in `impl std::future::Future`
}