rust/tests/ui/traits/next-solver/dont-remap-tait-substs.rs

20 lines
463 B
Rust

//@ compile-flags: -Znext-solver
//@ check-pass
// Makes sure we don't prepopulate the MIR typeck of `define`
// with `Foo<T, U> = T`, but instead, `Foo<B, A> = B`, so that
// the param-env predicates actually apply.
#![feature(type_alias_impl_trait)]
type Foo<T: Send, U> = impl NeedsSend<T>;
trait NeedsSend<T> {}
impl<T: Send> NeedsSend<T> for T {}
fn define<A, B: Send>(a: A, b: B, _: Foo<B, A>) {
let y: Option<Foo<B, A>> = Some(b);
}
fn main() {}