rust/tests/ui/specialization/source-impl-requires-constr...

30 lines
808 B
Rust

//@ revisions: current next
//@ ignore-compare-mode-next-solver (explicit revisions)
//@[next] compile-flags: -Znext-solver
//@[next] check-pass
//@[current] known-bug: unknown
//@[current] failure-status: 101
//@[current] dont-check-compiler-stderr
// Tests that rebasing from the concrete impl to the default impl also processes the
// `[u32; 0]: IntoIterator<Item = ?U>` predicate to constrain the `?U` impl arg.
// This test also makes sure that we don't do anything weird when rebasing the args
// is ambiguous.
#![feature(specialization)]
//[next]~^ WARN the feature `specialization` is incomplete
trait Spec {
type Assoc;
}
default impl<T, U> Spec for T where T: IntoIterator<Item = U> {
type Assoc = U;
}
impl<T> Spec for [T; 0] {}
fn main() {
let x: <[_; 0] as Spec>::Assoc = 1;
}