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// This is a regression test for issues that came up during review of the (closed)
// PR #132289; this single-crate test case is
// the first example from @steffahn during review.
// https://github.com/rust-lang/rust/pull/132289#issuecomment-2564492153
//@ check-pass
type A = &'static [usize; 1];
type B = &'static [usize; 100];
type DynSomething = dyn Something<Assoc = A>;
trait Super {
type Assoc;
}
impl Super for Foo {
type Assoc = A;
}
trait IsDynSomething {}
impl IsDynSomething for DynSomething {}
impl<T: ?Sized> Super for T
where
T: IsDynSomething,
{
type Assoc = B;
}
trait Something: Super {
fn method(&self) -> Self::Assoc;
}
struct Foo;
impl Something for Foo {
fn method(&self) -> Self::Assoc {
&[1337]
}
}
fn main() {
let x = &Foo;
let y: &DynSomething = x;
// no surprises here
let _arr1: A = x.method();
// this (`_arr2`) can't ever become B either, soundly
let _arr2: A = y.method();
// there aren't any other arrays being defined anywhere in this
// test case, besides the length-1 one containing [1337]
}
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