diff --git a/tests/ui/coroutine/copy-fast-path-query-cycle.rs b/tests/ui/coroutine/copy-fast-path-query-cycle.rs new file mode 100644 index 000000000000..644cba0d47af --- /dev/null +++ b/tests/ui/coroutine/copy-fast-path-query-cycle.rs @@ -0,0 +1,40 @@ +//@ edition: 2024 +//@ revisions: current next +//@[next] compile-flags: -Znext-solver +//@ check-pass + +// Regression test for #146813. We previously used a pseudo-canonical +// query during HIR typeck which caused a query cycle when looking at the +// witness of a coroutine. + +use std::future::Future; + +trait ConnectMiddleware {} + +trait ConnectHandler: Sized { + fn with(self, _: M) -> impl ConnectHandler + where + M: ConnectMiddleware, + { + LayeredConnectHandler + } +} + +struct LayeredConnectHandler; +impl ConnectHandler for LayeredConnectHandler {} +impl ConnectHandler for F where F: FnOnce() {} + +impl ConnectMiddleware for F +where + F: FnOnce() -> Fut, + Fut: Future + Send, +{ +} + +pub async fn fails() { + { || {} } + .with(async || ()) + .with(async || ()) + .with(async || ()); +} +fn main() {}