rust/tests/ui/closures/deduce-signature/supertrait-signature-inference-issue-23012.rs
lcnr 03878c682a hir typeck: look into nested goals
uses a `ProofTreeVisitor` to look into nested
goals when looking at the pending obligations
during hir typeck. Used by closure signature
inference, coercion, and for async functions.
2024-04-25 19:44:00 +00:00

33 lines
791 B
Rust

//@ revisions: current next
//@ ignore-compare-mode-next-solver (explicit revisions)
//@[next] compile-flags: -Znext-solver
//@ check-pass
// Checks that we can infer a closure signature even if the `FnOnce` bound is
// a supertrait of the obligations we have currently registered for the Ty var.
pub trait Receive<T, E>: FnOnce(Result<T, E>) {
fn receive(self, res: Result<T, E>);
}
impl<T, E, F: FnOnce(Result<T, E>)> Receive<T, E> for F {
fn receive(self, res: Result<T, E>) {
self(res)
}
}
pub trait Async<T, E> {
fn receive<F: Receive<T, E>>(self, f: F);
}
impl<T, E> Async<T, E> for Result<T, E> {
fn receive<F: Receive<T, E>>(self, f: F) {
f(self)
}
}
pub fn main() {
Ok::<u32, ()>(123).receive(|res| {
res.unwrap();
});
}