tests/ui/transmute/ambiguity-in-closure-arg.rs

// Minimized test for <https://github.com/rust-lang/rust/issues/123461>.

struct Unconstrained<T>(T);

fn main() {
    unsafe { std::mem::transmute::<_, ()>(|o_b: Unconstrained<_>| {}) };
    //~^ ERROR type annotations needed
    // We unfortunately don't check `Wf(Unconstrained<_>)`, so we won't
    // hit an ambiguity error before checking the transmute. That means
    // we still may have inference variables in our transmute src.
}