rust/tests/ui/did_you_mean/recursion_limit.rs

// Test that the recursion limit can be changed and that the compiler
// suggests a fix. In this case, we have deeply nested types that will
// fail the `Send` check by overflow when the recursion limit is set
// very low.

#![allow(dead_code)]
#![recursion_limit="10"]

macro_rules! link {
    ($id:ident, $t:ty) => {
        enum $id { $id($t) }
    }
}

link! { A, B }
link! { B, C }
link! { C, D }
link! { D, E }
link! { E, F }
link! { F, G }
link! { G, H }
link! { H, I }
link! { I, J }
link! { J, K }
link! { K, L }
link! { L, M }
link! { M, N }

enum N { N(usize) }

fn is_send<T:Send>() { }

fn main() {
    is_send::<A>(); //~ ERROR overflow evaluating the requirement
}