rust/src/test/ui/issues/issue-40510-4.rs

// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![feature(rustc_attrs)]
#![allow(unused)]

fn f() {
    let x: Vec<()> = Vec::new();

    || {
        || {
            x.len()
        }
    };
}

#[rustc_error]
fn main() {} //~ ERROR compilation successful