src/test/ui/feature-gate-underscore_const_names.rs

// Copyright 2012-2018 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(const_let)]

trait Trt {}
struct Str {}

impl Trt for Str {}

const _ : () = {
    use std::marker::PhantomData;
    struct ImplementsTrait<T: Trt>(PhantomData<T>);
    let _ = ImplementsTrait::<Str>(PhantomData);
    ()
};

fn main() {}