src/test/ui/consts/const-eval/issue-50814-2.rs

// Copyright 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.

trait C {
    const BOO: usize;
}

trait Foo<T> {
    const BAR: usize;
}

struct A<T>(T);

impl<T: C> Foo<T> for A<T> {
    const BAR: usize = [5, 6, 7][T::BOO];
}

fn foo<T: C>() -> &'static usize {
    &<A<T> as Foo<T>>::BAR //~ ERROR erroneous constant used
//~| ERROR E0080
}

impl C for () {
    const BOO: usize = 42;
}

impl C for u32 {
    const BOO: usize = 1;
}

fn main() {
    println!("{:x}", foo::<()>() as *const usize as usize);
    println!("{:x}", foo::<u32>() as *const usize as usize);
    println!("{:x}", foo::<()>());
    println!("{:x}", foo::<u32>());
}