rust/src/test/ui/consts/const-eval/conditional_array_execution.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.

#![warn(const_err)]

const X: u32 = 5;
const Y: u32 = 6;
const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
//~^ WARN this constant cannot be used

fn main() {
    println!("{}", FOO);
    //~^ ERROR
    //~| ERROR
}