| // 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. |
| |
| #![feature(const_let)] |
| |
| fn main() { |
| // Tests the Collatz conjecture with an incorrect base case (0 instead of 1). |
| // The value of `n` will loop indefinitely (4 - 2 - 1 - 4). |
| let _ = [(); { |
| //~^ WARNING Constant evaluating a complex constant, this might take some time |
| //~| ERROR could not evaluate repeat length |
| let mut n = 113383; // #20 in https://oeis.org/A006884 |
| while n != 0 { //~ ERROR constant contains unimplemented expression type |
| n = if n % 2 == 0 { n/2 } else { 3*n + 1 }; |
| } |
| n |
| }]; |
| } |
