| // 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. |
| |
| // Issue 27282: Example 2: This sidesteps the AST checks disallowing |
| // mutable borrows in match guards by hiding the mutable borrow in a |
| // guard behind a move (of the mutably borrowed match input) within a |
| // closure. |
| // |
| // This example is not rejected by AST borrowck (and then reliably |
| // reaches the panic code when executed, despite the compiler warning |
| // about that match arm being unreachable. |
| |
| #![feature(nll)] |
| |
| fn main() { |
| let b = &mut true; |
| match b { |
| &mut false => {}, |
| _ if { (|| { let bar = b; *bar = false; })(); |
| false } => { }, |
| &mut true => { println!("You might think we should get here"); }, |
| //~^ ERROR use of moved value: `b` [E0382] |
| _ => panic!("surely we could never get here, since rustc warns it is unreachable."), |
| } |
| } |
