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// 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.
// This is testing an attempt to corrupt the discriminant of the match
// arm in a guard, followed by an attempt to continue matching on that
// corrupted discriminant in the remaining match arms.
//
// Basically this is testing that our new NLL feature of emitting a
// fake read on each match arm is catching cases like this.
//
// This case is interesting because it includes a guard that
// diverges, and therefore a single final fake-read at the very end
// after the final match arm would not suffice.
#![feature(nll)]
struct ForceFnOnce;
fn main() {
let mut x = &mut Some(&2);
let force_fn_once = ForceFnOnce;
match x {
&mut None => panic!("unreachable"),
&mut Some(&_) if {
// ForceFnOnce needed to exploit #27282
(|| { *x = None; drop(force_fn_once); })();
//~^ ERROR closure requires unique access to `x` but it is already borrowed [E0500]
false
} => {}
&mut Some(&a) if { // this binds to garbage if we've corrupted discriminant
println!("{}", a);
panic!()
} => {}
_ => panic!("unreachable"),
}
}
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