rust/src/test/run-pass/issue-27401-dropflag-reinit.rs
2016-10-18 23:23:40 +03:00

37 lines
1.1 KiB
Rust

// Copyright 2015 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.
// ignore-pretty issue #37201
// Check that when a `let`-binding occurs in a loop, its associated
// drop-flag is reinitialized (to indicate "needs-drop" at the end of
// the owning variable's scope).
struct A<'a>(&'a mut i32);
impl<'a> Drop for A<'a> {
fn drop(&mut self) {
*self.0 += 1;
}
}
fn main() {
let mut cnt = 0;
for i in 0..2 {
let a = A(&mut cnt);
if i == 1 { // Note that
break; // both this break
} // and also
drop(a); // this move of `a`
// are necessary to expose the bug
}
assert_eq!(cnt, 2);
}