| // Copyright 2017 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. |
| |
| // Tests that two closures cannot simultaneously have mutable |
| // access to the variable, whether that mutable access be used |
| // for direct assignment or for taking mutable ref. Issue #6801. |
| |
| // compile-flags: -Z borrowck=compare |
| |
| #![feature(box_syntax)] |
| |
| fn to_fn_mut<F: FnMut()>(f: F) -> F { f } |
| |
| fn a() { |
| let mut x = 3; |
| let c1 = to_fn_mut(|| x = 4); |
| let c2 = to_fn_mut(|| x = 5); //~ ERROR cannot borrow `x` as mutable more than once |
| //~| ERROR cannot borrow `x` as mutable more than once |
| drop((c1, c2)); |
| } |
| |
| fn set(x: &mut isize) { |
| *x = 4; |
| } |
| |
| fn b() { |
| let mut x = 3; |
| let c1 = to_fn_mut(|| set(&mut x)); |
| let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as mutable more than once |
| //~| ERROR cannot borrow `x` as mutable more than once |
| drop((c1, c2)); |
| } |
| |
| fn c() { |
| let mut x = 3; |
| let c1 = to_fn_mut(|| x = 5); |
| let c2 = to_fn_mut(|| set(&mut x)); //~ ERROR cannot borrow `x` as mutable more than once |
| //~| ERROR cannot borrow `x` as mutable more than once |
| drop((c1, c2)); |
| } |
| |
| fn d() { |
| let mut x = 3; |
| let c1 = to_fn_mut(|| x = 5); |
| let c2 = to_fn_mut(|| { let _y = to_fn_mut(|| set(&mut x)); }); // (nested closure) |
| //~^ ERROR cannot borrow `x` as mutable more than once |
| //~| ERROR cannot borrow `x` as mutable more than once |
| drop((c1, c2)); |
| } |
| |
| fn g() { |
| struct Foo { |
| f: Box<isize> |
| } |
| |
| let mut x: Box<_> = box Foo { f: box 3 }; |
| let c1 = to_fn_mut(|| set(&mut *x.f)); |
| let c2 = to_fn_mut(|| set(&mut *x.f)); |
| //~^ ERROR cannot borrow `x` as mutable more than once |
| //~| ERROR cannot borrow `x` as mutable more than once |
| drop((c1, c2)); |
| } |
| |
| fn main() { |
| } |