// Copyright 2014 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 or the MIT license // , 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. #![feature(box_syntax)] fn a() { let mut x = 3; let c1 = |&mut:| x = 4; let c2 = |&mut:| x = 5; //~ ERROR cannot borrow `x` as mutable more than once } fn set(x: &mut isize) { *x = 4; } fn b() { let mut x = 3; let c1 = |&mut:| set(&mut x); let c2 = |&mut:| set(&mut x); //~ ERROR cannot borrow `x` as mutable more than once } fn c() { let mut x = 3; let c1 = |&mut:| x = 5; let c2 = |&mut:| set(&mut x); //~ ERROR cannot borrow `x` as mutable more than once } fn d() { let mut x = 3; let c1 = |&mut:| x = 5; let c2 = |&mut:| { let _y = |&mut:| set(&mut x); }; // (nested closure) //~^ ERROR cannot borrow `x` as mutable more than once } fn g() { struct Foo { f: Box } let mut x = box Foo { f: box 3 }; let c1 = |&mut:| set(&mut *x.f); let c2 = |&mut:| set(&mut *x.f); //~^ ERROR cannot borrow `x` as mutable more than once } fn main() { }