| #![feature(unboxed_closures)] |
| |
| // Tests that we can't assign to or mutably borrow upvars from `Fn` |
| // closures (issue #17780) |
| |
| fn set(x: &mut usize) { *x = 5; } |
| |
| fn to_fn<A,F:Fn<A>>(f: F) -> F { f } |
| fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f } |
| |
| fn main() { |
| // By-ref captures |
| { |
| let mut x = 0; |
| let _f = to_fn(|| x = 42); //~ ERROR cannot assign |
| |
| let mut y = 0; |
| let _g = to_fn(|| set(&mut y)); //~ ERROR cannot borrow |
| |
| let mut z = 0; |
| let _h = to_fn_mut(|| { set(&mut z); to_fn(|| z = 42); }); //~ ERROR cannot assign |
| } |
| |
| // By-value captures |
| { |
| let mut x = 0; |
| let _f = to_fn(move || x = 42); //~ ERROR cannot assign |
| |
| let mut y = 0; |
| let _g = to_fn(move || set(&mut y)); //~ ERROR cannot borrow |
| |
| let mut z = 0; |
| let _h = to_fn_mut(move || { set(&mut z); to_fn(move || z = 42); }); //~ ERROR cannot assign |
| } |
| } |