| // Tests that a closure which requires mutable access to the referent |
| // of an `&mut` requires a "unique" borrow -- that is, the variable to |
| // be borrowed (here, `x`) will not be borrowed *mutably*, but |
| // may be *immutable*, but we cannot allow |
| // multiple borrows. |
| |
| |
| |
| fn get(x: &isize) -> isize { |
| *x |
| } |
| |
| fn set(x: &mut isize) -> isize { |
| *x |
| } |
| |
| fn a(x: &mut isize) { |
| let c1 = || get(x); |
| let c2 = || get(x); |
| c1(); |
| c2(); |
| } |
| |
| fn b(x: &mut isize) { |
| let c1 = || get(x); |
| let c2 = || set(x); //~ ERROR closure requires unique access to `x` |
| c1; |
| } |
| |
| fn c(x: &mut isize) { |
| let c1 = || get(x); |
| let c2 = || { get(x); set(x); }; //~ ERROR closure requires unique access to `x` |
| c1; |
| } |
| |
| fn d(x: &mut isize) { |
| let c1 = || set(x); |
| let c2 = || set(x); //~ ERROR two closures require unique access to `x` at the same time |
| c1; |
| } |
| |
| fn e(x: &'static mut isize) { |
| let c1 = |y: &'static mut isize| x = y; |
| //~^ ERROR cannot assign to `x`, as it is not declared as mutable |
| c1; |
| } |
| |
| fn f(x: &'static mut isize) { |
| let c1 = || x = panic!(); // OK assignment is unreachable. |
| c1; |
| } |
| |
| fn main() { |
| } |