| use std::cell::RefCell; |
| |
| fn main() { |
| let mut y = 1; |
| let c = RefCell::new(vec![]); |
| c.push(Box::new(|| y = 0)); |
| c.push(Box::new(|| y = 0)); |
| //~^ ERROR cannot borrow `y` as mutable more than once at a time |
| } |
| |
| fn ufcs() { |
| let mut y = 1; |
| let c = RefCell::new(vec![]); |
| |
| Push::push(&c, Box::new(|| y = 0)); |
| Push::push(&c, Box::new(|| y = 0)); |
| //~^ ERROR cannot borrow `y` as mutable more than once at a time |
| } |
| |
| trait Push<'c> { |
| fn push<'f: 'c>(&self, push: Box<dyn FnMut() + 'f>); |
| } |
| |
| impl<'c> Push<'c> for RefCell<Vec<Box<dyn FnMut() + 'c>>> { |
| fn push<'f: 'c>(&self, fun: Box<dyn FnMut() + 'f>) { |
| self.borrow_mut().push(fun) |
| } |
| } |
