// produce special borrowck message inside all kinds of loops struct FuncWrapper<'a, T : 'a> { func : fn(&'a mut T) -> () } impl<'a, T : 'a> FuncWrapper<'a, T> { fn in_loop(self, arg : &'a mut T) { loop { (self.func)(arg) //~ ERROR cannot borrow } } fn in_while(self, arg : &'a mut T) { while true { //~ WARN denote infinite loops with (self.func)(arg) //~ ERROR cannot borrow } } fn in_for(self, arg : &'a mut T) { let v : Vec<()> = vec![]; for _ in v.iter() { (self.func)(arg) //~ ERROR cannot borrow } } } fn main() { }