3 use std::cell::RefCell;
8 struct S<'a, T:FnMut() + 'static + ?Sized>(&'a mut T);
9 impl<'a, T:?Sized + FnMut() + 'static> DerefMut for S<'a, T> {
10 fn deref_mut(&mut self) -> &mut Self::Target { &mut self.0 }
12 impl<'a, T:?Sized + FnMut() + 'static> Deref for S<'a, T> {
13 type Target = dyn FnMut() + 'a;
14 fn deref(&self) -> &Self::Target { &self.0 }
19 get_icon: Mutex<Box<dyn FnMut() -> u32>>,
23 fn get_icon(&self) -> impl '_ + std::ops::DerefMut<Target=Box<dyn FnMut() -> u32>> {
24 self.get_icon.lock().unwrap()
28 let mut get_icon = self.get_icon();
29 let _rgba_icon = (*get_icon)();
37 type Target = dyn FnMut() + 'static;
38 fn deref(&self) -> &Self::Target {
43 impl DerefMut for Foo {
44 fn deref_mut(&mut self) -> &mut Self::Target {
52 let mut s = S(&mut f);
55 //Diggsey/Mark-Simulacrum example
56 let a: Rc<RefCell<dyn FnMut()>> = Rc::new(RefCell::new(||{}));