//@ run-pass #![feature(derive_smart_pointer, arbitrary_self_types)] use std::marker::SmartPointer; #[derive(SmartPointer)] #[repr(transparent)] struct MyPointer<'a, #[pointee] T: ?Sized> { ptr: &'a T, } impl Copy for MyPointer<'_, T> {} impl Clone for MyPointer<'_, T> { fn clone(&self) -> Self { Self { ptr: self.ptr } } } impl<'a, T: ?Sized> core::ops::Deref for MyPointer<'a, T> { type Target = T; fn deref(&self) -> &'a T { self.ptr } } struct MyValue(u32); impl MyValue { fn through_pointer(self: MyPointer<'_, Self>) -> u32 { self.ptr.0 } } trait MyTrait { fn through_trait(&self) -> u32; fn through_trait_and_pointer(self: MyPointer<'_, Self>) -> u32; } impl MyTrait for MyValue { fn through_trait(&self) -> u32 { self.0 } fn through_trait_and_pointer(self: MyPointer<'_, Self>) -> u32 { self.ptr.0 } } pub fn main() { let v = MyValue(10); let ptr = MyPointer { ptr: &v }; assert_eq!(v.0, ptr.through_pointer()); assert_eq!(v.0, ptr.through_pointer()); let dptr = ptr as MyPointer; assert_eq!(v.0, dptr.through_trait()); assert_eq!(v.0, dptr.through_trait_and_pointer()); }