#![feature(unsize, dispatch_from_dyn)] use std::{ ops::DispatchFromDyn, marker::{Unsize, PhantomData}, }; struct WrapperWithExtraField(T, i32); impl DispatchFromDyn> for WrapperWithExtraField where T: DispatchFromDyn, {} //~^^^ ERROR [E0378] struct MultiplePointers{ ptr1: *const T, ptr2: *const T, } impl DispatchFromDyn> for MultiplePointers where T: Unsize, {} //~^^^ ERROR [E0378] struct NothingToCoerce { data: PhantomData, } impl DispatchFromDyn> for NothingToCoerce {} //~^ ERROR [E0378] #[repr(C)] struct HasReprC(Box); impl DispatchFromDyn> for HasReprC where T: Unsize, {} //~^^^ ERROR [E0378] #[repr(align(64))] struct OverAlignedZst; struct OverAligned(Box, OverAlignedZst); impl DispatchFromDyn> for OverAligned where T: Unsize, {} //~^^^ ERROR [E0378] fn main() {}