// Original code (./not_unpin.rs): // // ```rust // #![allow(dead_code)] // // use pin_project::pin_project; // // #[pin_project(!Unpin)] // pub struct Struct { // #[pin] // pinned: T, // unpinned: U, // } // // fn main() { // fn _is_unpin() {} // // _is_unpin::>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned // } // ``` #![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)] #![allow(clippy::needless_lifetimes)] use pin_project::pin_project; // #[pin_project(!Unpin)] pub struct Struct { // #[pin] pinned: T, unpinned: U, } const _: () = { pub(crate) struct __StructProjection<'pin, T, U> where Struct: 'pin, { pinned: ::pin_project::__private::Pin<&'pin mut (T)>, unpinned: &'pin mut (U), } pub(crate) struct __StructProjectionRef<'pin, T, U> where Struct: 'pin, { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U), } impl Struct { pub(crate) fn project<'pin>( self: ::pin_project::__private::Pin<&'pin mut Self>, ) -> __StructProjection<'pin, T, U> { unsafe { let Self { pinned, unpinned } = self.get_unchecked_mut(); __StructProjection { pinned: ::pin_project::__private::Pin::new_unchecked(pinned), unpinned, } } } pub(crate) fn project_ref<'pin>( self: ::pin_project::__private::Pin<&'pin Self>, ) -> __StructProjectionRef<'pin, T, U> { unsafe { let Self { pinned, unpinned } = self.get_ref(); __StructProjectionRef { pinned: ::pin_project::__private::Pin::new_unchecked(pinned), unpinned, } } } } // Ensure that it's impossible to use pin projections on a #[repr(packed)] // struct. // // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34 // for details. #[forbid(unaligned_references, safe_packed_borrows)] fn __assert_not_repr_packed(this: &Struct) { let _ = &this.pinned; let _ = &this.unpinned; } // Create `Unpin` impl that has trivial `Unpin` bounds. // // See https://github.com/taiki-e/pin-project/issues/102#issuecomment-540472282 // for details. impl<'pin, T, U> ::pin_project::__private::Unpin for Struct where ::pin_project::__private::Wrapper<'pin, ::pin_project::__private::PhantomPinned>: ::pin_project::__private::Unpin { } // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it. // // To ensure that users don't accidentally write a non-functional `UnsafeUnpin` // impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin` // impl, they'll get a "conflicting implementations of trait" error when // coherence checks are run. #[doc(hidden)] unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Struct where ::pin_project::__private::Wrapper<'pin, ::pin_project::__private::PhantomPinned>: ::pin_project::__private::Unpin { } // Ensure that struct does not implement `Drop`. // // See ./struct-default-expanded.rs for details. trait StructMustNotImplDrop {} #[allow(clippy::drop_bounds, drop_bounds)] impl StructMustNotImplDrop for T {} impl StructMustNotImplDrop for Struct {} // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally // write a non-functional `PinnedDrop` impls. #[doc(hidden)] impl ::pin_project::__private::PinnedDrop for Struct { unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {} } }; fn main() { fn _is_unpin() {} // _is_unpin::>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned }