1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2024 Google LLC. All rights reserved. 3 // 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file or at 6 // https://developers.google.com/open-source/licenses/bsd 7 8 // Macro to create structs that will act as opaque pointees. These structs are 9 // never intended to be dereferenced in Rust. 10 // This is a workaround until stabilization of [`extern type`]. 11 // TODO: convert to extern type once stabilized. 12 // [`extern type`]: https://github.com/rust-lang/rust/issues/43467 13 macro_rules! opaque_pointee { 14 ($name: ident) => { 15 #[repr(C)] 16 pub struct $name { 17 _data: [u8; 0], 18 _marker: core::marker::PhantomData<(*mut u8, core::marker::PhantomPinned)>, 19 } 20 }; 21 } 22 23 pub(crate) use opaque_pointee; 24