zr/
opaque.rs

1// Copyright 2026 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use core::cell::UnsafeCell;
6use core::mem::MaybeUninit;
7
8/// A wrapper for types that are opaque to Rust.
9///
10/// This is used to wrap C++ objects that Rust should not access directly.
11/// It provides a raw pointer to the inner data for use in FFI.
12#[repr(transparent)]
13pub struct Opaque<T>(MaybeUninit<UnsafeCell<T>>);
14
15impl<T> Opaque<T> {
16    /// Creates a new `Opaque` value.
17    pub const fn new(value: T) -> Self {
18        Self(MaybeUninit::new(UnsafeCell::new(value)))
19    }
20
21    /// Creates an uninitialized `Opaque` value.
22    pub const fn uninit() -> Self {
23        Self(MaybeUninit::uninit())
24    }
25
26    /// Returns a raw pointer to the opaque data.
27    pub fn get(&self) -> *mut T {
28        let ptr = self.0.as_ptr();
29        UnsafeCell::raw_get(ptr)
30    }
31}
zr/opaque.rs

zr/
opaque.rs
