sourceturner
51 lines
1.4 KiB
Rust
51 lines
1.4 KiB
Rust
use core::cell::UnsafeCell;
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/// Wrapper over `UnsafeCell` that can directly be used in statics, where all modifications require
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/// unsafe.
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#[repr(transparent)]
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pub struct RawCell<T> {
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inner: UnsafeCell<T>,
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}
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impl<T> RawCell<T> {
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#[inline]
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pub const fn new(t: T) -> Self {
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Self {
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inner: UnsafeCell::new(t),
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}
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}
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#[inline]
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pub fn as_mut_ptr(&self) -> *mut T {
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self.inner.get()
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}
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#[inline]
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pub fn get_mut(&mut self) -> &mut T {
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self.inner.get_mut()
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}
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#[inline]
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pub fn into_inner(self) -> T {
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self.inner.into_inner()
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}
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#[inline]
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pub unsafe fn unsafe_ref(&self) -> &T {
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unsafe { &*self.inner.get() }
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}
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#[inline]
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pub unsafe fn unsafe_set(&self, t: T) {
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unsafe { *self.inner.get() = t };
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}
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#[inline]
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pub unsafe fn unsafe_mut(&self) -> &mut T {
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unsafe { &mut *self.inner.get() }
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}
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}
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// SAFETY: Sync requires that no safe interface be allowed to act on &self in a way that is
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// undefined behavior when accessed concurrently. The interface above only allows get, set, and
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// as_mut_ptr, where the former two that access memory are unsafe anyway.
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unsafe impl<T> Sync for RawCell<T> {}
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const _: () = {
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// Check that RawCell works for non-Sync types.
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static X: RawCell<*mut ()> = RawCell::new(core::ptr::null_mut());
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};
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