eyre/
ptr.rs

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1use std::{marker::PhantomData, ptr::NonNull};
2
3/// An owned pointer
4///
5/// **NOTE**: Does not deallocate when dropped
6pub(crate) struct OwnedPtr<T: ?Sized> {
7    ptr: NonNull<T>,
8}
9
10impl<T: ?Sized> Copy for OwnedPtr<T> {}
11
12impl<T: ?Sized> Clone for OwnedPtr<T> {
13    fn clone(&self) -> Self {
14        *self
15    }
16}
17
18unsafe impl<T> Send for OwnedPtr<T> where T: Send {}
19unsafe impl<T> Sync for OwnedPtr<T> where T: Send {}
20
21impl<T> OwnedPtr<T> {
22    pub(crate) fn new(value: T) -> Self {
23        Self::from_boxed(Box::new(value))
24    }
25
26    pub(crate) fn from_boxed(boxed: Box<T>) -> Self {
27        // Safety: `Box::into_raw` is guaranteed to be non-null
28        Self {
29            ptr: unsafe { NonNull::new_unchecked(Box::into_raw(boxed)) },
30        }
31    }
32
33    /// Convert the pointer to another type
34    pub(crate) fn cast<U>(self) -> OwnedPtr<U> {
35        OwnedPtr {
36            ptr: self.ptr.cast(),
37        }
38    }
39
40    /// Context the pointer into a Box
41    ///
42    /// # Safety
43    ///
44    /// Dropping the Box will deallocate a layout of `T` and run the destructor of `T`.
45    ///
46    /// A cast pointer must therefore be cast back to the original type before calling this method.
47    pub(crate) unsafe fn into_box(self) -> Box<T> {
48        unsafe { Box::from_raw(self.ptr.as_ptr()) }
49    }
50
51    pub(crate) const fn as_ref(&self) -> RefPtr<'_, T> {
52        RefPtr {
53            ptr: self.ptr,
54            _marker: PhantomData,
55        }
56    }
57
58    pub(crate) fn as_mut(&mut self) -> MutPtr<'_, T> {
59        MutPtr {
60            ptr: self.ptr,
61            _marker: PhantomData,
62        }
63    }
64}
65
66/// Convenience lifetime annotated mutable pointer which facilitates returning an inferred lifetime
67/// in a `fn` pointer.
68pub(crate) struct RefPtr<'a, T: ?Sized> {
69    pub(crate) ptr: NonNull<T>,
70    _marker: PhantomData<&'a T>,
71}
72
73/// Safety: RefPtr indicates a shared reference to a value and as such exhibits the same Send +
74/// Sync behavior of &'a T
75unsafe impl<'a, T: ?Sized> Send for RefPtr<'a, T> where &'a T: Send {}
76unsafe impl<'a, T: ?Sized> Sync for RefPtr<'a, T> where &'a T: Sync {}
77
78impl<'a, T: ?Sized> Copy for RefPtr<'a, T> {}
79impl<'a, T: ?Sized> Clone for RefPtr<'a, T> {
80    fn clone(&self) -> Self {
81        *self
82    }
83}
84
85impl<'a, T: ?Sized> RefPtr<'a, T> {
86    pub(crate) fn new(ptr: &'a T) -> Self {
87        Self {
88            ptr: NonNull::from(ptr),
89            _marker: PhantomData,
90        }
91    }
92
93    /// Convert the pointer to another type
94    pub(crate) fn cast<U>(self) -> RefPtr<'a, U> {
95        RefPtr {
96            ptr: self.ptr.cast(),
97            _marker: PhantomData,
98        }
99    }
100
101    /// Returns a shared reference to the owned value
102    ///
103    /// # Safety
104    ///
105    /// See: [`NonNull::as_ref`]
106    #[inline]
107    pub(crate) unsafe fn as_ref(&self) -> &'a T {
108        unsafe { self.ptr.as_ref() }
109    }
110}
111
112/// Convenience lifetime annotated mutable pointer which facilitates returning an inferred lifetime
113/// in a `fn` pointer.
114pub(crate) struct MutPtr<'a, T: ?Sized> {
115    pub(crate) ptr: NonNull<T>,
116    _marker: PhantomData<&'a mut T>,
117}
118
119/// Safety: RefPtr indicates an exclusive reference to a value and as such exhibits the same Send +
120/// Sync behavior of &'a mut T
121unsafe impl<'a, T: ?Sized> Send for MutPtr<'a, T> where &'a mut T: Send {}
122unsafe impl<'a, T: ?Sized> Sync for MutPtr<'a, T> where &'a mut T: Sync {}
123
124impl<'a, T: ?Sized> Copy for MutPtr<'a, T> {}
125impl<'a, T: ?Sized> Clone for MutPtr<'a, T> {
126    fn clone(&self) -> Self {
127        *self
128    }
129}
130
131impl<'a, T: ?Sized> MutPtr<'a, T> {
132    /// Convert the pointer to another type
133    pub(crate) fn cast<U>(self) -> MutPtr<'a, U> {
134        MutPtr {
135            ptr: self.ptr.cast(),
136            _marker: PhantomData,
137        }
138    }
139
140    /// Returns a mutable reference to the owned value with the lifetime decoupled from self
141    ///
142    /// # Safety
143    ///
144    /// See: [`NonNull::as_mut`]
145    #[inline]
146    pub(crate) unsafe fn into_mut(mut self) -> &'a mut T {
147        unsafe { self.ptr.as_mut() }
148    }
149}
eyre/ptr.rs

eyre/
ptr.rs
