devela/data/uid/pin/
mod.rs

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1// devela::data::uid::pin
2//
3//!
4//
5
6#[cfg(feature = "alloc")]
7mod r#box;
8#[cfg(feature = "alloc")]
9pub use r#box::IdPinBox;
10
11use crate::{addr_of, Pin};
12
13/// A unique identifier based on a pinned stack-allocated reference.
14///
15/// `IdPin` generates a unique ID by pinning a value on the stack,
16/// ensuring that the ID is based on the stack memory address
17/// for the lifetime of the reference.
18///
19/// It doesn't implement `Clone` or `Default`.
20///
21#[cfg_attr(feature = "alloc", doc = "See also [`IdPinBox`].")]
22///
23/// # Example
24/// ```
25/// # use devela::IdPin;
26/// let mut data1: u8 = 0;
27/// let id1 = IdPin::new(&mut data1);
28/// ```
29///
30#[doc = crate::doc_!(vendor: "object-id")]
31pub struct IdPin<'a> {
32    inner: Pin<&'a mut u8>,
33}
34
35impl<'a> IdPin<'a> {
36    /// Creates a new `IdPin` with a unique stack memory address.
37    ///
38    /// Expects a mutable reference to a `u8` `data` that will be pinned.
39    pub fn new(data: &'a mut u8) -> Self {
40        let inner = Pin::new(data);
41        Self { inner }
42    }
43
44    /// Returns the unique ID as a `usize`, derived from the stack memory address.
45    pub fn as_usize(&self) -> usize {
46        addr_of!(*self.inner) as usize
47    }
48}
49
50mod impl_traits {
51    use crate::{impl_trait, IdPin, Ordering, Ptr};
52
53    impl_trait![fmt::Debug for IdPin<'a> |self, f| write!(f, "{}", self.as_usize())];
54
55    impl_trait![Hash for IdPin<'a> |self, s| self.as_usize().hash(s)];
56
57    impl PartialEq for IdPin<'_> {
58        fn eq(&self, other: &Self) -> bool {
59            Ptr::eq(&*self.inner, &*other.inner)
60        }
61    }
62    impl Eq for IdPin<'_> {}
63
64    impl PartialOrd for IdPin<'_> {
65        fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
66            Some(self.as_usize().cmp(&other.as_usize()))
67        }
68    }
69    impl Ord for IdPin<'_> {
70        fn cmp(&self, other: &Self) -> Ordering {
71            self.as_usize().cmp(&other.as_usize())
72        }
73    }
74}
devela/data/uid/pin/mod.rs

devela/data/uid/pin/
mod.rs
