src/librustc_data_structures/ptr_key.rs

   1 use std::ops::Deref;
   2 use std::{hash, ptr};
   3
   4 /// A wrapper around reference that compares and hashes like a pointer.
   5 /// Can be used as a key in sets/maps indexed by pointers to avoid `unsafe`.
   6 #[derive(Debug)]
   7 pub struct PtrKey<'a, T>(pub &'a T);
   8
   9 impl<'a, T> Clone for PtrKey<'a, T> {
  10     fn clone(&self) -> Self {
  11         *self
  12     }
  13 }
  14
  15 impl<'a, T> Copy for PtrKey<'a, T> {}
  16
  17 impl<'a, T> PartialEq for PtrKey<'a, T> {
  18     fn eq(&self, rhs: &Self) -> bool {
  19         ptr::eq(self.0, rhs.0)
  20     }
  21 }
  22
  23 impl<'a, T> Eq for PtrKey<'a, T> {}
  24
  25 impl<'a, T> hash::Hash for PtrKey<'a, T> {
  26     fn hash<H: hash::Hasher>(&self, hasher: &mut H) {
  27         (self.0 as *const T).hash(hasher)
  28     }
  29 }
  30
  31 impl<'a, T> Deref for PtrKey<'a, T> {
  32     type Target = T;
  33
  34     fn deref(&self) -> &Self::Target {
  35         self.0
  36     }
  37 }