diff options
Diffstat (limited to 'library/alloc/src/collections/btree/testing/ord_chaos.rs')
-rw-r--r-- | library/alloc/src/collections/btree/testing/ord_chaos.rs | 81 |
1 files changed, 0 insertions, 81 deletions
diff --git a/library/alloc/src/collections/btree/testing/ord_chaos.rs b/library/alloc/src/collections/btree/testing/ord_chaos.rs deleted file mode 100644 index 96ce7c157..000000000 --- a/library/alloc/src/collections/btree/testing/ord_chaos.rs +++ /dev/null @@ -1,81 +0,0 @@ -use std::cell::Cell; -use std::cmp::Ordering::{self, *}; -use std::ptr; - -// Minimal type with an `Ord` implementation violating transitivity. -#[derive(Debug)] -pub enum Cyclic3 { - A, - B, - C, -} -use Cyclic3::*; - -impl PartialOrd for Cyclic3 { - fn partial_cmp(&self, other: &Self) -> Option<Ordering> { - Some(self.cmp(other)) - } -} - -impl Ord for Cyclic3 { - fn cmp(&self, other: &Self) -> Ordering { - match (self, other) { - (A, A) | (B, B) | (C, C) => Equal, - (A, B) | (B, C) | (C, A) => Less, - (A, C) | (B, A) | (C, B) => Greater, - } - } -} - -impl PartialEq for Cyclic3 { - fn eq(&self, other: &Self) -> bool { - self.cmp(&other) == Equal - } -} - -impl Eq for Cyclic3 {} - -// Controls the ordering of values wrapped by `Governed`. -#[derive(Debug)] -pub struct Governor { - flipped: Cell<bool>, -} - -impl Governor { - pub fn new() -> Self { - Governor { flipped: Cell::new(false) } - } - - pub fn flip(&self) { - self.flipped.set(!self.flipped.get()); - } -} - -// Type with an `Ord` implementation that forms a total order at any moment -// (assuming that `T` respects total order), but can suddenly be made to invert -// that total order. -#[derive(Debug)] -pub struct Governed<'a, T>(pub T, pub &'a Governor); - -impl<T: Ord> PartialOrd for Governed<'_, T> { - fn partial_cmp(&self, other: &Self) -> Option<Ordering> { - Some(self.cmp(other)) - } -} - -impl<T: Ord> Ord for Governed<'_, T> { - fn cmp(&self, other: &Self) -> Ordering { - assert!(ptr::eq(self.1, other.1)); - let ord = self.0.cmp(&other.0); - if self.1.flipped.get() { ord.reverse() } else { ord } - } -} - -impl<T: PartialEq> PartialEq for Governed<'_, T> { - fn eq(&self, other: &Self) -> bool { - assert!(ptr::eq(self.1, other.1)); - self.0.eq(&other.0) - } -} - -impl<T: Eq> Eq for Governed<'_, T> {} |