index_set/
bitset_mut.rs

1/// A trait for a mutate values in a bit set.
2pub trait BitSetMut<T> {
3    /// Clears the set
4    ///
5    /// # Example
6    ///
7    /// ```rust
8    /// use index_set::{BitSet, BitSetMut};
9    ///
10    /// let mut bitset: [u32; 4] = [0; 4];
11    /// bitset.insert(0);
12    /// assert!(!BitSet::is_empty(&bitset[..]));
13    ///
14    /// bitset.clear();
15    /// assert!(BitSet::is_empty(&bitset[..]));
16    /// ```
17    fn clear(&mut self);
18
19    /// Inserts the value into the set.
20    ///
21    /// Returns `true` if the value was already set.
22    /// Returns `None` if the set cannot hold the value.
23    ///
24    /// # Example
25    ///
26    /// ```rust
27    /// use index_set::{BitSet, BitSetMut};
28    ///
29    /// let mut bitset: [u32; 4] = [0; 4];
30    /// bitset.insert(0);
31    /// assert_eq!(bitset.has(0), true);
32    /// ```
33    fn insert(&mut self, _: T) -> Option<bool>;
34
35    /// Removes the value from the set
36    ///
37    /// Returns `Some(true)` if the value was already set.
38    /// Returns `None` if the set cannot hold the value.
39    ///
40    /// # Example
41    ///
42    /// ```rust
43    /// use index_set::{BitSet, BitSetMut};
44    ///
45    /// let mut bitset: [u32; 4] = [0; 4];
46    /// bitset.insert(42);
47    /// assert_eq!(bitset.has(42), true);
48    ///
49    /// bitset.remove(42);
50    /// assert_eq!(bitset.has(42), false);
51    /// ```
52    fn remove(&mut self, _: T) -> Option<bool>;
53}
54
55macro_rules! impl_deref_mut {
56    ($($target: ty),*) => {$(
57        impl<Set, T> BitSetMut<T> for $target
58        where
59            Set: BitSetMut<T> + ?Sized,
60        {
61            #[inline]
62            fn clear(&mut self) {
63                BitSetMut::clear(&mut **self)
64            }
65
66            #[inline]
67            fn insert(&mut self, index: T) -> Option<bool> {
68                BitSetMut::insert(&mut **self, index)
69            }
70
71            #[inline]
72            fn remove(&mut self, index: T) -> Option<bool> {
73                BitSetMut::remove(&mut **self, index)
74            }
75        }
76    )*}
77}
78
79impl_deref_mut! {
80    &mut Set, Box<Set>
81}
82
83macro_rules! impl_bit_set_mut {
84    [$($ty:tt),*] => {$(
85        impl BitSetMut<$ty> for [$ty] {
86            fn clear(&mut self) {
87                for slot in self {
88                    *slot = 0;
89                }
90            }
91
92            #[inline]
93            fn insert(&mut self, index: $ty) -> Option<bool> {
94                let slot_idx = usize::try_from(index / $ty::BITS as $ty).ok()?;
95                let mask = 1 << (index % $ty::BITS as $ty);
96                let slot = self.get_mut(slot_idx)?;
97
98                let old_value = *slot & mask != 0;
99                *slot |= mask;
100                Some(old_value)
101            }
102
103            #[inline]
104            fn remove(&mut self, index: $ty) -> Option<bool> {
105                let slot_idx = usize::try_from(index / $ty::BITS as $ty).ok()?;
106                let mask = 1 << (index % $ty::BITS as $ty);
107                let slot = self.get_mut(slot_idx)?;
108
109                let old_value = *slot & mask != 0;
110                *slot &= !mask;
111                Some(old_value)
112            }
113        }
114    )*};
115}
116
117impl_bit_set_mut! {
118    u32, u64, usize, u128
119}
index_set/bitset_mut.rs

index_set/
bitset_mut.rs
