Struct tinyset::set64::Set64 [−][src]
pub struct Set64<T: Fits64>(_, _);
Expand description
A set type that can store any type that fits in a u64
. This set
type is very space-efficient in storing small or closely spaced
integers, while not being bad at storing large integers.
Major caveat The Set64
type defines iterators (drain()
and
iter()
) that iterate over T
rather than &T
. This is a break
with standard libray convention, and can be annoying if you are
translating code from HashSet
to Set64
. The motivation for
this is several-fold:
-
Set64
does not storeT
directly in its data structures (which would waste space), so there is no reference to the data to take. This does not make it impossible, but does mean we would have to fabricate aT
and return a reference to it, which is awkward and ugly. -
There is no inefficiency involved in returning
T
, since it is necessarily no larger than a pointer.
Examples
use tinyset::Set64;
let a: Set64<char> = "Hello world".chars().collect();
for x in "Hello world".chars() {
assert!(a.contains(&x));
}
for x in a {
assert!("Hello world".contains(x));
}
Storage details
Internally a Set64
is identical to a SetU64, so read there for
details. In short, small sets are the size of a pointer with no
heap storage. Densely packed sets are around a bit per member.
Intermediate sets have intermediate storage. The worst case
scenario is large integers widely spaced apart, in which case the
storage is similar to a std::collections::HashSet
.
Implementations
Creates an empty set with the specified capacity.
Adds a value to the set.
If the set did not have this value present, true
is returned.
If the set did have this value present, false
is returned.
Returns true if the set contains a value.
Removes an element, and returns true if that element was present.
Trait Implementations
Returns the union of self
and rhs
as a new Set64<T>
.
Examples
use tinyset::Set64;
let a: Set64<u32> = vec![1, 2, 3].into_iter().collect();
let b: Set64<u32> = vec![3, 4, 5].into_iter().collect();
let set = &a | &b;
let mut i = 0;
let expected = [1, 2, 3, 4, 5];
for x in set {
assert!(expected.contains(&x));
i += 1;
}
assert_eq!(i, expected.len());
Adds a bunch of elements to the set
Examples
use tinyset::Set64;
let mut a: Set64<u32> = vec![1, 2, 3].into_iter().collect();
a.extend(vec![3, 4, 5]);
let mut i = 0;
let expected = [1, 2, 3, 4, 5];
for x in a {
assert!(expected.contains(&x));
i += 1;
}
assert_eq!(i, expected.len());
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
Creates a value from an iterator. Read more
type Item = T
type Item = T
The type of the elements being iterated over.
Returns the difference of self
and rhs
as a new Set64<T>
.
Examples
use tinyset::Set64;
let a: Set64<u32> = vec![1, 2, 3].into_iter().collect();
let b: Set64<u32> = vec![3, 4, 5].into_iter().collect();
let set = &a - &b;
let mut i = 0;
let expected = [1, 2];
for x in set {
assert!(expected.contains(&x));
i += 1;
}
assert_eq!(i, expected.len());
Auto Trait Implementations
impl<T> RefUnwindSafe for Set64<T> where
T: RefUnwindSafe,
impl<T> UnwindSafe for Set64<T> where
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more