Crate big_enum_set

A library for defining enums that can be used in compact bit sets. The code is based on the enum_set crate, except that the backing store used is an array of usize. This enables use with enums with large number of variants. The API is very similar to that of enumset.

For serde support, enable the serde feature.

Defining enums for use with BigEnumSet

Enums to be used with BigEnumSet should be defined using #[derive(BigEnumSetType)]:

#[derive(BigEnumSetType, Debug)]
pub enum Enum {
   A, B, C, D, E, F, G,
}

Working with BigEnumSets

BigEnumSets can be constructed via BigEnumSet::new() like a normal set. In addition, #[derive(BigEnumSetType)] creates operator overloads that allow you to create BigEnumSets like so:

let new_set = Enum::A | Enum::C | Enum::G;
assert_eq!(new_set.len(), 3);

All bitwise operations you would expect to work on bitsets also work on both BigEnumSets and enums with #[derive(BigEnumSetType)]:

// Intersection of sets
assert_eq!((Enum::A | Enum::B) & Enum::C, BigEnumSet::empty());
assert_eq!((Enum::A | Enum::B) & Enum::A, Enum::A);
assert_eq!(Enum::A & Enum::B, BigEnumSet::empty());

// Symmetric difference of sets
assert_eq!((Enum::A | Enum::B) ^ (Enum::B | Enum::C), Enum::A | Enum::C);
assert_eq!(Enum::A ^ Enum::C, Enum::A | Enum::C);

// Difference of sets
assert_eq!((Enum::A | Enum::B | Enum::C) - Enum::B, Enum::A | Enum::C);

// Complement of sets
assert_eq!(!(Enum::E | Enum::G), Enum::A | Enum::B | Enum::C | Enum::D | Enum::F);

The big_enum_set! macro allows you to create BigEnumSets in constant contexts:

const CONST_SET: BigEnumSet<Enum> = big_enum_set!(Enum::A | Enum::B);
assert_eq!(CONST_SET, Enum::A | Enum::B);

Mutable operations on the BigEnumSet otherwise work basically as expected:

let mut set = BigEnumSet::new();
set.insert(Enum::A);
set.insert_all(Enum::E | Enum::G);
assert!(set.contains(Enum::A));
assert!(!set.contains(Enum::B));
assert_eq!(set, Enum::A | Enum::E | Enum::G);

Macros

big_enum_set

Creates a BigEnumSet literal, which can be used in const contexts.

Structs

BigEnumSet	An efficient set type for enums.
EnumSetIter	The iterator used by BigEnumSet.

Traits

BigEnumSetType

The trait used to define enum types that may be used with BigEnumSet.

Derive Macros

BigEnumSetType