Crate enumset

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Expand description

A library for defining enums that can be used in compact bit sets. It supports arbitrarily large enums, and has very basic support for using them in constants.

The following feature flags may be used for this crate:

  • serde enables serialization support for EnumSet.
  • alloc enables functions that require allocation.

§Defining enums for use with EnumSet

Enums to be used with EnumSet should be defined using #[derive(EnumSetType)]:

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

For more information on more advanced use cases, see the documentation for #[derive(EnumSetType)].

§Working with EnumSets

EnumSets can be constructed via EnumSet::new() like a normal set. In addition, #[derive(EnumSetType)] creates operator overloads that allow you to create EnumSets 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 EnumSets and enums with #[derive(EnumSetType)]:

// Intersection of sets
assert_eq!((Enum::A | Enum::B) & Enum::C, EnumSet::empty());
assert_eq!((Enum::A | Enum::B) & Enum::A, Enum::A);
assert_eq!(Enum::A & Enum::B, EnumSet::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 enum_set! macro allows you to create EnumSets in constant contexts:

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

Mutable operations on the EnumSet otherwise similarly to Rust’s builtin sets:

let mut set = EnumSet::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§

  • enum_set
    Creates a EnumSet literal, which can be used in const contexts.

Structs§

Traits§

Derive Macros§