Enum Flags
enumflags
defines a BitFlags<T>
type for representing a set of named boolean values
efficiently, where T
is an enum with explicitly defined values. Semantically similar to a
HashSet<EnumWithoutAssociatedData>
, but much more efficient.
Example
extern crate enumflags2;
#[macro_use]
extern crate enumflags2_derive;
use enumflags2::BitFlags;
#[derive(EnumFlags, Copy, Clone, Debug, PartialEq)]
#[repr(u8)]
enum Test {
A = 0b0001,
B = 0b0010,
C = 0b0100,
D = 0b1000,
}
fn main() {
let a_b = Test::A | Test::B; // BitFlags<Test>
let a_c = Test::A | Test::C;
let b_c_d = Test::C | Test::B | Test::D;
// BitFlags<Test>(0b11, [A, B])
println!("{:?}", a_b);
// BitFlags<Test>(0b1, [A])
println!("{:?}", a_b & a_c);
// Iterate over the flags like a normal set!
assert_eq!(a_b.iter().collect::<Vec<_>>(), &[Test::A, Test::B]);
assert!(a_b.contains(Test::A));
assert!(b_c_d.contains(Test::B | Test::C));
assert!(!(b_c_d.contains(a_b)));
assert!(a_b.intersects(a_c));
assert!(!(a_b.intersects(Test::C | Test::D)));
}