const-exhaustive

Enumerate all values of a type at compile time.

Features

• All values of T: Exhaustive are stored in a GenericArray - allowing you to access all values at compile time, and in a const context.

• Composable with core types - supports [T; N], tuples up to arity 16, Option<T>, and other types in core.

• #[derive(Exhaustive)] - to implement it on your own types.

• #![no_std] and no alloc - you can use it anywhere.

Examples

use const_exhaustive::Exhaustive;

// there is 1 value of `()`
assert_eq!([()], <()>::ALL.as_slice());

// there are 2 values of `bool`
assert_eq!([false, true], bool::ALL.as_slice());

// works on types with generics
assert_eq!(
    [None, Some(false), Some(true)],
    Option::<bool>::ALL.as_slice()
);

// write your own exhaustive types
#[derive(Debug, Clone, Copy, PartialEq, Exhaustive)]
enum Direction {
    North,
    South,
    East,
    West,
}

assert_eq!(
    [
        Direction::North,
        Direction::South,
        Direction::East,
        Direction::West,
    ],
    Direction::ALL.as_slice()
);

// works on arbitrarily complex types
#[derive(Debug, Clone, Copy, PartialEq, Exhaustive)]
enum Complex {
    Direction(Direction),
    More {
        foo: Option<bool>,
        bar: (Result<Direction, [bool; 4]>),
    },
}

Testing

Run unit and doc tests:

cargo test

Run miri tests:

cargo +nightly miri test

Test generating docs:

RUSTDOCFLAGS="--cfg docsrs_dep" cargo +nightly doc --workspace --all-features