src/tools/miri/tests/pass/arrays.rs

fn empty_array() -> [u16; 0] {
    []
}

fn mini_array() -> [u16; 1] {
    [42]
}

fn big_array() -> [u16; 5] {
    [5, 4, 3, 2, 1]
}

fn array_array() -> [[u8; 2]; 3] {
    [[5, 4], [3, 2], [1, 0]]
}

fn index_unsafe() -> i32 {
    let a = [0, 10, 20, 30];
    unsafe { *a.get_unchecked(2) }
}

fn index() -> i32 {
    let a = [0, 10, 20, 30];
    a[2]
}

fn array_repeat() -> [u8; 8] {
    [42; 8]
}

fn slice_index() -> u8 {
    let arr: &[_] = &[101, 102, 103, 104, 105, 106];
    arr[5]
}

fn from() {
    const N: usize = 16;
    type Array = [u8; N];
    let array: Array = [0; N];
    let slice: &[u8] = &array[..];

    let result = <&Array>::try_from(slice);
    assert_eq!(&array, result.unwrap());

    let vec = Vec::from(array);
    assert_eq!(vec.len(), N);
}

fn eq() {
    const N: usize = 16;
    type Array = [u8; N];
    let array1: Array = [0; N];
    let array2: Array = [0; N];
    let array3: Array = [1; N];
    assert_eq!(array1, array2);
    assert_ne!(array1, array3);
}

fn debug() {
    let array = [0u8, 42, 13, 71];
    println!("{:?}", array);
}

fn huge_zst() {
    fn id<T>(x: T) -> T {
        x
    }

    // A "huge" zero-sized array. Make sure we don't loop over it in any part of Miri.
    let val = [(); usize::MAX];
    id(val); // make a copy

    let val = [val; 2];
    id(val);

    // Also wrap it in a union (which, in particular, hits the logic for computing union padding).
    let _copy = std::mem::MaybeUninit::new(val);
}

fn main() {
    assert_eq!(empty_array(), []);
    assert_eq!(index_unsafe(), 20);
    assert_eq!(index(), 20);
    assert_eq!(slice_index(), 106);
    assert_eq!(big_array(), [5, 4, 3, 2, 1]);
    assert_eq!(array_array(), [[5, 4], [3, 2], [1, 0]]);
    assert_eq!(array_repeat(), [42; 8]);
    assert_eq!(mini_array(), [42]);
    from();
    eq();
    debug();
    huge_zst();
}