Macro assertables::assert_set_subset_as_result

macro_rules! assert_set_subset_as_result {
    ($a:expr, $b:expr $(,)?) => { ... };
}

Assert a set is a subset of another.

• When true, return Result Ok(()).

• When true, return Result Err with a diagnostic message.

Examples

let a = [1, 2];
let b = [1, 2, 3];
let x = assert_set_subset_as_result!(&a, &b);
//-> Ok(())
let actual = x.unwrap();
let expect = ();
assert_eq!(actual, expect);

let a = [1, 2, 3];
let b = [1, 2];
let x = assert_set_subset_as_result!(&a, &b);
//-> Err(…)
let actual = x.unwrap_err();
let expect = concat!(
    "assertion failed: `assert_set_subset!(left, right)`\n",
    "  left: `{1, 2, 3}`,\n",
    " right: `{1, 2}`"
);
assert_eq!(actual, expect);

This implementation uses [BTreeSet] to count items and sort them.