Function union_inds 

pub fn union_inds<I: IndexLike>(indices_a: &[I], indices_b: &[I]) -> Vec<I>

Find the union of two index collections.

Returns all unique indices from both collections (matched by ID). This corresponds to ITensors.jl’s unioninds function.

Time complexity: O(n + m) where n = len(indices_a), m = len(indices_b).

Arguments

• indices_a - First collection of indices
• indices_b - Second collection of indices

Returns

A vector containing all unique indices from both collections.

Example

use tensor4all_core::index::{DefaultIndex as Index, DynId};
use tensor4all_core::index_ops::union_inds;

let i = Index::new_dyn(2);
let j = Index::new_dyn(3);
let k = Index::new_dyn(4);

let indices_a = vec![i.clone(), j.clone()];
let indices_b = vec![j.clone(), k.clone()];

let union = union_inds(&indices_a, &indices_b);
assert_eq!(union.len(), 3);  // i, j, k