Function ele_index_to_child_indices 

pub fn ele_index_to_child_indices(
    elements: &[ElementDefinition],
    index: usize,
) -> Result<Vec<usize>, String>

Returns the indices of the direct child elements of the element at index.

Errors

Returns an error if:

• index is out of bounds.
• An element does not contain a path.
• The child matching regular expression cannot be compiled.