from typing import Set
import csv


def get_all_ids(filename: str) -> Set:
    """Function that returns the set of all ids of all items saved in the file.

    Args:
        filename (str): File where items are saved.

    Returns:
        Set: Set of ids.
    """    
    
    ids = set()
    with open(filename, mode="r") as csvfile:
        reader = csv.DictReader(csvfile)
        for row in reader:
            ids.add(row['id'])
    return ids