input: Write a function to search for a user-input string in a given list of strings using regular expressions. If a match is found, return "String matches", else return "String doesn't match". If the list is empty, return "No strings to match".
  import re 
  
  # Example assert test cases
  assert search_string_matches(["First", "Second", "Third"], "Second") == "String matches"
  assert search_string_matches(["First", "Second", "Third"], "Fourth") == "String doesn't match"
  assert search_string_matches([], "Any") == "No strings to match"
  assert search_string_matches(["First", "Second", "Third"], "find") == "String doesn't match"
  assert search_string_matches(["First", "Second", "Third"], "First Second") == "String matches"
output: def search_string_matches(string_list, user_input):
      if not string_list:
          return "No strings to match"
      for s in string_list:
          if re.search(user_input, s):
              return "String matches"
      return "String doesn't match"