I'm trying to put all words in a trie in a string, a word is detonated by the eow field being true for a certain character in the trie data structure, hence a trie can could have letters than lead up to no word, for ex "abc" is in the trie but "c"'s eow field is false so "abc" is not a word

Here is my Data structure

struct Trie {

  bool eow; //when a Trie field isWord = true, hence there is a word
  char letter;
  Trie *letters[27];

}; 

and here is my attemped print-all function, basically trying to return all words in one string seperated by spaces for words

string printAll( string word, Trie& data)
{
  if (data.eow == 1)
    return word + " ";
  for (int i = 0; i < 26; i++) {
    if (data.letters[i] != NULL)
     printAll( word + data.letters[i]->letter, *(data.letters[i]));
 }
  return "";
}

Its not outputting what i want, any suggestions?