I tried giving this a run from CLion and it crashes if I search first, see

#include "trie.hpp" #include <iostream>

int main() { trie<char16_t> trie;

    // Greek
    std::cout << trie.search(u"υπολογιστής") << std::endl;
    std::cout << trie.search(u"υπολογιστης") << std::endl;

    // English
    std::cout << trie.search(u"computer") << std::endl;
    std::cout << trie.search(u"compute") << std::endl;


    // Greek
  trie.insert(u"υπολογιστής"); //crash


  // English
  trie.insert(u"computer");

  // Greek
  std::cout << trie.search(u"υπολογιστής") << std::endl;
  std::cout << trie.search(u"υπολογιστης") << std::endl;

  // English
  std::cout << trie.search(u"computer") << std::endl;
  std::cout << trie.search(u"compute") << std::endl;

  return 0;
}