C++ dictionary trie implementation -

i getting segfault in insert function on line:

current->isword = true; 

everything compiles fine no warnings or errors (g++ -wall -wextra). main function calls insert function once , won't work. here code; hybrid between .h , .cpp file:

const int alphabetsize = 26;  struct node {     bool isword;     node* child[alphabetsize]; };  dictionary::dictionary() {     initnode(head); //node* head; defined in .h file under private: }  bool dictionary::isprefix(string s) {     node* current = endofstring(s, false);     if (current == null)     {         return false;     }     else     {         return true;     } }  bool dictionary::isword(string s) {     node* current = endofstring(s, false);     if (current == null)     {         return false;     }     else     {         return current->isword;     } }  void dictionary::insert(string s) {     node* current = endofstring(s, true);     current->isword = true; //segfault here }  //initializes new node void dictionary::initnode(node* current) {     current = new node;     current->isword = false;     (int = 0; < alphabetsize; i++)     {        current->child[i] = null;     } }  //returns pointer node of last character in string //isinsert tells whether needs initialize new nodes node* dictionary::endofstring(string s, bool isinsert) {     node* current = head;     node* next = head;     (unsigned int = 0; < s.length(); i++)     {         if (isalpha(s[i]) == true)         {             int letter = (tolower(s[i]) - 'a');             next = current->child[letter];             if (next == null)             {                 if (isinsert == false)                 {                     return null;                 }                  initnode(next);                 current->child[letter] = next;             }             current = current->child[letter];         }     }      return current; } 

initnode creates new node , initializes it, discarded. because current passed value, when modified inside of function, changes not propagate outside of initnode. straightforward fix make pass reference:

void dictionary::initnode(node*& current)