ayy lmao

template<class ItemType>
bool BinarySearchTree<ItemType>::contains(const ItemType& item) const {

  //inner function to find recursively thru tree, captures itself to recur.
  std::function<bool(BinaryNode<ItemType> *, const ItemType &)> finder =
    [&finder](BinaryNode<ItemType> * node, const ItemType & arg){
    //case 1: item is found
    if(node->getItem() == arg){
      return true;
    } else {

      //decide where to go next
      BinaryNode<ItemType>* direction = (arg < this->getItem()) ?
      //ternary for less than checks path AND sets direction
      [&direction, node, arg](){ if(node->getLeftChildPtr() != nullptr) direction = node->getLeftChildPtr();  }() :
      //ternary for greater than checks path AND sets direction
      [&direction, node, arg](){ if(node->getRightChildPtr() != nullptr) direction = node->getRightChildPtr();  }();


      //since we were carefull we can check direction once and recurr
      if(direction != nullptr){
        finder(direction);
      } else {
        return false;
      }
    }
  };

  return finder(this->rootPtr, item);
}