I\'m learning C++ and writing a binary search tree. The following is the code I wrote for my insert method.
BSTNode * BST::Insert(const std::string & v) {
Your compiler probably should have spotted this, but this line near the end of your helper:
if(n->right) Insert_Helper(v,n->right);
You probably should return whatever Insert_Helper returns:
Insert_Helper
if(n->right) return Insert_Helper(v,n->right);