C++17 Tree Traversal with Fold Expressions

Question

I'm looking at the same tree traversal example as THIS POST. My VS is not supporting C++17 to see Fold Expresion inner workings. I guess this line:

Node* node = traverse(root, left, right);

would only traverse the binary tree from the root to the first leaf node and return? Or is it a complete preorder traversal?
How to implement Pre- Post- and Inorder traversals using Fold Expressions?