value_ptr_example_tree.cpp

struct Tree {
  string const name;
  value_ptr<Tree> left;
  value_ptr<Tree> right;
  
  Tree(
    string const& name, 
    value_ptr<Tree> const& left = value_ptr<Tree>{}, 
    value_ptr<Tree> const& right = value_ptr<Tree>{})
    : name{name}
    , left{left}
    , right{right}
  {} 
};


int main() {
  Tree root = Tree{
    "root",
      Tree{"l0"}
      Tree{"r0"}
  };
  
  root.left = root; // Copy of root assigned to left
  root.right = root; // and we don't have cyclic references
}