116 struct node {  struct
117     node* my_parent{};
120     node() = default;
121     node(node* parent, int ref_count) :  in node()  function
127 struct wait_node : node {
128     wait_node() : node{ nullptr, 1 } {}  in wait_node()
133 struct tree_node : public node {
137     tree_node(node* parent, int ref_count, small_object_allocator& alloc)  in tree_node()
138         : node{parent, ref_count}  in tree_node()
161 void fold_tree(node* n, const execution_data& ed) {  in fold_tree()
169         node* parent = n->my_parent;  in fold_tree()