change key types to any

tree.go

@@ -5,7 +5,7 @@ import (
 )
 
 // Node is a node on the binary search tree.
-type Node[K comparable, V any, C Sorter[K]] struct {
+type Node[K, V any, C Sorter[K]] struct {
 	lson, rson *Node[K, V, C]
 	parent     *Node[K, V, C]
 	bal        uint32 // for treap balancing
@@ -23,7 +23,7 @@ func (n *Node[K, V, C]) Key() K {
 // addresses and don't work with values.
 //
 // The zero value is a usable, empty tree.
-type Tree[K comparable, V any, C Sorter[K]] struct {
+type Tree[K, V any, C Sorter[K]] struct {
 	root *Node[K, V, C]
 }
 
@@ -58,6 +58,8 @@ func (t *Tree[K, V, C]) InsertNode(key K, value V) (node *Node[K, V, C], is_adde
 
 // realInsertNode recursivly searches and tries to insert the new node.
 // If the key is found, it's passed into *result.
+//
+// Returns the new node that should be placed in CUR's place (usually itself).
 func (t *Tree[K, V, C]) realInsertNode(cur, parent *Node[K, V, C], key K, value V, result **Node[K, V, C], is_added *bool) (node *Node[K, V, C]) {
 	var c C
 	if cur == nil {