[eeps] EEP 46 updated

[Raimo Niskanen]

EEP 46: B-trees: balanced search trees of order n
has been updated by the author:

@@ -79,6 +79,16 @@ A general balanced tree iterator.
 
 ## EXPORTS ##
 
+### copy(Tree1, Tree2) -> Tree3 ###
+
+Types:
+
+    Tree1 = Tree2 = Tree3 = b_tree() | gb_trees:tree()
+
+Copies tree Tree1 to an empty tree Tree2. Both trees may be either 
+of type b-tree or binary tree (gb_trees). Returns the new tree 
+Tree3 of the same type as tree Tree2.
+
 ### delete(Key, B-Tree1) -> B-Tree2 ###
 
 Types:
@@ -550,6 +560,7 @@ The functional design of the module b\_trees is based
on the module gb\_trees:
      b_trees          | gb_trees
     ------------------|---------
      n/a              | balance/1
+     copy/2           | n/a
      delete/2         | delete/2
      delete_any/2     | delete_any/2
      empty/1          | empty/0

-- 

/ Raimo Niskanen, Erlang/OTP, Ericsson AB