To GC or Not To GC in std.container.*

[Nordlöw]

What's the policy on using GC or not in std.container.* ?
- std.container.Array uses malloc for its allocation but
- RedBlackTree.allocate() returns a: new RBNode!Elem*

Is this because RBNode* should be reachable outside of 
RedBlackTree or is this a todo?