templateKeylessMethods(Node, alias eb_first, alias eb_last)
Node*
first
()
out (node)
{
if (this.length)
{
assert (node, typeof(this).stringof ~ ".first: got a null node but the tree is not empty");
}
else
{
assert (!node, typeof(this).stringof ~ ".first: got a node but the tree is empty");
}
}