Utility functions for Erlang's gb_trees

The following functions are provided:

greatest_key_lt/2

Find the entry containing the greatest Key less than (lt) SearchKey in Tree.

-spec greatest_key_lt(SearchKey::term(), Tree::gb_tree()) ->
    'none' | {Key::term(), Value::term()}.

greatest_key_lte/2

Find the entry containing the greatest Key less than or equal (lte) to SearchKey in Tree.

-spec greatest_key_lte(SearchKey::term(), Tree::gb_tree()) ->
    'none' | {Key::term(), Value::term()}.

smallest_key_gt/2

Find the entry containing the smallest Key key greater than (gt) SearchKey in Tree.

-spec smallest_key_gt(SearchKey::term(), Tree::gb_tree()) ->
    'none' | {Key::term(), Value::term()}.

smallest_key_gte/2

Find the entry containing the smallest Key key greater than or equal (gte) to SearchKey in Tree.

-spec smallest_key_gte(SearchKey::term(), Tree::gb_tree()) ->
    'none' | {Key::term(), Value::term()}.