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-rw-r--r--lib/stdlib/src/ordsets.erl11
1 files changed, 9 insertions, 2 deletions
diff --git a/lib/stdlib/src/ordsets.erl b/lib/stdlib/src/ordsets.erl
index 569407f5ef..176047079b 100644
--- a/lib/stdlib/src/ordsets.erl
+++ b/lib/stdlib/src/ordsets.erl
@@ -1,7 +1,7 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2018. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
@@ -19,7 +19,7 @@
-module(ordsets).
--export([new/0,is_set/1,size/1,to_list/1,from_list/1]).
+-export([new/0,is_set/1,size/1,is_empty/1,to_list/1,from_list/1]).
-export([is_element/2,add_element/2,del_element/2]).
-export([union/2,union/1,intersection/2,intersection/1]).
-export([is_disjoint/2]).
@@ -60,6 +60,13 @@ is_set([], _) -> true.
size(S) -> length(S).
+%% is_empty(OrdSet) -> boolean().
+%% Return 'true' if OrdSet is an empty set, otherwise 'false'.
+-spec is_empty(Ordset) -> boolean() when
+ Ordset :: ordset(_).
+
+is_empty(S) -> S=:=[].
+
%% to_list(OrdSet) -> [Elem].
%% Return the elements in OrdSet as a list.