diff --git a/alib2std/src/extensions/container/set.hpp b/alib2std/src/extensions/container/set.hpp
index b94a10c7330ddf7feab44028d2de5c6bace0866a..469ead9170d1d6b64ee4129e68ad60f0de2739db 100644
--- a/alib2std/src/extensions/container/set.hpp
+++ b/alib2std/src/extensions/container/set.hpp
@@ -189,6 +189,54 @@ public:
 		return ext::iterator_range < decltype ( endIter ) > ( beginIter, endIter );
 	}
 
+	/**
+	 * \brief
+	 * Make range of elements with key equal to the @p key.
+	 *
+	 * \tparam K the key used in the query
+	 *
+	 * \param key the value used in the query
+	 *
+	 * \return selected range of elements
+	 */
+	template < class K >
+	auto equal_range ( K && key ) const & {
+		auto res = std::set < T, Cmp, Alloc >::equal_range ( std::forward < K > ( key ) );
+		return ext::iterator_range < decltype ( res.first ) > ( res.first, res.second );
+	}
+
+	/**
+	 * \brief
+	 * Make range of elements with key equal to the @p key.
+	 *
+	 * \tparam K the key used in the query
+	 *
+	 * \param key the value used in the query
+	 *
+	 * \return selected range of elements
+	 */
+	template < class K >
+	auto equal_range ( K && key ) & {
+		auto res = std::set < T, Cmp, Alloc >::equal_range ( std::forward < K > ( key ) );
+		return ext::iterator_range < decltype ( res.first ) > ( res.first, res.second );
+	}
+
+	/**
+	 * \brief
+	 * Make range of elements with key equal to the @p key.
+	 *
+	 * \tparam K the key used in the query
+	 *
+	 * \param key the value used in the query
+	 *
+	 * \return selected range of elements
+	 */
+	template < class K >
+	auto equal_range ( K && key ) && {
+		auto res = std::set < T, Cmp, Alloc >::equal_range ( std::forward < K > ( key ) );
+		return ext::make_iterator_range ( make_set_move_iterator < T > ( res.first ), make_set_move_iterator < T > ( res.second ) );
+	}
+
 	/**
 	 * \brief
 	 * Test whether the set contains a given key