Add test/mp_from_sequence_3.cpp. Refs #103.

test/Jamfile

@@ -151,6 +151,7 @@ run mp_with_index.cpp ;
 run mp_with_index_cx.cpp ;
 run mp_from_sequence.cpp ;
 run mp_from_sequence_2.cpp ;
+run mp_from_sequence_3.cpp ;
 run mp_min_element.cpp ;
 run mp_min_element_2.cpp ;
 run mp_min_element_q.cpp ;

test/mp_from_sequence_3.cpp

@@ -0,0 +1,26 @@
+// Copyright 2017, 2025 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/mp11/algorithm.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+#include <type_traits>
+
+template<class T, T... I> struct S;
+
+enum class E { one, two, three };
+
+template<E e> using constant = std::integral_constant<E, e>;
+
+int main()
+{
+    using boost::mp11::mp_list;
+    using boost::mp11::mp_from_sequence;
+
+    BOOST_TEST_TRAIT_TRUE((std::is_same<mp_from_sequence<S<E>>, mp_list<>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<mp_from_sequence<S<E, E::one>>, mp_list<constant<E::one>>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<mp_from_sequence<S<E, E::one, E::three>>, mp_list<constant<E::one>, constant<E::three>>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<mp_from_sequence<S<E, E::one, E::two, E::three>>, mp_list<constant<E::one>, constant<E::two>, constant<E::three>>>));
+
+    return boost::report_errors();
+}