Add test case from #106. Refs #106.

Author: pdimov

test/Jamfile

@@ -250,6 +250,7 @@ run mp_similar.cpp ;
 run mp_map_find.cpp ;
 run mp_map_find_2.cpp ;
 run mp_map_find_3.cpp ;
+run mp_map_find_4.cpp ;
 run mp_map_contains.cpp ;
 run mp_map_insert.cpp ;
 run mp_map_replace.cpp ;

test/mp_map_find_4.cpp

@@ -0,0 +1,32 @@
+// Copyright 2016, 2020, 2024 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/mp11/map.hpp>
+#include <boost/mp11/list.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+template<class T> struct Wrap
+{
+    struct type {};
+};
+
+int main()
+{
+    using boost::mp11::mp_map_find;
+    using boost::mp11::mp_list;
+
+    using Int = Wrap<int>::type;
+    using Long = Wrap<long>::type;
+
+    using Map = mp_list<
+        mp_list<Int, void>,
+        mp_list<Long, void>
+    >;
+
+    BOOST_TEST_TRAIT_SAME( mp_map_find<Map, Int>, mp_list<Int, void> );
+    BOOST_TEST_TRAIT_SAME( mp_map_find<Map, Long>, mp_list<Long, void> );
+    BOOST_TEST_TRAIT_SAME( mp_map_find<Map, int>, void );
+
+    return boost::report_errors();
+}