From 614dec90a7b1abe17d39d613bbaca4a6198aa240 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Mon, 7 Jan 2019 22:45:51 +0200
Subject: [PATCH] Add test/mp_set_intersection_sf.cpp

---
 include/boost/mp11/set.hpp      |  2 +-
 test/Jamfile                    |  1 +
 test/mp_set_intersection_sf.cpp | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 test/mp_set_intersection_sf.cpp

diff --git a/include/boost/mp11/set.hpp b/include/boost/mp11/set.hpp
index 45ba982..d8d17b5 100644
--- a/include/boost/mp11/set.hpp
+++ b/include/boost/mp11/set.hpp
@@ -144,7 +144,7 @@ template<class... S> struct in_all_sets
     template<class T> using fn = mp_all< mp_set_contains<S, T>... >;
 };
 
-template<class L, class... S> using mp_set_intersection_ = mp_copy_if_q<L, detail::in_all_sets<S...>>;
+template<class L, class... S> using mp_set_intersection_ = mp_if< mp_all<mp_is_list<L>, mp_is_list<S>...>, mp_copy_if_q<L, detail::in_all_sets<S...>> >;
 
 template<class... S> struct mp_set_intersection_impl
 {
diff --git a/test/Jamfile b/test/Jamfile
index 16509e6..b2460ba 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -138,6 +138,7 @@ run mp_set_union_sf.cpp ;
 run mp_set_difference.cpp ;
 run mp_set_difference_sf.cpp ;
 run mp_set_intersection.cpp ;
+run mp_set_intersection_sf.cpp ;
 
 # function
 run mp_all.cpp ;
diff --git a/test/mp_set_intersection_sf.cpp b/test/mp_set_intersection_sf.cpp
new file mode 100644
index 0000000..21af2ef
--- /dev/null
+++ b/test/mp_set_intersection_sf.cpp
@@ -0,0 +1,32 @@
+
+// Copyright 2019 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+
+#include <boost/mp11/set.hpp>
+#include <boost/mp11/utility.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+int main()
+{
+    using boost::mp11::mp_set_intersection;
+    using boost::mp11::mp_valid;
+    using boost::mp11::mp_list;
+
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, void, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, void, void, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, void, void, void, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, void, void, void, void, void>));
+
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, mp_list<>, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, mp_list<>, mp_list<>, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, mp_list<>, mp_list<>, mp_list<>, void>));
+    BOOST_TEST_TRAIT_FALSE((mp_valid<mp_set_intersection, mp_list<>, mp_list<>, mp_list<>, mp_list<>, void>));
+
+    return boost::report_errors();
+}