1 files changed, 45 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/map/difference.cpp b/src/boost/libs/hana/example/map/difference.cpp
new file mode 100644
index 000000000..6b94b0a22
--- /dev/null
+++ b/src/boost/libs/hana/example/map/difference.cpp
@@ -0,0 +1,45 @@
+// Copyright Louis Dionne 2013-2017
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+
+#include <boost/hana/assert.hpp>
+#include <boost/hana/difference.hpp>
+#include <boost/hana/equal.hpp>
+#include <boost/hana/map.hpp>
+#include <boost/hana/string.hpp>
+
+#include <string>
+namespace hana = boost::hana;
+
+
+static auto m1 = hana::make_map(
+    hana::make_pair(BOOST_HANA_STRING("key1"), hana::type_c<std::string>),
+    hana::make_pair(BOOST_HANA_STRING("key2"), hana::type_c<std::string>)
+);
+
+static auto m2 = hana::make_map(
+    hana::make_pair(BOOST_HANA_STRING("key3"), hana::type_c<std::string>),
+    hana::make_pair(BOOST_HANA_STRING("key4"), hana::type_c<std::string>),
+    hana::make_pair(BOOST_HANA_STRING("key5"), hana::type_c<std::string>)
+);
+
+static auto m3 = hana::make_map(
+    hana::make_pair(BOOST_HANA_STRING("key1"), hana::type_c<std::string>),
+    hana::make_pair(BOOST_HANA_STRING("key4"), hana::type_c<int>),
+    hana::make_pair(BOOST_HANA_STRING("key2"), hana::type_c<long long>)
+);
+
+int main() {
+    BOOST_HANA_CONSTANT_CHECK(hana::difference(m1, m2) == m1);
+
+    BOOST_HANA_CONSTANT_CHECK(hana::difference(m1, m3) == hana::make_map());
+
+    BOOST_HANA_CONSTANT_CHECK(hana::difference(m3, m1) == hana::make_map(
+        hana::make_pair(BOOST_HANA_STRING("key4"), hana::type_c<int>)
+    ));
+
+    BOOST_HANA_CONSTANT_CHECK(hana::difference(m2, m3) == hana::make_map(
+        hana::make_pair(BOOST_HANA_STRING("key3"), hana::type_c<std::string>),
+        hana::make_pair(BOOST_HANA_STRING("key5"), hana::type_c<std::string>)
+    ));
+}