1 files changed, 30 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/map/keys.cpp b/src/boost/libs/hana/example/map/keys.cpp
new file mode 100644
index 000000000..073d6dec6
--- /dev/null
+++ b/src/boost/libs/hana/example/map/keys.cpp
@@ -0,0 +1,30 @@
+// 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/contains.hpp>
+#include <boost/hana/integral_constant.hpp>
+#include <boost/hana/keys.hpp>
+#include <boost/hana/map.hpp>
+#include <boost/hana/pair.hpp>
+#include <boost/hana/permutations.hpp>
+#include <boost/hana/tuple.hpp>
+#include <boost/hana/type.hpp>
+
+#include <string>
+namespace hana = boost::hana;
+using namespace std::literals;
+
+
+int main() {
+    auto m = hana::make_map(
+        hana::make_pair(hana::int_c<1>, "foobar"s),
+        hana::make_pair(hana::type_c<void>, 1234)
+    );
+
+    // The order of the keys is unspecified.
+    BOOST_HANA_CONSTANT_CHECK(
+        hana::keys(m) ^hana::in^ hana::permutations(hana::make_tuple(hana::int_c<1>, hana::type_c<void>))
+    );
+}