1 files changed, 18 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/optional/monad_plus.cpp b/src/boost/libs/hana/example/optional/monad_plus.cpp
new file mode 100644
index 000000000..d32681526
--- /dev/null
+++ b/src/boost/libs/hana/example/optional/monad_plus.cpp
@@ -0,0 +1,18 @@
+// 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/concat.hpp>
+#include <boost/hana/empty.hpp>
+#include <boost/hana/equal.hpp>
+#include <boost/hana/optional.hpp>
+namespace hana = boost::hana;
+
+
+static_assert(hana::concat(hana::nothing, hana::just('x')) == hana::just('x'), "");
+BOOST_HANA_CONSTANT_CHECK(hana::concat(hana::nothing, hana::nothing) == hana::nothing);
+static_assert(hana::concat(hana::just('x'), hana::just('y')) == hana::just('x'), "");
+BOOST_HANA_CONSTANT_CHECK(hana::empty<hana::optional_tag>() == hana::nothing);
+
+int main() { }