1 files changed, 27 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/sequence/foldable.cpp b/src/boost/libs/hana/example/sequence/foldable.cpp
new file mode 100644
index 000000000..cdef35f17
--- /dev/null
+++ b/src/boost/libs/hana/example/sequence/foldable.cpp
@@ -0,0 +1,27 @@
+// 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/fold_left.hpp>
+#include <boost/hana/tuple.hpp>
+
+#include <sstream>
+namespace hana = boost::hana;
+
+
+auto to_string = [](auto x) {
+    std::ostringstream ss;
+    ss << x;
+    return ss.str();
+};
+
+auto show = [](auto x, auto y) {
+    return "(" + to_string(x) + " + " + to_string(y) + ")";
+};
+
+int main() {
+    BOOST_HANA_RUNTIME_CHECK(
+        hana::fold_left(hana::make_tuple(2, "3", '4'), "1", show) == "(((1 + 2) + 3) + 4)"
+    );
+}