1 files changed, 39 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/scan_left.cpp b/src/boost/libs/hana/example/scan_left.cpp
new file mode 100644
index 000000000..0e176ac13
--- /dev/null
+++ b/src/boost/libs/hana/example/scan_left.cpp
@@ -0,0 +1,39 @@
+// 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/equal.hpp>
+#include <boost/hana/scan_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 f = [](auto state, auto element) {
+    return "f(" + to_string(state) + ", " + to_string(element) + ")";
+};
+
+int main() {
+    // with initial state
+    BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(2, "3", '4'), 1, f) == hana::make_tuple(
+        1,
+        "f(1, 2)",
+        "f(f(1, 2), 3)",
+        "f(f(f(1, 2), 3), 4)"
+    ));
+
+    // without initial state
+    BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(1, "2", '3'), f) == hana::make_tuple(
+        1,
+        "f(1, 2)",
+        "f(f(1, 2), 3)"
+    ));
+}