1 files changed, 99 insertions, 0 deletions
diff --git a/src/seastar/tests/unit/tuple_utils_test.cc b/src/seastar/tests/unit/tuple_utils_test.cc
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+++ b/src/seastar/tests/unit/tuple_utils_test.cc
@@ -0,0 +1,99 @@
+/*
+ * This file is open source software, licensed to you under the terms
+ * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership.  You may not use this file except in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Copyright (C) 2017 ScyllaDB
+ */
+
+#define BOOST_TEST_MODULE core
+
+#include <seastar/util/tuple_utils.hh>
+
+#include <boost/test/included/unit_test.hpp>
+
+#include <sstream>
+#include <type_traits>
+
+using namespace seastar;
+
+BOOST_AUTO_TEST_CASE(map) {
+    const auto pairs = tuple_map(std::make_tuple(10, 5.5, true), [](auto&& e) { return std::make_tuple(e, e); });
+
+    BOOST_REQUIRE(pairs == std::make_tuple(std::make_tuple(10, 10),
+                                           std::make_tuple(5.5, 5.5),
+                                           std::make_tuple(true, true)));
+}
+
+BOOST_AUTO_TEST_CASE(for_each) {
+    std::ostringstream os;
+
+    tuple_for_each(std::make_tuple('a', 10, false, 5.4), [&os](auto&& e) {
+        os << e;
+    });
+
+    BOOST_REQUIRE_EQUAL(os.str(), "a1005.4");
+}
+
+namespace {
+
+template <typename T>
+struct transform_type final {
+    using type = T;
+};
+
+template <>
+struct transform_type<bool> final { using type = int; };
+
+template <>
+struct transform_type<double> final { using type = char; };
+
+}
+
+BOOST_AUTO_TEST_CASE(map_types) {
+    using before_tuple = std::tuple<double, bool, const char*>;
+    using after_tuple = typename tuple_map_types<transform_type, before_tuple>::type;
+
+    BOOST_REQUIRE((std::is_same<after_tuple, std::tuple<char, int, const char*>>::value));
+}
+
+namespace {
+
+//
+// Strip all `bool` fields.
+//
+
+template <typename>
+struct keep_type final {
+    static constexpr auto value = true;
+};
+
+template <>
+struct keep_type<bool> final {
+    static constexpr auto value = false;
+};
+
+}
+
+BOOST_AUTO_TEST_CASE(filter_by_type) {
+    using before_tuple = std::tuple<bool, int, bool, double, bool, char>;
+
+    const auto t = tuple_filter_by_type<keep_type>(before_tuple{true, 10, false, 5.5, true, 'a'});
+    using filtered_type = typename std::decay<decltype(t)>::type;
+
+    BOOST_REQUIRE((std::is_same<filtered_type, std::tuple<int, double, char>>::value));
+    BOOST_REQUIRE(t == std::make_tuple(10, 5.5, 'a'));
+}