+/*
+ * Copyright 2016 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * 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.
+ */
+
+#pragma once
+
+namespace folly {
+namespace detail {
+
+template <typename... Ts>
+struct TryTuple {
+ template <typename... Ts2>
+ static std::tuple<Ts...> unwrap(
+ std::tuple<folly::Try<Ts>...>&& o,
+ Ts2&&... ts2) {
+ static_assert(
+ sizeof...(ts2) < std::tuple_size<std::tuple<folly::Try<Ts>...>>::value,
+ "Non-templated unwrap should be used instead");
+
+ return unwrap(
+ std::move(o),
+ std::forward<Ts2>(ts2)...,
+ std::move(*std::get<sizeof...(ts2)>(o)));
+ }
+
+ static std::tuple<Ts...> unwrap(
+ std::tuple<folly::Try<Ts>...>&& /* o */,
+ Ts&&... ts) {
+ return std::tuple<Ts...>(std::forward<Ts>(ts)...);
+ }
+};
+
+} // namespace detail
+} // namespace folly