1 files changed, 26 insertions, 0 deletions
diff --git a/src/optional.h b/src/optional.h
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index 0000000000..95a3b24d0a
--- /dev/null
+++ b/src/optional.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_OPTIONAL_H
+#define BITCOIN_OPTIONAL_H
+
+#include <utility>
+
+#include <boost/optional.hpp>
+
+//! Substitute for C++17 std::optional
+template <typename T>
+using Optional = boost::optional<T>;
+
+//! Substitute for C++17 std::make_optional
+template <typename T>
+Optional<T> MakeOptional(bool condition, T&& value)
+{
+    return boost::make_optional(condition, std::forward<T>(value));
+}
+
+//! Substitute for C++17 std::nullopt
+static auto& nullopt = boost::none;
+
+#endif // BITCOIN_OPTIONAL_H