util: backport C++17 optional
This commit also makes code style of parameter packs consistent.
refs #3753
Change-Id: I1e301d25b73501b0b28678e6095bbb5619a0e760
diff --git a/src/util/backports.hpp b/src/util/backports.hpp
index 072d1c7..acb03e6 100644
--- a/src/util/backports.hpp
+++ b/src/util/backports.hpp
@@ -35,7 +35,7 @@
#if __cpp_lib_make_unique
using std::make_unique;
#else
-template<typename T, typename... Args>
+template<typename T, typename ...Args>
inline unique_ptr<T>
make_unique(Args&&... args)
{
@@ -74,4 +74,6 @@
} // namespace ndn
+#include "backports-optional.hpp"
+
#endif // NDN_UTIL_BACKPORTS_HPP