build: switch to C++17

Change-Id: Id6217b5c993f3e4726e89773128b565e5f136bb6
diff --git a/tools/peek/ndnpeek/ndnpeek.hpp b/tools/peek/ndnpeek/ndnpeek.hpp
index ce37712..eba1b1f 100644
--- a/tools/peek/ndnpeek/ndnpeek.hpp
+++ b/tools/peek/ndnpeek/ndnpeek.hpp
@@ -35,8 +35,7 @@
 #include <ndn-cxx/link.hpp>
 #include <ndn-cxx/util/scheduler.hpp>
 
-namespace ndn {
-namespace peek {
+namespace ndn::peek {
 
 /**
  * @brief options for NdnPeek
@@ -58,7 +57,7 @@
   optional<time::milliseconds> timeout;
 };
 
-class NdnPeek : boost::noncopyable
+class NdnPeek : noncopyable
 {
 public:
   NdnPeek(Face& face, const PeekOptions& options);
@@ -119,7 +118,6 @@
   Result m_result = Result::UNKNOWN;
 };
 
-} // namespace peek
-} // namespace ndn
+} // namespace ndn::peek
 
 #endif // NDN_TOOLS_NDNPEEK_NDNPEEK_HPP