1 files changed, 59 insertions, 0 deletions
diff --git a/src/third_party/boost-1.69.0/boost/none.hpp b/src/third_party/boost-1.69.0/boost/none.hpp
new file mode 100644
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+++ b/src/third_party/boost-1.69.0/boost/none.hpp
@@ -0,0 +1,59 @@
+// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
+// Copyright (C) 2014, 2015 Andrzej Krzemienski.
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  fernando_cacciola@hotmail.com
+//
+#ifndef BOOST_NONE_17SEP2003_HPP
+#define BOOST_NONE_17SEP2003_HPP
+
+#include "boost/none_t.hpp"
+
+// NOTE: Borland users have to include this header outside any precompiled headers
+// (bcc<=5.64 cannot include instance data in a precompiled header)
+//  -- * To be verified, now that there's no unnamed namespace
+
+namespace boost {
+
+#ifdef BOOST_OPTIONAL_USE_OLD_DEFINITION_OF_NONE
+
+none_t const none = (static_cast<none_t>(0)) ;
+
+#elif defined BOOST_OPTIONAL_USE_SINGLETON_DEFINITION_OF_NONE
+
+namespace detail { namespace optional_detail {
+
+  // the trick here is to make boost::none defined once as a global but in a header file
+  template <typename T>
+  struct none_instance
+  {
+    static const T instance;
+  };
+  
+  template <typename T>
+  const T none_instance<T>::instance = T(); // global, but because 'tis a template, no cpp file required
+
+} } // namespace detail::optional_detail
+
+
+namespace {
+  // TU-local
+  const none_t& none = detail::optional_detail::none_instance<none_t>::instance; 
+}
+
+#else
+
+const none_t none ((none_t::init_tag()));
+
+#endif // older definitions
+
+} // namespace boost
+
+#endif // header guard
+