Merge commit '4ebe6417a5fce5f0994fc0c31bebf732be96a07c' as 'boost'

boost/libs/serialization/src/singleton.cpp

@@ -0,0 +1,36 @@
+/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
+// singleton.cpp
+//
+// Copyright (c) 201 5 Robert Ramey, Indiana University (garcia@osl.iu.edu)
+// Use, modification and distribution is subject to 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)
+//
+
+// it marks our code with proper attributes as being exported when
+// we're compiling it while marking it import when just the headers
+// is being included.
+#define BOOST_SERIALIZATION_SOURCE
+#include <boost/serialization/config.hpp>
+#include <boost/serialization/singleton.hpp>
+
+namespace boost { 
+namespace serialization { 
+
+bool & singleton_module::get_lock(){
+    static bool lock = false;
+    return lock;
+}
+
+BOOST_SERIALIZATION_DECL void singleton_module::lock(){
+    get_lock() = true;
+}
+BOOST_SERIALIZATION_DECL void singleton_module::unlock(){
+    get_lock() = false;
+}
+BOOST_SERIALIZATION_DECL bool singleton_module::is_locked() {
+    return get_lock();
+}
+
+} // namespace serialization
+} // namespace boost