Use std::function

include/boost/function/detail/config.hpp

@@ -0,0 +1,12 @@
+// Copyright 2019 Peter Dimov
+// 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
+
+#ifndef BOOST_FUNCTION_DETAIL_CONFIG_HPP_INCLUDED
+#define BOOST_FUNCTION_DETAIL_CONFIG_HPP_INCLUDED
+
+#if !defined(BOOST_FUNCTION_ENABLE_CXX03)
+# define BOOST_FUNCTION_ENABLE_CXX03 0
+#endif
+
+#endif // #ifndef BOOST_FUNCTION_DETAIL_CONFIG_HPP_INCLUDED

include/boost/function/detail/maybe_include.hpp

@@ -7,6 +7,10 @@
 
 // For more information, see http://www.boost.org
 
+#include <boost/function/detail/config.hpp>
+
+#if BOOST_FUNCTION_ENABLE_CXX03
+
 #if BOOST_FUNCTION_NUM_ARGS == 0
 #  undef BOOST_FUNCTION_MAX_ARGS_DEFINED
 #  define BOOST_FUNCTION_MAX_ARGS_DEFINED 0
@@ -367,3 +371,5 @@
 #else
 #  error Cannot handle Boost.Function objects that accept more than 50 arguments!
 #endif
+
+#endif