add C++03 deprecation warnings

Author: apolukhin

include/boost/variant/detail/config.hpp

@@ -16,4 +16,22 @@
 #include <boost/config.hpp>
 #include <boost/detail/workaround.hpp>
 
+#include <boost/config/pragma_message.hpp>
+#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) || \
+    defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) || \
+    defined(BOOST_NO_CXX11_CONSTEXPR) || \
+    defined(BOOST_NO_CXX11_NULLPTR) || \
+    defined(BOOST_NO_CXX11_NOEXCEPT) || \
+    defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) || \
+    defined(BOOST_NO_CXX11_FINAL) || \
+    defined(BOOST_NO_CXX11_ALIGNOF) || \
+    defined(BOOST_NO_CXX11_STATIC_ASSERT) || \
+    defined(BOOST_NO_CXX11_SMART_PTR) || \
+    defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST) || \
+    defined(BOOST_NO_CXX11_HDR_TYPE_TRAITS)
+
+BOOST_PRAGMA_MESSAGE("C++03 support is deprecated in Boost.Variant 1.82 and will be removed in Boost.Variant 1.84.")
+
+#endif
+
 #endif // BOOST_VARIANT_DETAIL_CONFIG_HPP