Squashed 'third_party/boostorg/config/' content from commit bb3c8a2

Change-Id: I20e82d188260045e00478e35813b54ca7fda6eaf
git-subtree-dir: third_party/boostorg/config
git-subtree-split: bb3c8a20dcb3a97e0c999a5869305398fa6d8a11
diff --git a/include/boost/config/pragma_message.hpp b/include/boost/config/pragma_message.hpp
new file mode 100644
index 0000000..b2c5ff2
--- /dev/null
+++ b/include/boost/config/pragma_message.hpp
@@ -0,0 +1,31 @@
+#ifndef BOOST_CONFIG_PRAGMA_MESSAGE_HPP_INCLUDED
+#define BOOST_CONFIG_PRAGMA_MESSAGE_HPP_INCLUDED
+
+//  Copyright 2017 Peter Dimov.
+//
+//  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
+//
+//  BOOST_PRAGMA_MESSAGE("message")
+//
+//  Expands to the equivalent of #pragma message("message")
+//
+//  Note that this header is C compatible.
+
+#include <boost/config/helper_macros.hpp>
+
+#if defined(BOOST_DISABLE_PRAGMA_MESSAGE)
+# define BOOST_PRAGMA_MESSAGE(x)
+#elif defined(__INTEL_COMPILER)
+# define BOOST_PRAGMA_MESSAGE(x) __pragma(message(__FILE__ "(" BOOST_STRINGIZE(__LINE__) "): note: " x))
+#elif defined(__GNUC__)
+# define BOOST_PRAGMA_MESSAGE(x) _Pragma(BOOST_STRINGIZE(message(x)))
+#elif defined(_MSC_VER)
+# define BOOST_PRAGMA_MESSAGE(x) __pragma(message(__FILE__ "(" BOOST_STRINGIZE(__LINE__) "): note: " x))
+#else
+# define BOOST_PRAGMA_MESSAGE(x)
+#endif
+
+#endif // BOOST_CONFIG_PRAGMA_MESSAGE_HPP_INCLUDED