Rename test/std_ec_mismatch to std_single_instance; test also static and shared libraries

test/std_single_instance_2.cpp

@@ -0,0 +1,34 @@
+
+// Copyright 2019 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/config.hpp>
+
+#if defined(STD_SINGLE_INSTANCE_DYN_LINK)
+# define EXPORT BOOST_SYMBOL_EXPORT
+#else
+# define EXPORT
+#endif
+
+#include <boost/system/error_code.hpp>
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+#include <system_error>
+
+namespace lib2
+{
+
+EXPORT std::error_code get_system_code()
+{
+    return boost::system::error_code( 0, boost::system::system_category() );
+}
+
+EXPORT std::error_code get_generic_code()
+{
+    return boost::system::error_code( 0, boost::system::generic_category() );
+}
+
+} // namespace lib2
+
+#endif